Search Results

Search found 612 results on 25 pages for 'scheduling'.

Page 23/25 | < Previous Page | 19 20 21 22 23 24 25  | Next Page >

  • Server 2003 R2 doesn't allow logon after a few days of uptime

    - by Bryan
    We have a server 2003 R2 standard (which I'll refer to as SRV01) that's knocking on a bit now, but it still acts as a file, print and SQL server on our company's network. SRV01 hosts user profiles, home directories and pretty much all our business data. Note our AD is currently at 2008 R2 level. This server is due to be upgraded in the next 12 months, but I've no budget to spend on it just yet. A bit of history of this server follows: When SRV01 was first commissioned, it acted as a domain controller (with the same 2003 R2 install it has today), paired with another server that ran Server 2003 R2 SBS. A few years ago, we purchased a pair of dedicated DCs (2008 R2) and at this point we decommissioned the 2003 SBS server, and SRV01 was DCPROMOed out of the AD. Up until very recently, SRV01 used to run Exchange 2003, however we've recently purchased a dedicated server for Exchange 2010 and upgraded (following Microsoft recommended upgrade path). Exchange 2003 was recently uninstalled. - Cleanly to the best of my knowledge. Ever since Exchange was removed from SRV01, I'm finding that after a few days of uptime, when I attempt to logon, pressing CTRL-ALT-DEL just hides the Welcome to Windows Server 2003 banner, and never presents the logon dialog. All I see is a moveable mouse pointer and a blank background. It's a similar story with an admin TS session, the RDP client connects and gives me a blank background, but no logon dialog is presented. The RDP session indefinitely hangs until I give up and close it. The only way I've been able to gain access to the server is to pull the plug on it. Whilst the server does have a battery backed up RAID 5 controller, I'm unhappy about having to do this, so as a temporary measure, I've created a scheduled job to reboot SRV01 each night. Not only do I not like the idea of scheduling a reboot of a server like this, but it is also causing problems for users that leave desktop PCs left logged on overnight. Users complain of 'Delayed Write Failures', and there has also been a number of users that have started to complain about account lockout problems, as well as users not able to connect to shares on SRV01 until they reboot their desktop PCs. I've examined event logs on SRV01 and on the DCs looking for clues as to what the problem is, but there really is nothing untoward being logged. How could I being to investigate this problem when nothing of any relevance is being logged? Is there some additional logging that can be enabled that might give some clues as to what could be causing this problem? Could performance monitor help me out here, and if so, what counters would you consider monitoring? It's worth mentioning that whilst the server is unresponsive via the console and TS, it does still respond to clients connecting to shares without problems for several days, but after about a week I then start to hear users reporting problems accessing shares, but this seems quite sporadic. I've also tried leaving the console logged on (and locked), when I notice I can no longer logon via TS, I can unlock the server console without problem, but it refuses to reboot/shutdown, and subsequent attempts to reboot report that a system shutdown is already in progress and the system then completely hangs. I've tried playing the waiting game for several hours thinking that a timeout might allow the shutdown to continue, but to no avail.

    Read the article

  • RAID and Partitions, guidance Needed

    - by beauregarde
    Alright I have a Biostar TA790GX3A2+ Mobo 2x Seagate 750Gb Hard drive (with 2 different speeds) an X4 9750 A GeForce 9800GT and 2GB RAM Hardware Specs link text I want to configure my computer with partitions in various RAID arrays. The Partitions I know i want (disk letters are mostly for reference here) C: XP Boot D: XP Swap E: XP Run F: Games G: Data The Partitions I think I want (repeat caveat) H: small FAT for Win Legacy and DOS I: Linux J: Linux Swap K-?M?: Other Linux /whatever partitions N & O: Attic for D1 and D2 What I'd like to do, is have C: written on Disk 1 (D1),.. D: on D2,.. E: and F: striped on D1 & D2,.. G: mirrored or D1 & D2,.. I: on D2 (so i can just switch disc boot priority to open in Ubuntu),.. J: on D1,.. and H: somewhere low on D1 I am inexperienced with VMs, so i am unsure as to whether those run out of XP, or whether i need to reserve a primary partition for them. However, I think they would be preferable for testing new OS's to scheduling a partition for the same purpose. I'm also not married to XP, but -64 IS pretty important to me. QUestion Time 1) Ignoring the irrationality of it all, is such a configuration possible? If not, can some pseudo-approximation be achieved? 2) My RAID is software, isnt it? 3) How much should I short a 750GB HD? And should i use that space for my attics, or for my attics and something else, or for something else (.iso's perhaps?)? 4) if XP is striped on D1 & D2, will that interfere egregiously with my Swap writes on D2? If so, would striping both XP and Swap relieve (or at least mitigate) that issue? Should XP and Swap just be written normally on 2 different HDs? 5) Should I keep DL's and Drivers on E: (XP Run), F: (Games), or elsewhere? 6) Is 4GB enough for C:? 7) Is 30GB enough (or too much) for E:? 8) How much to reserve for the Linux and sub-Linux partitions? Also, where on the platter do you think i should put them? 9) Am I a fool to use FAT16 instead of FAT32 for H: because I'd rather run 95 than 98SE? If not, do you think 2GB or 4GB? 10) I cant predict what my Max Commit Charge will be, so recommendations for Pagefile size? 5GB? 12GB? 11) VMs, where do I run them? do they exacerbate anything? Would it be better to just emulate Linux, 95, and DOS? EC) What havent I considered that I really should? Notes: computer is mostly for playing games and watching media, though I wouldnt rule out the use of particularly blah-intensive anything.

    Read the article

  • Improving TCP performance over a gigabit network with lots of connections and high traffic of small packets

    - by MinimeDJ
    I’m trying to improve my TCP throughput over a “gigabit network with lots of connections and high traffic of small packets”. My server OS is Ubuntu 11.10 Server 64bit. There are about 50.000 (and growing) clients connected to my server through TCP Sockets (all on the same port). 95% of of my packets have size of 1-150 bytes (TCP header and payload). The rest 5% vary from 150 up to 4096+ bytes. With the config below my server can handle traffic up to 30 Mbps (full duplex). Can you please advice best practice to tune OS for my needs? My /etc/sysctl.cong looks like this: kernel.pid_max = 1000000 net.ipv4.ip_local_port_range = 2500 65000 fs.file-max = 1000000 # net.core.netdev_max_backlog=3000 net.ipv4.tcp_sack=0 # net.core.rmem_max = 16777216 net.core.wmem_max = 16777216 net.core.somaxconn = 2048 # net.ipv4.tcp_rmem = 4096 87380 16777216 net.ipv4.tcp_wmem = 4096 65536 16777216 # net.ipv4.tcp_synack_retries = 2 net.ipv4.tcp_syncookies = 1 net.ipv4.tcp_mem = 50576 64768 98152 # net.core.wmem_default = 65536 net.core.rmem_default = 65536 net.ipv4.tcp_window_scaling=1 # net.ipv4.tcp_mem= 98304 131072 196608 # net.ipv4.tcp_timestamps = 0 net.ipv4.tcp_rfc1337 = 1 net.ipv4.ip_forward = 0 net.ipv4.tcp_congestion_control=cubic net.ipv4.tcp_tw_recycle = 0 net.ipv4.tcp_tw_reuse = 0 # net.ipv4.tcp_orphan_retries = 1 net.ipv4.tcp_fin_timeout = 25 net.ipv4.tcp_max_orphans = 8192 Here are my limits: $ ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 193045 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 1000000 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 8192 cpu time (seconds, -t) unlimited max user processes (-u) 1000000 [ADDED] My NICs are the following: $ dmesg | grep Broad [ 2.473081] Broadcom NetXtreme II 5771x 10Gigabit Ethernet Driver bnx2x 1.62.12-0 (2011/03/20) [ 2.477808] bnx2x 0000:02:00.0: eth0: Broadcom NetXtreme II BCM57711E XGb (A0) PCI-E x4 5GHz (Gen2) found at mem fb000000, IRQ 28, node addr d8:d3:85:bd:23:08 [ 2.482556] bnx2x 0000:02:00.1: eth1: Broadcom NetXtreme II BCM57711E XGb (A0) PCI-E x4 5GHz (Gen2) found at mem fa000000, IRQ 40, node addr d8:d3:85:bd:23:0c [ADDED 2] ethtool -k eth0 Offload parameters for eth0: rx-checksumming: on tx-checksumming: on scatter-gather: on tcp-segmentation-offload: on udp-fragmentation-offload: off generic-segmentation-offload: on generic-receive-offload: on large-receive-offload: on rx-vlan-offload: on tx-vlan-offload: on ntuple-filters: off receive-hashing: off [ADDED 3] sudo ethtool -S eth0|grep -vw 0 NIC statistics: [1]: rx_bytes: 17521104292 [1]: rx_ucast_packets: 118326392 [1]: tx_bytes: 35351475694 [1]: tx_ucast_packets: 191723897 [2]: rx_bytes: 16569945203 [2]: rx_ucast_packets: 114055437 [2]: tx_bytes: 36748975961 [2]: tx_ucast_packets: 194800859 [3]: rx_bytes: 16222309010 [3]: rx_ucast_packets: 109397802 [3]: tx_bytes: 36034786682 [3]: tx_ucast_packets: 198238209 [4]: rx_bytes: 14884911384 [4]: rx_ucast_packets: 104081414 [4]: rx_discards: 5828 [4]: rx_csum_offload_errors: 1 [4]: tx_bytes: 35663361789 [4]: tx_ucast_packets: 194024824 [5]: rx_bytes: 16465075461 [5]: rx_ucast_packets: 110637200 [5]: tx_bytes: 43720432434 [5]: tx_ucast_packets: 202041894 [6]: rx_bytes: 16788706505 [6]: rx_ucast_packets: 113123182 [6]: tx_bytes: 38443961940 [6]: tx_ucast_packets: 202415075 [7]: rx_bytes: 16287423304 [7]: rx_ucast_packets: 110369475 [7]: rx_csum_offload_errors: 1 [7]: tx_bytes: 35104168638 [7]: tx_ucast_packets: 184905201 [8]: rx_bytes: 12689721791 [8]: rx_ucast_packets: 87616037 [8]: rx_discards: 2638 [8]: tx_bytes: 36133395431 [8]: tx_ucast_packets: 196547264 [9]: rx_bytes: 15007548011 [9]: rx_ucast_packets: 98183525 [9]: rx_csum_offload_errors: 1 [9]: tx_bytes: 34871314517 [9]: tx_ucast_packets: 188532637 [9]: tx_mcast_packets: 12 [10]: rx_bytes: 12112044826 [10]: rx_ucast_packets: 84335465 [10]: rx_discards: 2494 [10]: tx_bytes: 36562151913 [10]: tx_ucast_packets: 195658548 [11]: rx_bytes: 12873153712 [11]: rx_ucast_packets: 89305791 [11]: rx_discards: 2990 [11]: tx_bytes: 36348541675 [11]: tx_ucast_packets: 194155226 [12]: rx_bytes: 12768100958 [12]: rx_ucast_packets: 89350917 [12]: rx_discards: 2667 [12]: tx_bytes: 35730240389 [12]: tx_ucast_packets: 192254480 [13]: rx_bytes: 14533227468 [13]: rx_ucast_packets: 98139795 [13]: tx_bytes: 35954232494 [13]: tx_ucast_packets: 194573612 [13]: tx_bcast_packets: 2 [14]: rx_bytes: 13258647069 [14]: rx_ucast_packets: 92856762 [14]: rx_discards: 3509 [14]: rx_csum_offload_errors: 1 [14]: tx_bytes: 35663586641 [14]: tx_ucast_packets: 189661305 rx_bytes: 226125043936 rx_ucast_packets: 1536428109 rx_bcast_packets: 351 rx_discards: 20126 rx_filtered_packets: 8694 rx_csum_offload_errors: 11 tx_bytes: 548442367057 tx_ucast_packets: 2915571846 tx_mcast_packets: 12 tx_bcast_packets: 2 tx_64_byte_packets: 35417154 tx_65_to_127_byte_packets: 2006984660 tx_128_to_255_byte_packets: 373733514 tx_256_to_511_byte_packets: 378121090 tx_512_to_1023_byte_packets: 77643490 tx_1024_to_1522_byte_packets: 43669214 tx_pause_frames: 228 Some info about SACK: When to turn TCP SACK off?

    Read the article

  • cherrypy fails to stop when puppet tries to ensure running and refresh it at the same time

    - by ento
    I am trying to manage a cherrypy service with puppet. However, when the configuration is applied, cherryd ends up with no PID file although the process is up and running. Since the PID file is lost I can no longer stop the process with /etc/init.d/mycherryd stop (unless I modify the handmade init script to lookup the PID with ps or something.) $ /etc/init.d/mycherryd status cherryd dead but subsys locked The problem seems to be that puppet is trying to refresh/restart cherryd (triggered by changes in configuration files) immediately after ensuring it's running (as specified in the manifest), and cherrypy fails to stop and start (restart) itself while still executing its startup process. Is there a clear cut solution to this problem? Is this a bug on the cherrypy side, or can I write a puppet manifest so refresh is called only after the service is up and running? Any suggestion welcome. cherrypy log See how cherrypy catches SIGTERM midway through startup and still starts to listen. :cherrypy.error[18666] 2010-02-12 13:10:23,551 INFO: ENGINE Listening for SIGHUP. :cherrypy.error[18666] 2010-02-12 13:10:23,552 INFO: ENGINE Listening for SIGTERM. :cherrypy.error[18666] 2010-02-12 13:10:23,552 INFO: ENGINE Listening for SIGUSR1. :cherrypy.error[18666] 2010-02-12 13:10:23,552 INFO: ENGINE Bus STARTING :cherrypy.error[18671] 2010-02-12 13:10:23,554 INFO: ENGINE Daemonized to PID: 18671 :cherrypy.error[18671] 2010-02-12 13:10:23,554 INFO: ENGINE PID 18671 written to '/var/mycherryd/cherry.pid'. :cherrypy.error[18671] 2010-02-12 13:10:23,555 INFO: ENGINE Started monitor thread '_TimeoutMonitor'. :cherrypy.error[18670] 2010-02-12 13:10:23,556 INFO: ENGINE Forking twice. :cherrypy.error[18666] 2010-02-12 13:10:23,557 INFO: ENGINE Forking once. :cherrypy.error[18671] 2010-02-12 13:10:23,716 INFO: ENGINE Caught signal SIGTERM. :cherrypy.error[18671] 2010-02-12 13:10:23,716 INFO: ENGINE Bus STOPPING :cherrypy.error[18671] 2010-02-12 13:10:23,716 INFO: ENGINE HTTP Server cherrypy._cpwsgi_server.CPWSGIServer(('0.0.0.0', 12380)) already shut down :cherrypy.error[18671] 2010-02-12 13:10:23,717 INFO: ENGINE Stopped thread '_TimeoutMonitor'. :cherrypy.error[18671] 2010-02-12 13:10:23,717 INFO: ENGINE Bus STOPPED :cherrypy.error[18671] 2010-02-12 13:10:23,732 INFO: ENGINE Bus EXITING :cherrypy.error[18671] 2010-02-12 13:10:23,759 INFO: ENGINE PID file removed: '/var/mycherryd/cherry.pid'. :cherrypy.error[18671] 2010-02-12 13:10:23,782 INFO: ENGINE Bus EXITED :cherrypy.error[18671] 2010-02-12 13:10:23,792 INFO: ENGINE Serving on 0.0.0.0:12380 :cherrypy.error[18671] 2010-02-12 13:10:23,826 INFO: ENGINE Bus STARTED puppet log puppet tries to refresh the service immediately after ensuring it to be 'running'. Feb 12 13:10:22 localhost puppetd[8159]: (//mycherrypy/File[conffiles]) Scheduling refresh of Service[cherryd] Feb 12 13:10:22 localhost last message repeated 12 times Feb 12 13:10:23 localhost puppetd[8159]: (//mycherrypy/Service[mycherryd]/ensure) ensure changed 'stopped' to 'running' Feb 12 13:10:23 localhost puppetd[8159]: (//mycherrypy/Service[mycherryd]) Triggering 'refresh' from 13 dependencies Feb 12 13:11:23 localhost puppetd[8159]: (//mycherrypy/Service[mycherryd]) Failed to call refresh on Service[mycherryd]: Could not stop Service[mycherryd]: Execution of '/sbin/service mycherryd stop' returned 1: at /etc/puppet/manifests/mycherrypy.pp:161 Feb 12 13:11:24 localhost puppetd[8159]: Value of 'preferred_serialization_format' (pson) is invalid for report, using default (marshal) Feb 12 13:11:24 localhost puppetd[8159]: Finished catalog run in 99.25 seconds puppet manifest excerpt class mycherrypy { file { 'rpm': path => "/tmp/${apiserver}.i386.rpm", source => "${fileserver}/${apiserver}.i386.rpm"; 'conffiles': require => Package["${apiserver}"], path => "${service_home}/config/", ensure => present, source => "${fileserver}/config/", notify => Service["mycherryd"]; } package { "$apiserver": provider => 'rpm', source => "/tmp/${apiserver}.i386.rpm", ensure => latest; } service { "mycherryd": require => [File["conffiles"], Package["${apiserver}"]], ensure => running, provider => redhat, hasstatus => true; } }

    Read the article

  • cherrypy fails to stop when puppet tries to ensure running and refresh it at the same time

    - by ento
    I am trying to manage a cherrypy service with puppet. However, when the configuration is applied, cherryd ends up with no PID file although the process is up and running. Since the PID file is lost I can no longer stop the process with /etc/init.d/mycherryd stop (unless I modify the handmade init script to lookup the PID with ps or something.) $ /etc/init.d/mycherryd status cherryd dead but subsys locked The problem seems to be that puppet is trying to refresh/restart cherryd (triggered by changes in configuration files) immediately after ensuring it's running (as specified in the manifest), and cherrypy fails to stop and start (restart) itself while still executing its startup process. Is there a clear cut solution to this problem? Is this a bug on the cherrypy side, or can I write a puppet manifest so refresh is called only after the service is up and running? Any suggestion welcome. cherrypy log See how cherrypy catches SIGTERM midway through startup and still starts to listen. :cherrypy.error[18666] 2010-02-12 13:10:23,551 INFO: ENGINE Listening for SIGHUP. :cherrypy.error[18666] 2010-02-12 13:10:23,552 INFO: ENGINE Listening for SIGTERM. :cherrypy.error[18666] 2010-02-12 13:10:23,552 INFO: ENGINE Listening for SIGUSR1. :cherrypy.error[18666] 2010-02-12 13:10:23,552 INFO: ENGINE Bus STARTING :cherrypy.error[18671] 2010-02-12 13:10:23,554 INFO: ENGINE Daemonized to PID: 18671 :cherrypy.error[18671] 2010-02-12 13:10:23,554 INFO: ENGINE PID 18671 written to '/var/mycherryd/cherry.pid'. :cherrypy.error[18671] 2010-02-12 13:10:23,555 INFO: ENGINE Started monitor thread '_TimeoutMonitor'. :cherrypy.error[18670] 2010-02-12 13:10:23,556 INFO: ENGINE Forking twice. :cherrypy.error[18666] 2010-02-12 13:10:23,557 INFO: ENGINE Forking once. :cherrypy.error[18671] 2010-02-12 13:10:23,716 INFO: ENGINE Caught signal SIGTERM. :cherrypy.error[18671] 2010-02-12 13:10:23,716 INFO: ENGINE Bus STOPPING :cherrypy.error[18671] 2010-02-12 13:10:23,716 INFO: ENGINE HTTP Server cherrypy._cpwsgi_server.CPWSGIServer(('0.0.0.0', 12380)) already shut down :cherrypy.error[18671] 2010-02-12 13:10:23,717 INFO: ENGINE Stopped thread '_TimeoutMonitor'. :cherrypy.error[18671] 2010-02-12 13:10:23,717 INFO: ENGINE Bus STOPPED :cherrypy.error[18671] 2010-02-12 13:10:23,732 INFO: ENGINE Bus EXITING :cherrypy.error[18671] 2010-02-12 13:10:23,759 INFO: ENGINE PID file removed: '/var/mycherryd/cherry.pid'. :cherrypy.error[18671] 2010-02-12 13:10:23,782 INFO: ENGINE Bus EXITED :cherrypy.error[18671] 2010-02-12 13:10:23,792 INFO: ENGINE Serving on 0.0.0.0:12380 :cherrypy.error[18671] 2010-02-12 13:10:23,826 INFO: ENGINE Bus STARTED puppet log puppet tries to refresh the service immediately after ensuring it to be 'running'. Feb 12 13:10:22 localhost puppetd[8159]: (//mycherrypy/File[conffiles]) Scheduling refresh of Service[cherryd] Feb 12 13:10:22 localhost last message repeated 12 times Feb 12 13:10:23 localhost puppetd[8159]: (//mycherrypy/Service[mycherryd]/ensure) ensure changed 'stopped' to 'running' Feb 12 13:10:23 localhost puppetd[8159]: (//mycherrypy/Service[mycherryd]) Triggering 'refresh' from 13 dependencies Feb 12 13:11:23 localhost puppetd[8159]: (//mycherrypy/Service[mycherryd]) Failed to call refresh on Service[mycherryd]: Could not stop Service[mycherryd]: Execution of '/sbin/service mycherryd stop' returned 1: at /etc/puppet/manifests/mycherrypy.pp:161 Feb 12 13:11:24 localhost puppetd[8159]: Value of 'preferred_serialization_format' (pson) is invalid for report, using default (marshal) Feb 12 13:11:24 localhost puppetd[8159]: Finished catalog run in 99.25 seconds puppet manifest excerpt class mycherrypy { file { 'rpm': path => "/tmp/${apiserver}.i386.rpm", source => "${fileserver}/${apiserver}.i386.rpm"; 'conffiles': require => Package["${apiserver}"], path => "${service_home}/config/", ensure => present, source => "${fileserver}/config/", notify => Service["mycherryd"]; } package { "$apiserver": provider => 'rpm', source => "/tmp/${apiserver}.i386.rpm", ensure => latest; } service { "mycherryd": require => [File["conffiles"], Package["${apiserver}"]], ensure => running, provider => redhat, hasstatus => true; } }

    Read the article

  • Why do we need different CPU architecture for server & mini/mainframe & mixed-core?

    - by claws
    Hello, I was just wondering what other CPU architectures are available other than INTEL & AMD. So, found List of CPU architectures on Wikipedia. It categorizes notable CPU architectures into following categories. Embedded CPU architectures Microcomputer CPU architectures Workstation/Server CPU architectures Mini/Mainframe CPU architectures Mixed core CPU architectures I was analyzing the purposes and have few doubts. I taking Microcomputer CPU (PC) architecture as reference and comparing others. Embedded CPU architecture: They are a completely new world. Embedded systems are small & do very specific task mostly real time & low power consuming so we do not need so many & such wide registers available in a microcomputer CPU (typical PC). In other words we do need a new small & tiny architecture. Hence new architecture & new instruction RISC. The above point also clarifies why do we need a separate operating system (RTOS). Workstation/Server CPU architectures I don't know what is a workstation. Someone clarify regarding the workstation. As of the server. It is dedicated to run a specific software (server software like httpd, mysql etc.). Even if other processes run we need to give server process priority therefore there is a need for new scheduling scheme and thus we need operating system different than general purpose one. If you have any more points for the need of server OS please mention. But I don't get why do we need a new CPU Architecture. Why cant Microcomputer CPU architecture do the job. Can someone please clarify? Mini/Mainframe CPU architectures Again I don't know what are these & what miniframes or mainframes used for? I just know they are very big and occupy complete floor. But I never read about some real world problems they are trying to solve. If any one working on one of these. Share your knowledge. Can some one clarify its purpose & why is it that microcomputer CPU archicture not suitable for it? Is there a new kind of operating system for this too? Why? Mixed core CPU architectures Never heard of these. If possible please keep your answer in this format: XYZ CPU architectures Purpose of XYZ Need for a new architecture. why can't current microcomputer CPU architecture work? They go upto 3GHZ & have upto 8 cores. Need for a new Operating System Why do we need a new kind of operating system for this kind of archictures?

    Read the article

  • How to stop Apache from crashing my entire server?

    - by CyberShadow
    I maintain a Gentoo server with a few services, including Apache. It's fairly low-end (2GB of RAM and a low-end CPU with 2 cores). My problem is that, despite my best efforts, an over-loaded Apache crashes the entire server. In fact, at this point I'm close to being convinced that Linux is a horrible operating system that isn't worth anyone's time looking for stability under load. Things I tried: Adjusting oom_adj for the root Apache process (and thus all its children). That had close to no effect. When Apache was overloaded it would bring the system to a grind, as the system paged out everything else before it got to kill anything. Turning off swap. Didn't help, it would unload memory paged to binaries of processes and other files on /, thus causing the same effect. Putting it in a memory-limited cgroup (limited to 512 MB of RAM, 1/4th of the total). This "worked", at least in my own stress tests - except the server keeps crashing under load (basically stalling all other processes, inaccessible via SSH, etc.) Running it with idle I/O priority. This wasn't a very good idea in the end, because it just caused the system load to climb indefinitely (into the thousands) with almost no visible effect - until you tried to access an unbuffered part of the disk. This caused the task to freeze. (So much for good I/O scheduling, eh?) Limiting the number of concurrent connections to Apache. Setting the number too low caused web sites to become unresponsive due to most slots being occupied with long requests (file downloads). I tried various Apache MPMs without much success (prefork, event, itk). Switching from prefork/event+php-cgi+suphp to itk+mod_php. This improved performance, but didn't solve the actual problem. Switching I/O schedulers (cfq to deadline). Just to stress this out: I don't care if Apache itself goes down under load, I just want the rest of my system to remain stable. Of course, having Apache recover quickly after a brief period of intensive load would be great to have, but one step at a time. Right now I am mostly dumbfounded by how can humanity, in this day and age, design an operating system where such a seemingly simple task (don't allow one system component to crash the entire system) seems practically impossible - or at least, very hard to do. Please don't suggest things like VMs or "BUY MORE RAM". Some more information gathered with a friend's help: The processes hang when the cgroup oom killer is invoked. Here's the call trace: [<ffffffff8104b94b>] ? prepare_to_wait+0x70/0x7b [<ffffffff810a9c73>] mem_cgroup_handle_oom+0xdf/0x180 [<ffffffff810a9559>] ? memcg_oom_wake_function+0x0/0x6d [<ffffffff810aa041>] __mem_cgroup_try_charge+0x32d/0x478 [<ffffffff810aac67>] mem_cgroup_charge_common+0x48/0x73 [<ffffffff81081c98>] ? __lru_cache_add+0x60/0x62 [<ffffffff810aadc3>] mem_cgroup_newpage_charge+0x3b/0x4a [<ffffffff8108ec38>] handle_mm_fault+0x305/0x8cf [<ffffffff813c6276>] ? schedule+0x6ae/0x6fb [<ffffffff8101f568>] do_page_fault+0x214/0x22b [<ffffffff813c7e1f>] page_fault+0x1f/0x30 At this point, the apache memory cgroup is practically deadlocked, and burning CPU in syscalls (all with the above call trace). This seems like a problem in the cgroup implementation...

    Read the article

  • Troubleshooting Website problems within the local network

    - by HaydnWVN
    Have an external website which opens fine on some PC's, yet seems to time out (or symptoms of timing out, but never actually does) on others. Seems to only affect (some) of our newer HP Pro 3305 MT Workstations. All of which are running Win7 32bit SP1 with all updates. Older PC's (Win7 32bit SP1 & WinXP) are unaffected. Using Google Chrome & Firefox makes no difference. Opening the website in IE9 Compatibility Mode has exactly the same symptoms. All PC's are on the same local network (Workgroup) using the same DNS server & gateway (inhouse) on the same internet connection, on the same subnet. There is no proxy server, no content filtering, no load balancing etc etc. Only group policy in effect (locally) is for Update scheduling. Local firewalls are all the same (Kaspersky WP4) and our external facing firewall has no IP specific settings. I have no control over the external website, traceroute shows the same destination on all PC's. It is a fairly popular website in our industry (Horticulture) and i'm not aware of any other people (even other sites within our sister companies) with the same problem. Update: Used Fiddler2 to monitor the HTTP request, seems its not getting fulfilled for some reason?! Request sent: GET http://www.rhs.org.uk/ HTTP/1.1 Host: www.rhs.org.uk Connection: keep-alive User-Agent: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.47 Safari/536.11 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Encoding: gzip,deflate,sdch Accept-Language: en-GB,en-US;q=0.8,en;q=0.6 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Log from Fiddler 2 of the request: This session is not yet complete. Press F5 to refresh when session is complete for updated statistics. Request Count: 1 Bytes Sent: 567 (headers:567; body:0) Bytes Received: 0 (headers:0; body:0) ACTUAL PERFORMANCE -------------- ClientConnected: 17:02:33.720 ClientBeginRequest: 17:02:39.118 GotRequestHeaders: 17:02:39.118 ClientDoneRequest: 17:02:39.118 Determine Gateway: 0ms DNS Lookup: 0ms TCP/IP Connect: 46ms HTTPS Handshake: 0ms ServerConnected: 17:02:39.165 FiddlerBeginRequest: 17:02:39.165 ServerGotRequest: 17:02:39.165 ServerBeginResponse: 00:00:00.000 GotResponseHeaders: 00:00:00.000 ServerDoneResponse: 00:00:00.000 ClientBeginResponse: 00:00:00.000 ClientDoneResponse: 00:00:00.000 RESPONSE BYTES (by Content-Type) -------------- ~headers~: 0 Log of a successful request from a working PC (done this morning, excuse the timestamps being different from above): Request Count: 1 Bytes Sent: 493 (headers:493; body:0) Bytes Received: 20,413 (headers:525; body:19,888) ACTUAL PERFORMANCE -------------- ClientConnected: 08:22:47.766 ClientBeginRequest: 08:22:47.766 GotRequestHeaders: 08:22:47.766 ClientDoneRequest: 08:22:47.766 Determine Gateway: 0ms DNS Lookup: 26ms TCP/IP Connect: 30ms HTTPS Handshake: 0ms ServerConnected: 08:22:47.828 FiddlerBeginRequest: 08:22:47.828 ServerGotRequest: 08:22:47.828 ServerBeginResponse: 08:22:48.905 GotResponseHeaders: 08:22:48.905 ServerDoneResponse: 08:22:48.905 ClientBeginResponse: 08:22:48.905 ClientDoneResponse: 08:22:48.905 Overall Elapsed: 00:00:01.1388020 RESPONSE BYTES (by Content-Type) -------------- text/html: 19,888 ~headers~: 525 So my question has evolved into: What is the difference between the 2 requests and how do I determine why 1 PC is not getting a reply to it's GET request?

    Read the article

  • "Can't create table" when having to many partitions

    - by Chris
    I am currently having a problem I dont understand. Wherever I look it says mySQL (5.5) / InnoDB doesnt have a table limit. I wanted to test the InnoDB compression and was about to create an empty copy of an existing table and ran into the following problem. this one works: CREATE TABLE `hsc` ( LOTS OF STUFF ) ENGINE=InnoDB CHARSET=utf8 PARTITION BY RANGE (pid) SUBPARTITION BY HASH (cons) SUBPARTITIONS 2 (PARTITION hsc_p0 VALUES LESS THAN (10000) , PARTITION hsc_p1 VALUES LESS THAN (20000) , PARTITION hsc_p2 VALUES LESS THAN (30000) , PARTITION hsc_p3 VALUES LESS THAN (40000) , PARTITION hsc_p4 VALUES LESS THAN (50000) , PARTITION hsc_p40 VALUES LESS THAN (4000000) ); this one doesn't: CREATE TABLE `hsc` ( LOTS OF STUFF ) ENGINE=InnoDB CHARSET=utf8 PARTITION BY RANGE (pid) SUBPARTITION BY HASH (cons) SUBPARTITIONS 2 (PARTITION hsc_p0 VALUES LESS THAN (10000) , PARTITION hsc_p1 VALUES LESS THAN (20000) , PARTITION hsc_p2 VALUES LESS THAN (30000) , PARTITION hsc_p3 VALUES LESS THAN (40000) , PARTITION hsc_p4 VALUES LESS THAN (50000) , PARTITION hsc_p5 VALUES LESS THAN (75000) , PARTITION hsc_p6 VALUES LESS THAN (100000) , PARTITION hsc_p7 VALUES LESS THAN (125000) , PARTITION hsc_p8 VALUES LESS THAN (150000) , PARTITION hsc_p9 VALUES LESS THAN (175000) , PARTITION hsc_p40 VALUES LESS THAN (4000000) ); ERROR 1005 (HY000): Can't create table 'hsc' (errno: 1) Its reproducable by removing the number of partitions and adding them again. it does not have to do anything with the name of the table as i tried various names. there is also enough empty space on the HDD. /dev/simfs 230G 26G 192G 12% /var/lib/mysql.mnt There should be no limit on the partitions http://dev.mysql.com/doc/refman/5.5/en/partitioning-limitations.html Maximum number of partitions. The maximum possible number of partitions for a given table (that does not use the NDB storage engine) is 1024. This number includes subpartitions. i have increased both open_files show variables where variable_name LIKE '%open_files%'; +-------------------+-------+ | Variable_name | Value | +-------------------+-------+ | innodb_open_files | 512 | | open_files_limit | 1536 | +-------------------+-------+ No change. Any clues where should I start looking? UPDATE: the whole thing is running in an openvz environment. i saw in users_beancounters that the numflock was a problem, so i increased it. but the problem still persists. maybe this helps: ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 515011 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 1024 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 10240 cpu time (seconds, -t) unlimited max user processes (-u) 515011 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited cat /proc/user_beancounters Version: 2.5 uid resource held maxheld barrier limit failcnt 200: kmemsize 9309653 13357056 14372700 14790164 0 lockedpages 0 1008 2048 2048 0 privvmpages 675424 686528 1048576 1572864 0 shmpages 33 673 21504 21504 0 dummy 0 0 9223372036854775807 9223372036854775807 0 numproc 49 90 240 240 0 physpages 243761 246945 0 9223372036854775807 0 vmguarpages 0 0 1048576 1048576 0 oomguarpages 81672 83305 1048576 1048576 0 numtcpsock 6 8 360 360 0 numflock 175 188 512 512 8 numpty 1 9 16 16 0 numsiginfo 0 48 256 256 0 tcpsndbuf 104640 263912 1720320 2703360 0 tcprcvbuf 98304 131072 1720320 2703360 0 othersockbuf 32368 89304 1126080 2097152 0 dgramrcvbuf 0 2312 262144 262144 0 numothersock 19 28 360 360 0 dcachesize 2285052 3624426 3409920 3624960 0 numfile 616 870 9312 9312 0 dummy 0 0 9223372036854775807 9223372036854775807 0 dummy 0 0 9223372036854775807 9223372036854775807 0 dummy 0 0 9223372036854775807 9223372036854775807 0 numiptent 24 24 128 128 0

    Read the article

  • Distributed and/or Parallel SSIS processing

    - by Jeff
    Background: Our company hosts SaaS DSS applications, where clients provide us data Daily and/or Weekly, which we process & merge into their existing database. During business hours, load in the servers are pretty minimal as it's mostly users running simple pre-defined queries via the website, or running drill-through reports that mostly hit the SSAS OLAP cube. I manage the IT Operations Team, and so far this has presented an interesting "scaling" issue for us. For our daily-refreshed clients, the server is only "busy" for about 4-6 hrs at night. For our weekly-refresh clients, the server is only "busy" for maybe 8-10 hrs per week! We've done our best to use some simple methods of distributing the load by spreading the daily clients evenly among the servers such that we're not trying to process daily clients back-to-back over night. But long-term this scaling strategy creates two notable issues. First, it's going to consume a pretty immense amount of hardware that sits idle for large periods of time. Second, it takes significant Production Support over-head to basically "schedule" the ETL such that they don't over-lap, and move clients/schedules around if they out-grow the resources on a particular server or allocated time-slot. As the title would imply, one option we've tried is running multiple SSIS packages in parallel, but in most cases this has yielded VERY inconsistent results. The most common failures are DTExec, SQL, and SSAS fighting for physical memory and throwing out-of-memory errors, and ETLs running 3,4,5x longer than expected. So from my practical experience thus far, it seems like running multiple ETL packages on the same hardware isn't a good idea, but I can't be the first person that doesn't want to scale multiple ETLs around manual scheduling, and sequential processing. One option we've considered is virtualizing the servers, which obviously doesn't give you any additional resources, but moves the resource contention onto the hypervisor, which (from my experience) seems to manage simultaneous CPU/RAM/Disk I/O a little more gracefully than letting DTExec, SQL, and SSAS battle it out within Windows. Question to the forum: So my question to the forum is, are we missing something obvious here? Are there tools out there that can help manage running multiple SSIS packages on the same hardware? Would it be more "efficient" in terms of parallel execution if instead of running DTExec, SQL, and SSAS same machine (with every machine running that configuration), we run in pairs of three machines with SSIS running on one machine, SQL on another, and SSAS on a third? Obviously that would only make sense if we could process more than the three ETL we were able to process on the machine independently. Another option we've considered is completely re-architecting our SSIS package to have one "master" package for all clients that attempts to intelligently chose a server based off how "busy" it already is in terms of CPU/Memory/Disk utilization, but that would be a herculean effort, and seems like we're trying to reinvent something that you would think someone would sell (although I haven't had any luck finding it). So in summary, are we missing an obvious solution for this, and does anyone know if any tools (for free or for purchase, doesn't matter) that facilitate running multiple SSIS ETL packages in parallel and on multiple servers? (What I would call a "queue & node based" system, but that's not an official term). Ultimately VMWare's Distributed Resource Scheduler addresses this as you simply run a consistent number of clients per VM that you know will never conflict scheduleing-wise, then leave it up to VMWare to move the VMs around to balance out hardware usage. I'm definitely not against using VMWare to do this, but since we're a 100% Microsoft app stack, it seems like -someone- out there would have solved this problem at the application layer instead of the hypervisor layer by checking on resource utilization at the OS, SQL, SSAS levels. I'm open to ANY discussion on this, and remember no suggestion is too crazy or radical! :-) Right now, VMWare is the only option we've found to get away from "manually" balancing our resources, so any suggestions that leave us on a pure Microsoft stack would be great. Thanks guys, Jeff

    Read the article

  • Parallelism in .NET – Part 10, Cancellation in PLINQ and the Parallel class

    - by Reed
    Many routines are parallelized because they are long running processes.  When writing an algorithm that will run for a long period of time, its typically a good practice to allow that routine to be cancelled.  I previously discussed terminating a parallel loop from within, but have not demonstrated how a routine can be cancelled from the caller’s perspective.  Cancellation in PLINQ and the Task Parallel Library is handled through a new, unified cooperative cancellation model introduced with .NET 4.0. Cancellation in .NET 4 is based around a new, lightweight struct called CancellationToken.  A CancellationToken is a small, thread-safe value type which is generated via a CancellationTokenSource.  There are many goals which led to this design.  For our purposes, we will focus on a couple of specific design decisions: Cancellation is cooperative.  A calling method can request a cancellation, but it’s up to the processing routine to terminate – it is not forced. Cancellation is consistent.  A single method call requests a cancellation on every copied CancellationToken in the routine. Let’s begin by looking at how we can cancel a PLINQ query.  Supposed we wanted to provide the option to cancel our query from Part 6: double min = collection .AsParallel() .Min(item => item.PerformComputation()); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } We would rewrite this to allow for cancellation by adding a call to ParallelEnumerable.WithCancellation as follows: var cts = new CancellationTokenSource(); // Pass cts here to a routine that could, // in parallel, request a cancellation try { double min = collection .AsParallel() .WithCancellation(cts.Token) .Min(item => item.PerformComputation()); } catch (OperationCanceledException e) { // Query was cancelled before it finished } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, if the user calls cts.Cancel() before the PLINQ query completes, the query will stop processing, and an OperationCanceledException will be raised.  Be aware, however, that cancellation will not be instantaneous.  When cts.Cancel() is called, the query will only stop after the current item.PerformComputation() elements all finish processing.  cts.Cancel() will prevent PLINQ from scheduling a new task for a new element, but will not stop items which are currently being processed.  This goes back to the first goal I mentioned – Cancellation is cooperative.  Here, we’re requesting the cancellation, but it’s up to PLINQ to terminate. If we wanted to allow cancellation to occur within our routine, we would need to change our routine to accept a CancellationToken, and modify it to handle this specific case: public void PerformComputation(CancellationToken token) { for (int i=0; i<this.iterations; ++i) { // Add a check to see if we've been canceled // If a cancel was requested, we'll throw here token.ThrowIfCancellationRequested(); // Do our processing now this.RunIteration(i); } } With this overload of PerformComputation, each internal iteration checks to see if a cancellation request was made, and will throw an OperationCanceledException at that point, instead of waiting until the method returns.  This is good, since it allows us, as developers, to plan for cancellation, and terminate our routine in a clean, safe state. This is handled by changing our PLINQ query to: try { double min = collection .AsParallel() .WithCancellation(cts.Token) .Min(item => item.PerformComputation(cts.Token)); } catch (OperationCanceledException e) { // Query was cancelled before it finished } PLINQ is very good about handling this exception, as well.  There is a very good chance that multiple items will raise this exception, since the entire purpose of PLINQ is to have multiple items be processed concurrently.  PLINQ will take all of the OperationCanceledException instances raised within these methods, and merge them into a single OperationCanceledException in the call stack.  This is done internally because we added the call to ParallelEnumerable.WithCancellation. If, however, a different exception is raised by any of the elements, the OperationCanceledException as well as the other Exception will be merged into a single AggregateException. The Task Parallel Library uses the same cancellation model, as well.  Here, we supply our CancellationToken as part of the configuration.  The ParallelOptions class contains a property for the CancellationToken.  This allows us to cancel a Parallel.For or Parallel.ForEach routine in a very similar manner to our PLINQ query.  As an example, we could rewrite our Parallel.ForEach loop from Part 2 to support cancellation by changing it to: try { var cts = new CancellationTokenSource(); var options = new ParallelOptions() { CancellationToken = cts.Token }; Parallel.ForEach(customers, options, customer => { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // Check for cancellation here options.CancellationToken.ThrowIfCancellationRequested(); // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { theStore.EmailCustomer(customer); customer.LastEmailContact = DateTime.Now; } }); } catch (OperationCanceledException e) { // The loop was cancelled } Notice that here we use the same approach taken in PLINQ.  The Task Parallel Library will automatically handle our cancellation in the same manner as PLINQ, providing a clean, unified model for cancellation of any parallel routine.  The TPL performs the same aggregation of the cancellation exceptions as PLINQ, as well, which is why a single exception handler for OperationCanceledException will cleanly handle this scenario.  This works because we’re using the same CancellationToken provided in the ParallelOptions.  If a different exception was thrown by one thread, or a CancellationToken from a different CancellationTokenSource was used to raise our exception, we would instead receive all of our individual exceptions merged into one AggregateException.

    Read the article

  • SQL SERVER – Extending SQL Azure with Azure worker role – Guest Post by Paras Doshi

    - by pinaldave
    This is guest post by Paras Doshi. Paras Doshi is a research Intern at SolidQ.com and a Microsoft student partner. He is currently working in the domain of SQL Azure. SQL Azure is nothing but a SQL server in the cloud. SQL Azure provides benefits such as on demand rapid provisioning, cost-effective scalability, high availability and reduced management overhead. To see an introduction on SQL Azure, check out the post by Pinal here In this article, we are going to discuss how to extend SQL Azure with the Azure worker role. In other words, we will attempt to write a custom code and host it in the Azure worker role; the aim is to add some features that are not available with SQL Azure currently or features that need to be customized for flexibility. This way we extend the SQL Azure capability by building some solutions that run on Azure as worker roles. To understand Azure worker role, think of it as a windows service in cloud. Azure worker role can perform background processes, and to handle processes such as synchronization and backup, it becomes our ideal tool. First, we will focus on writing a worker role code that synchronizes SQL Azure databases. Before we do so, let’s see some scenarios in which synchronization between SQL Azure databases is beneficial: scaling out access over multiple databases enables us to handle workload efficiently As of now, SQL Azure database can be hosted in one of any six datacenters. By synchronizing databases located in different data centers, one can extend the data by enabling access to geographically distributed data Let us see some scenarios in which SQL server to SQL Azure database synchronization is beneficial To backup SQL Azure database on local infrastructure Rather than investing in local infrastructure for increased workloads, such workloads could be handled by cloud Ability to extend data to different datacenters located across the world to enable efficient data access from remote locations Now, let us develop cloud-based app that synchronizes SQL Azure databases. For an Introduction to developing cloud based apps, click here Now, in this article, I aim to provide a bird’s eye view of how a code that synchronizes SQL Azure databases look like and then list resources that can help you develop the solution from scratch. Now, if you newly add a worker role to the cloud-based project, this is how the code will look like. (Note: I have added comments to the skeleton code to point out the modifications that will be required in the code to carry out the SQL Azure synchronization. Note the placement of Setup() and Sync() function.) Click here (http://parasdoshi1989.files.wordpress.com/2011/06/code-snippet-1-for-extending-sql-azure-with-azure-worker-role1.pdf ) Enabling SQL Azure databases synchronization through sync framework is a two-step process. In the first step, the database is provisioned and sync framework creates tracking tables, stored procedures, triggers, and tables to store metadata to enable synchronization. This is one time step. The code for the same is put in the setup() function which is called once when the worker role starts. Now, the second step is continuous (or on demand) synchronization of SQL Azure databases by propagating changes between databases. This is done on a continuous basis by calling the sync() function in the while loop. The code logic to synchronize changes between SQL Azure databases should be put in the sync() function. Discussing the coding part step by step is out of the scope of this article. Therefore, let me suggest you a resource, which is given here. Also, note that before you start developing the code, you will need to install SYNC framework 2.1 SDK (download here). Further, you will reference some libraries before you start coding. Details regarding the same are available in the article that I just pointed to. You will be charged for data transfers if the databases are not in the same datacenter. For pricing information, go here Currently, a tool named DATA SYNC, which is built on top of sync framework, is available in CTP that allows SQL Azure <-> SQL server and SQL Azure <-> SQL Azure synchronization (without writing single line of code); however, in some cases, the custom code shown in this blogpost provides flexibility that is not available with Data SYNC. For instance, filtering is not supported in the SQL Azure DATA SYNC CTP2; if you wish to have such a functionality now, then you have the option of developing a custom code using SYNC Framework. Now, this code can be easily extended to synchronize at some schedule. Let us say we want the databases to get synchronized every day at 10:00 pm. This is what the code will look like now: (http://parasdoshi1989.files.wordpress.com/2011/06/code-snippet-2-for-extending-sql-azure-with-azure-worker-role.pdf) Don’t you think that by writing such a code, we are imitating the functionality provided by the SQL server agent for a SQL server? Think about it. We are scheduling our administrative task by writing custom code – in other words, we have developed a “Light weight SQL server agent for SQL Azure!” Since the SQL server agent is not currently available in cloud, we have developed a solution that enables us to schedule tasks, and thus we have extended SQL Azure with the Azure worker role! Now if you wish to track jobs, you can do so by storing this data in SQL Azure (or Azure tables). The reason is that Windows Azure is a stateless platform, and we will need to store the state of the job ourselves and the choice that you have is SQL Azure or Azure tables. Note that this solution requires custom code and also it is not UI driven; however, for now, it can act as a temporary solution until SQL server agent is made available in the cloud. Moreover, this solution does not encompass functionalities that a SQL server agent provides, but it does open up an interesting avenue to schedule some of the tasks such as backup and synchronization of SQL Azure databases by writing some custom code in the Azure worker role. Now, let us see one more possibility – i.e., running BCP through a worker role in Azure-hosted services and then uploading the backup files either locally or on blobs. If you upload it locally, then consider the data transfer cost. If you upload it to blobs residing in the same datacenter, then no transfer cost applies but the cost on blob size applies. So, before choosing the option, you need to evaluate your preferences keeping the cost associated with each option in mind. In this article, I have shown that Azure worker role solution could be developed to synchronize SQL Azure databases. Moreover, a light-weight SQL server agent for SQL Azure can be developed. Also we discussed the possibility of running BCP through a worker role in Azure-hosted services for backing up our precious SQL Azure data. Thus, we can extend SQL Azure with the Azure worker role. But remember: you will be charged for running Azure worker roles. So at the end of the day, you need to ask – am I willing to build a custom code and pay money to achieve this functionality? I hope you found this blog post interesting. If you have any questions/feedback, you can comment below or you can mail me at Paras[at]student-partners[dot]com Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Azure, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • Life Technologies: Making Life Easier to Manage

    - by Michael Snow
    12.00 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} When we’re thinking about customer engagement, we’re acutely aware of all the forces at play competing for our customer’s attention. Solutions that make life easier for our customers draw attention to themselves. We tend to engage more when there is a distinct benefit and we can take a deep breath and accept that there is hope in the world and everything isn’t designed to frustrate us and make our lives miserable. (sigh…) When products are designed to automate processes that were consuming hours of our time with no relief in sight, they deserve to be recognized. One of our recent Oracle Fusion Middleware Innovation Award Winners in the WebCenter category, Life Technologies, has recently posted a video promoting their “award winning” solution. The Oracle Innovation Awards are part of the overall Oracle Excellence awards given to customers for innovation with Oracle products. More info here. Their award nomination included this description: Life Technologies delivered the My Life Service Portal as part of a larger Digital Hub strategy. This Portal is the first of its kind in the biotechnology service providing industry. The Portal provides access to Life Technologies cloud based service monitoring system where all customer deployed instruments can be remotely monitored and proactively repaired. The portal provides alerts from these cloud based monitoring services directly to the customer and to Life Technologies Field Engineers. The Portal provides insight into the instruments and services customers purchased for the purpose of analyzing and anticipating future customer needs and creating targeted sales and service programs. This portal not only provides benefits for Life Technologies internal sales and service teams but provides customers a central place to track all pertinent instrument information including: instrument service history instrument status and previous activities instrument performance analytics planned service visits warranty/contract information discussion forums social networks for lab management and collaboration alerts and notifications on all of the above team scheduling for instrument usage promote optional reagents required to keep instruments performing From their website The Life Technologies Instruments & Services Portal Helps You Save Time and Gain Peace of Mind Introducing the new, award-winning, free online tool that enables easier management of your instrument use and care, faster response to requests for service or service quotes, and instant sharing of key instrument and service information with your colleagues. Now – this unto itself is obviously beneficial for their customers who were previously burdened with having to do all of these tasks separately, manually and inconsistently by nature. Now – all in one place and free to their customers – a portal that ties it all together. They now have built the platform to give their customers yet another reason to do business with them – Their headline on their product page says it all: “Life is now easier to manage - All your instrument use and care in one place – the no-cost, no-hassle Instruments and Services Portal.” Of course – it’s very convenient that the company name includes “Life” and now can also promote to their clients and prospects that doing business with them is easy and their sophisticated lab equipment is easy to manage. In an industry full of PhD’s – “Easy” isn’t usually the first word that comes to mind, but Life Technologies has now tied the word to their brand in a very eloquent way. Between our work lives and family or personal lives, getting any mono-focused minutes of dedicated attention has become such a rare occurrence in our current era of multi-tasking that those moments of focus are highly prized. So – when something is done really well – so well that it becomes captivating and urges sharing impulses – I take notice and dig deeper and most of the time I discover other gems not so hidden below the surface. And then I share with those I know would enjoy and understand. In the spirit of full disclosure, I must admit here that the first person I shared the videos below with was my daughter. She’s in her senior year of high school in the midst of her college search. She’s passionate about her academics and has already decided that she wants to study Neuroscience in college and like her mother will be in for the long haul to a PhD eventually. In a summer science program at Smith College 2 summers ago – she sent the family famous text to me – “I just dissected a sheep’s brain – wicked cool!” – This was followed by an equally memorable text this past summer in a research mentorship in Neuroscience at UConn – “Just sliced up some rat brain. Reminded me of a deli slicer at the supermarket… sorry I forgot to call last night…” So… needless to say – I knew I had an audience that would enjoy and understand these videos below and are now being shared among her science classmates and faculty. And evidently - so does Life Technologies! They’ve done a great job on these making them fun and something that will easily be shared among their customers social networks. They’ve created a neuro-archetypal character, “Ph.Diddy” and know that their world of clients in academics, research, and other institutions would understand and enjoy the “edutainment” value in this series of videos on their YouTube channel that pokes fun at the stereotypes while also promoting their products at the same time. They use their Facebook page for additional engagement with their clients and as another venue to promote these videos. Enjoy this one as well! More to be found here: http://www.youtube.com/lifetechnologies Stay tuned to this Oracle WebCenter blog channel. Tomorrow we'll be taking a look at another winner of the Innovation Awards, LADWP - helping to keep the citizens of Los Angeles engaged with their Water and Power provider.

    Read the article

  • Product Development Investment: A Measure of Vendor Performance

    - by Jim Mcglothlin
    The relationship between a large, complex organization and its key suppliers of information technology is normally more than just "strategic". Expectations about the duration of the relationship typically exceed 20 years. Enterprise applications and technology infrastructure are not expected to be changed out like petunias. So how would you rate the due diligence processes as performed in Higher Education when selecting critical, transformational information technology? My observation: I see a lot of effort put into elaborate demonstration of basic software functionality. I see a lot of attention paid to the cost element of technology acquisition, including the contracted cost of implementation consulting services. But the factor that receives only cursory analysis and due diligence is long-term performance--the ability of a vendor to grow, expand, and develop, and bring its customers along with it. So what should you look for in a long-term IT supplier? Oracle has a public track record for product development. The annual investment has been on a run rate of almost $3 Billion organic product development. Oracle's well-publicized acquisitions and mergers have been supplemental to its R&D. This is important for Higher Education. Another meaningful way to evaluate a company is to look at the tangible track record of enhancement. Consider the Oracle-PeopleSoft enterprise business platform since acquired by Oracle 6 years ago: Product or Technology Enhancement Customer or User Impact Service Oriented Architecture (SOA) 300+ new web services delivered in versions 9.0 & 9.1 provide flexibility, so that customers can integrate PeopleSoft with other applications. Campus Solutions has added Admissions and Constituent Web Services. Constituent Relationship Management PeopleSoft CRM 9.1 for Higher Education introduced new process flows for student recruiting and retention to support "Student Success" initiatives. A 360 view of the constituent is now delivered, and the concept of a single-stop Student Services Center is now in CRM 9.1 with tight integration to PeopleSoft Campus Solutions. Human Capital Management Contract Pay for Education, with flexibility for configuration and calculation, has been extended in HCM 9.1. New chartfield integration among Project Costing - Time & Labor - Payroll to serve the labor distribution requirements for Grants / Sponsored Research. Talent Management PeopleSoft 9.0 and 9.1 feature an integrated talent management approach centered on definitions in "Profile Manager", with all new usability improvements. Internal and external candidate pools, and the entire recruitment process, are driven by delivered configurable selection and on-boarding processes. Interview scheduling, and online job offers are newly delivered processes. Performance Management PeopleSoft HCM ePerformance 9.1 will include significant new functionality designed to help organizations more effectively align business objectives with employee goals. Using an Organization Chart view, your business goals can flow down to become tangible objectives per employee. Succession Planning / Workforce Development New in HCM 9.0, enhanced in 9.1, is a planning capability for regular or unusual (major organizational change) succession of internal or external candidates. PeopleSoft supports employee-based career planning, which ultimately increases the integrity of the succession planning process (identify their career needs, plans, preferences, and interests). Dashboards / Oracle Business Intelligence Application Suite Oracle Human Resources Analytics provides the workforce information foundation that integrates data from HR functional areas and Finance. Oracle Human Resources Analytics delivers 9 dashboards and over 200 reports. Provide your HR professionals and front-line managers the tools to analyze workforce staffing, retention, productivity, to better source high-quality applicants, and to reduce absence costs. Multi-year Planning and Commitment Control External funding sources, especially Grants, require a multi-year encumbrance business process. PeopleSoft HCM 9.1 adds multi-year funding and commitment control, including budget checking. The newly designed Real Time Budget Checking will provide the customer with an updated snapshot of their budget and encumbrances at any given time. Position Budgeting with Hyperion Hyperion Planning world-class products now include delivered integration to PeopleSoft HCM. Position Budgeting is available in the new Public Sector Planning module of Hyperion. Web 2.0 features for the latest in usability PeopleSoft 9.1 features a contemporary internet user experience: Partial-page refreshing Drag and drop pagelets New menu structure Navigation pagelets Modal popup message windows Favorites & recently used links Type-ahead Drag and drop grid columns, pop-out grids Portal Workspaces Enterprise 2.0 for your collaborative web communities, using new content management, along with Wikis, blogs, and discussion forums in PeopleSoft Portal 9.1. PeopleTools enhanced by Oracle Fusion Middleware Standards-based tools have been added to the PeopleTools application infrastructure: BI (XML) Publisher, Java tools. Certified for use with PeopleSoft: Oracle Business Intelligence (OBIEE), Oracle Enterprise Manager, Oracle Weblogic Server, Oracle SOA Suite. Hosting for PeopleSoft applications A solid new deployment option: Oracle On Demand remote hosting center for high scalability, security, and continuity of operations. Business Process Outsourcing (BPO) for HCM / Payroll functions Partnership with AT&T provides hosting of HR/Payroll application along with payroll business process operations, and subscription-based service fees (SaaS). AT&T BPO full service includes pay sheet processing, bank and 3rd party file transfer, payroll tax handling, etc. Continuous Delivery Model Feature Packs provide faster time-to-benefit; new features become available in PeopleSoft 9.1 (or Campus Solutions 9.0) without need to perform upgrade. Golden person data model across all campus applications Oracle Higher Education Constituent Hub provides synchronization and data governance of person data across any application, e.g. HR/ Payroll, Student Information System, Housing, Emergency Contact, LMS, CRM. Oracle's aggressive enhancement plans within the "Applications Unlimited" program continue, as new functionality is under development for a new version of a PeopleSoft release planned for 2012. Meanwhile, new capabilities are planned on an annual basis in Feature Packs. PeopleSoft just delivered the HCM 2010 Feature Pack and another is planned for 2011. In February we plan to have over 100 customers from our Customer Advisory Boards at our PeopleSoft Development Center in California to review designs for all of these releases. For those of you near New York City The investment and progressive development story described above is the subject of an Oracle road show event on February 9, 2011. Charting Your Course with Oracle Applications is a global event series designed to help business and IT executives assess the impact of new inflection points on their business and applications roadmap: changing workforces, shifting customer and constituent bases, and increased volatility. Learn how innovations ranging from new deployment models like cloud computing to the introduction of social applications and smart devices are delivering results across all areas of business and industry. THIS DOCUMENT IS FOR INFORMATIONAL PURPOSES ONLY AND MAY NOT BE INCORPORATED INTO A CONTRACT OR AGREEMENT.

    Read the article

  • OS Analytics - Deep Dive Into Your OS

    - by Eran_Steiner
    Enterprise Manager Ops Center provides a feature called "OS Analytics". This feature allows you to get a better understanding of how the Operating System is being utilized. You can research the historical usage as well as real time data. This post will show how you can benefit from OS Analytics and how it works behind the scenes. We will have a call to discuss this blog - please join us!Date: Thursday, November 1, 2012Time: 11:00 am, Eastern Daylight Time (New York, GMT-04:00)1. Go to https://oracleconferencing.webex.com/oracleconferencing/j.php?ED=209833067&UID=1512092402&PW=NY2JhMmFjMmFh&RT=MiMxMQ%3D%3D2. If requested, enter your name and email address.3. If a password is required, enter the meeting password: oracle1234. Click "Join". To join the teleconference:Call-in toll-free number:       1-866-682-4770  (US/Canada)      Other countries:                https://oracle.intercallonline.com/portlets/scheduling/viewNumbers/viewNumber.do?ownerNumber=5931260&audioType=RP&viewGa=true&ga=ONConference Code:       7629343#Security code:            7777# Here is quick summary of what you can do with OS Analytics in Ops Center: View historical charts and real time value of CPU, memory, network and disk utilization Find the top CPU and Memory processes in real time or at a certain historical day Determine proper monitoring thresholds based on historical data View Solaris services status details Drill down into a process details View the busiest zones if applicable Where to start To start with OS Analytics, choose the OS asset in the tree and click the Analytics tab. You can see the CPU utilization, Memory utilization and Network utilization, along with the current real time top 5 processes in each category (click the image to see a larger version):  In the above screen, you can click each of the top 5 processes to see a more detailed view of that process. Here is an example of one of the processes: One of the cool things is that you can see the process tree for this process along with some port binding and open file descriptors. On Solaris machines with zones, you get an extra level of tabs, allowing you to get more information on the different zones: This is a good way to see the busiest zones. For example, one zone may not take a lot of CPU but it can consume a lot of memory, or perhaps network bandwidth. To see the detailed Analytics for each of the zones, simply click each of the zones in the tree and go to its Analytics tab. Next, click the "Processes" tab to see real time information of all the processes on the machine: An interesting column is the "Target" column. If you configured Ops Center to work with Enterprise Manager Cloud Control, then the two products will talk to each other and Ops Center will display the correlated target from Cloud Control in this table. If you are only using Ops Center - this column will remain empty. Next, if you view a Solaris machine, you will have a "Services" tab: By default, all services will be displayed, but you can choose to display only certain states, for example, those in maintenance or the degraded ones. You can highlight a service and choose to view the details, where you can see the Dependencies, Dependents and also the location of the service log file (not shown in the picture as you need to scroll down to see the log file). The "Threshold" tab is particularly helpful - you can view historical trends of different monitored values and based on the graph - determine what the monitoring values should be: You can ask Ops Center to suggest monitoring levels based on the historical values or you can set your own. The different colors in the graph represent the current set levels: Red for critical, Yellow for warning and Blue for Information, allowing you to quickly see how they're positioned against real data. It's important to note that when looking at longer periods, Ops Center smooths out the data and uses averages. So when looking at values such as CPU Usage, try shorter time frames which are more detailed, such as one hour or one day. Applying new monitoring values When first applying new values to monitored attributes - a popup will come up asking if it's OK to get you out of the current Monitoring Policy. This is OK if you want to either have custom monitoring for a specific machine, or if you want to use this current machine as a "Gold image" and extract a Monitoring Policy from it. You can later apply the new Monitoring Policy to other machines and also set it as a default Monitoring Profile. Once you're done with applying the different monitoring values, you can review and change them in the "Monitoring" tab. You can also click the "Extract a Monitoring Policy" in the actions pane on the right to save all the new values to a new Monitoring Policy, which can then be found under "Plan Management" -> "Monitoring Policies". Visiting the past Under the "History" tab you can "go back in time". This is very helpful when you know that a machine was busy a few hours ago (perhaps in the middle of the night?), but you were not around to take a look at it in real time. Here's a view into yesterday's data on one of the machines: You can see an interesting CPU spike happening at around 3:30 am along with some memory use. In the bottom table you can see the top 5 CPU and Memory consumers at the requested time. Very quickly you can see that this spike is related to the Solaris 11 IPS repository synchronization process using the "pkgrecv" command. The "time machine" doesn't stop here - you can also view historical data to determine which of the zones was the busiest at a given time: Under the hood The data collected is stored on each of the agents under /var/opt/sun/xvm/analytics/historical/ An "os.zip" file exists for the main OS. Inside you will find many small text files, named after the Epoch time stamp in which they were taken If you have any zones, there will be a file called "guests.zip" containing the same small files for all the zones, as well as a folder with the name of the zone along with "os.zip" in it If this is the Enterprise Controller or the Proxy Controller, you will have folders called "proxy" and "sat" in which you will find the "os.zip" for that controller The actual script collecting the data can be viewed for debugging purposes as well: On Linux, the location is: /opt/sun/xvmoc/private/os_analytics/collect On Solaris, the location is /opt/SUNWxvmoc/private/os_analytics/collect If you would like to redirect all the standard error into a file for debugging, touch the following file and the output will go into it: # touch /tmp/.collect.stderr   The temporary data is collected under /var/opt/sun/xvm/analytics/.collectdb until it is zipped. If you would like to review the properties for the Analytics, you can view those per each agent in /opt/sun/n1gc/lib/XVM.properties. Find the section "Analytics configurable properties for OS and VSC" to view the Analytics specific values. I hope you find this helpful! Please post questions in the comments below. Eran Steiner

    Read the article

  • SQL SERVER – Faster SQL Server Databases and Applications – Power and Control with SafePeak Caching Options

    - by Pinal Dave
    Update: This blog post is written based on the SafePeak, which is available for free download. Today, I’d like to examine more closely one of my preferred technologies for accelerating SQL Server databases, SafePeak. Safepeak’s software provides a variety of advanced data caching options, techniques and tools to accelerate the performance and scalability of SQL Server databases and applications. I’d like to look more closely at some of these options, as some of these capabilities could help you address lagging database and performance on your systems. To better understand the available options, it is best to start by understanding the difference between the usual “Basic Caching” vs. SafePeak’s “Dynamic Caching”. Basic Caching Basic Caching (or the stale and static cache) is an ability to put the results from a query into cache for a certain period of time. It is based on TTL, or Time-to-live, and is designed to stay in cache no matter what happens to the data. For example, although the actual data can be modified due to DML commands (update/insert/delete), the cache will still hold the same obsolete query data. Meaning that with the Basic Caching is really static / stale cache.  As you can tell, this approach has its limitations. Dynamic Caching Dynamic Caching (or the non-stale cache) is an ability to put the results from a query into cache while maintaining the cache transaction awareness looking for possible data modifications. The modifications can come as a result of: DML commands (update/insert/delete), indirect modifications due to triggers on other tables, executions of stored procedures with internal DML commands complex cases of stored procedures with multiple levels of internal stored procedures logic. When data modification commands arrive, the caching system identifies the related cache items and evicts them from cache immediately. In the dynamic caching option the TTL setting still exists, although its importance is reduced, since the main factor for cache invalidation (or cache eviction) become the actual data updates commands. Now that we have a basic understanding of the differences between “basic” and “dynamic” caching, let’s dive in deeper. SafePeak: A comprehensive and versatile caching platform SafePeak comes with a wide range of caching options. Some of SafePeak’s caching options are automated, while others require manual configuration. Together they provide a complete solution for IT and Data managers to reach excellent performance acceleration and application scalability for  a wide range of business cases and applications. Automated caching of SQL Queries: Fully/semi-automated caching of all “read” SQL queries, containing any types of data, including Blobs, XMLs, Texts as well as all other standard data types. SafePeak automatically analyzes the incoming queries, categorizes them into SQL Patterns, identifying directly and indirectly accessed tables, views, functions and stored procedures; Automated caching of Stored Procedures: Fully or semi-automated caching of all read” stored procedures, including procedures with complex sub-procedure logic as well as procedures with complex dynamic SQL code. All procedures are analyzed in advance by SafePeak’s  Metadata-Learning process, their SQL schemas are parsed – resulting with a full understanding of the underlying code, objects dependencies (tables, views, functions, sub-procedures) enabling automated or semi-automated (manually review and activate by a mouse-click) cache activation, with full understanding of the transaction logic for cache real-time invalidation; Transaction aware cache: Automated cache awareness for SQL transactions (SQL and in-procs); Dynamic SQL Caching: Procedures with dynamic SQL are pre-parsed, enabling easy cache configuration, eliminating SQL Server load for parsing time and delivering high response time value even in most complicated use-cases; Fully Automated Caching: SQL Patterns (including SQL queries and stored procedures) that are categorized by SafePeak as “read and deterministic” are automatically activated for caching; Semi-Automated Caching: SQL Patterns categorized as “Read and Non deterministic” are patterns of SQL queries and stored procedures that contain reference to non-deterministic functions, like getdate(). Such SQL Patterns are reviewed by the SafePeak administrator and in usually most of them are activated manually for caching (point and click activation); Fully Dynamic Caching: Automated detection of all dependent tables in each SQL Pattern, with automated real-time eviction of the relevant cache items in the event of “write” commands (a DML or a stored procedure) to one of relevant tables. A default setting; Semi Dynamic Caching: A manual cache configuration option enabling reducing the sensitivity of specific SQL Patterns to “write” commands to certain tables/views. An optimization technique relevant for cases when the query data is either known to be static (like archive order details), or when the application sensitivity to fresh data is not critical and can be stale for short period of time (gaining better performance and reduced load); Scheduled Cache Eviction: A manual cache configuration option enabling scheduling SQL Pattern cache eviction based on certain time(s) during a day. A very useful optimization technique when (for example) certain SQL Patterns can be cached but are time sensitive. Example: “select customers that today is their birthday”, an SQL with getdate() function, which can and should be cached, but the data stays relevant only until 00:00 (midnight); Parsing Exceptions Management: Stored procedures that were not fully parsed by SafePeak (due to too complex dynamic SQL or unfamiliar syntax), are signed as “Dynamic Objects” with highest transaction safety settings (such as: Full global cache eviction, DDL Check = lock cache and check for schema changes, and more). The SafePeak solution points the user to the Dynamic Objects that are important for cache effectiveness, provides easy configuration interface, allowing you to improve cache hits and reduce cache global evictions. Usually this is the first configuration in a deployment; Overriding Settings of Stored Procedures: Override the settings of stored procedures (or other object types) for cache optimization. For example, in case a stored procedure SP1 has an “insert” into table T1, it will not be allowed to be cached. However, it is possible that T1 is just a “logging or instrumentation” table left by developers. By overriding the settings a user can allow caching of the problematic stored procedure; Advanced Cache Warm-Up: Creating an XML-based list of queries and stored procedure (with lists of parameters) for periodically automated pre-fetching and caching. An advanced tool allowing you to handle more rare but very performance sensitive queries pre-fetch them into cache allowing high performance for users’ data access; Configuration Driven by Deep SQL Analytics: All SQL queries are continuously logged and analyzed, providing users with deep SQL Analytics and Performance Monitoring. Reduce troubleshooting from days to minutes with database objects and SQL Patterns heat-map. The performance driven configuration helps you to focus on the most important settings that bring you the highest performance gains. Use of SafePeak SQL Analytics allows continuous performance monitoring and analysis, easy identification of bottlenecks of both real-time and historical data; Cloud Ready: Available for instant deployment on Amazon Web Services (AWS). As you can see, there are many options to configure SafePeak’s SQL Server database and application acceleration caching technology to best fit a lot of situations. If you’re not familiar with their technology, they offer free-trial software you can download that comes with a free “help session” to help get you started. You can access the free trial here. Also, SafePeak is available to use on Amazon Cloud. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

    Read the article

  • SQL SERVER – Core Concepts – Elasticity, Scalability and ACID Properties – Exploring NuoDB an Elastically Scalable Database System

    - by pinaldave
    I have been recently exploring Elasticity and Scalability attributes of databases. You can see that in my earlier blog posts about NuoDB where I wanted to look at Elasticity and Scalability concepts. The concepts are very interesting, and intriguing as well. I have discussed these concepts with my friend Joyti M and together we have come up with this interesting read. The goal of this article is to answer following simple questions What is Elasticity? What is Scalability? How ACID properties vary from NOSQL Concepts? What are the prevailing problems in the current database system architectures? Why is NuoDB  an innovative and welcome change in database paradigm? Elasticity This word’s original form is used in many different ways and honestly it does do a decent job in holding things together over the years as a person grows and contracts. Within the tech world, and specifically related to software systems (database, application servers), it has come to mean a few things - allow stretching of resources without reaching the breaking point (on demand). What are resources in this context? Resources are the usual suspects – RAM/CPU/IO/Bandwidth in the form of a container (a process or bunch of processes combined as modules). When it is about increasing resources the simplest idea which comes to mind is the addition of another container. Another container means adding a brand new physical node. When it is about adding a new node there are two questions which comes to mind. 1) Can we add another node to our software system? 2) If yes, does adding new node cause downtime for the system? Let us assume we have added new node, let us see what the new needs of the system are when a new node is added. Balancing incoming requests to multiple nodes Synchronization of a shared state across multiple nodes Identification of “downstate” and resolution action to bring it to “upstate” Well, adding a new node has its advantages as well. Here are few of the positive points Throughput can increase nearly horizontally across the node throughout the system Response times of application will increase as in-between layer interactions will be improved Now, Let us put the above concepts in the perspective of a Database. When we mention the term “running out of resources” or “application is bound to resources” the resources can be CPU, Memory or Bandwidth. The regular approach to “gain scalability” in the database is to look around for bottlenecks and increase the bottlenecked resource. When we have memory as a bottleneck we look at the data buffers, locks, query plans or indexes. After a point even this is not enough as there needs to be an efficient way of managing such large workload on a “single machine” across memory and CPU bound (right kind of scheduling)  workload. We next move on to either read/write separation of the workload or functionality-based sharing so that we still have control of the individual. But this requires lots of planning and change in client systems in terms of knowing where to go/update/read and for reporting applications to “aggregate the data” in an intelligent way. What we ideally need is an intelligent layer which allows us to do these things without us getting into managing, monitoring and distributing the workload. Scalability In the context of database/applications, scalability means three main things Ability to handle normal loads without pressure E.g. X users at the Y utilization of resources (CPU, Memory, Bandwidth) on the Z kind of hardware (4 processor, 32 GB machine with 15000 RPM SATA drives and 1 GHz Network switch) with T throughput Ability to scale up to expected peak load which is greater than normal load with acceptable response times Ability to provide acceptable response times across the system E.g. Response time in S milliseconds (or agreed upon unit of measure) – 90% of the time The Issue – Need of Scale In normal cases one can plan for the load testing to test out normal, peak, and stress scenarios to ensure specific hardware meets the needs. With help from Hardware and Software partners and best practices, bottlenecks can be identified and requisite resources added to the system. Unfortunately this vertical scale is expensive and difficult to achieve and most of the operational people need the ability to scale horizontally. This helps in getting better throughput as there are physical limits in terms of adding resources (Memory, CPU, Bandwidth and Storage) indefinitely. Today we have different options to achieve scalability: Read & Write Separation The idea here is to do actual writes to one store and configure slaves receiving the latest data with acceptable delays. Slaves can be used for balancing out reads. We can also explore functional separation or sharing as well. We can separate data operations by a specific identifier (e.g. region, year, month) and consolidate it for reporting purposes. For functional separation the major disadvantage is when schema changes or workload pattern changes. As the requirement grows one still needs to deal with scale need in manual ways by providing an abstraction in the middle tier code. Using NOSQL solutions The idea is to flatten out the structures in general to keep all values which are retrieved together at the same store and provide flexible schema. The issue with the stores is that they are compromising on mostly consistency (no ACID guarantees) and one has to use NON-SQL dialect to work with the store. The other major issue is about education with NOSQL solutions. Would one really want to make these compromises on the ability to connect and retrieve in simple SQL manner and learn other skill sets? Or for that matter give up on ACID guarantee and start dealing with consistency issues? Hybrid Deployment – Mac, Linux, Cloud, and Windows One of the challenges today that we see across On-premise vs Cloud infrastructure is a difference in abilities. Take for example SQL Azure – it is wonderful in its concepts of throttling (as it is shared deployment) of resources and ability to scale using federation. However, the same abilities are not available on premise. This is not a mistake, mind you – but a compromise of the sweet spot of workloads, customer requirements and operational SLAs which can be supported by the team. In today’s world it is imperative that databases are available across operating systems – which are a commodity and used by developers of all hues. An Ideal Database Ability List A system which allows a linear scale of the system (increase in throughput with reasonable response time) with the addition of resources A system which does not compromise on the ACID guarantees and require developers to learn new paradigms A system which does not force fit a new way interacting with database by learning Non-SQL dialect A system which does not force fit its mechanisms for providing availability across its various modules. Well NuoDB is the first database which has all of the above abilities and much more. In future articles I will cover my hands-on experience with it. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: NuoDB

    Read the article

  • RiverTrail - JavaScript GPPGU Data Parallelism

    - by JoshReuben
    Where is WebCL ? The Khronos WebCL working group is working on a JavaScript binding to the OpenCL standard so that HTML 5 compliant browsers can host GPGPU web apps – e.g. for image processing or physics for WebGL games - http://www.khronos.org/webcl/ . While Nokia & Samsung have some protype WebCL APIs, Intel has one-upped them with a higher level of abstraction: RiverTrail. Intro to RiverTrail Intel Labs JavaScript RiverTrail provides GPU accelerated SIMD data-parallelism in web applications via a familiar JavaScript programming paradigm. It extends JavaScript with simple deterministic data-parallel constructs that are translated at runtime into a low-level hardware abstraction layer. With its high-level JS API, programmers do not have to learn a new language or explicitly manage threads, orchestrate shared data synchronization or scheduling. It has been proposed as a draft specification to ECMA a (known as ECMA strawman). RiverTrail runs in all popular browsers (except I.E. of course). To get started, download a prebuilt version https://github.com/downloads/RiverTrail/RiverTrail/rivertrail-0.17.xpi , install Intel's OpenCL SDK http://www.intel.com/go/opencl and try out the interactive River Trail shell http://rivertrail.github.com/interactive For a video overview, see  http://www.youtube.com/watch?v=jueg6zB5XaM . ParallelArray the ParallelArray type is the central component of this API & is a JS object that contains ordered collections of scalars – i.e. multidimensional uniform arrays. A shape property describes the dimensionality and size– e.g. a 2D RGBA image will have shape [height, width, 4]. ParallelArrays are immutable & fluent – they are manipulated by invoking methods on them which produce new ParallelArray objects. ParallelArray supports several constructors over arrays, functions & even the canvas. // Create an empty Parallel Array var pa = new ParallelArray(); // pa0 = <>   // Create a ParallelArray out of a nested JS array. // Note that the inner arrays are also ParallelArrays var pa = new ParallelArray([ [0,1], [2,3], [4,5] ]); // pa1 = <<0,1>, <2,3>, <4.5>>   // Create a two-dimensional ParallelArray with shape [3, 2] using the comprehension constructor var pa = new ParallelArray([3, 2], function(iv){return iv[0] * iv[1];}); // pa7 = <<0,0>, <0,1>, <0,2>>   // Create a ParallelArray from canvas.  This creates a PA with shape [w, h, 4], var pa = new ParallelArray(canvas); // pa8 = CanvasPixelArray   ParallelArray exposes fluent API functions that take an elemental JS function for data manipulation: map, combine, scan, filter, and scatter that return a new ParallelArray. Other functions are scalar - reduce  returns a scalar value & get returns the value located at a given index. The onus is on the developer to ensure that the elemental function does not defeat data parallelization optimization (avoid global var manipulation, recursion). For reduce & scan, order is not guaranteed - the onus is on the dev to provide an elemental function that is commutative and associative so that scan will be deterministic – E.g. Sum is associative, but Avg is not. map Applies a provided elemental function to each element of the source array and stores the result in the corresponding position in the result array. The map method is shape preserving & index free - can not inspect neighboring values. // Adding one to each element. var source = new ParallelArray([1,2,3,4,5]); var plusOne = source.map(function inc(v) {     return v+1; }); //<2,3,4,5,6> combine Combine is similar to map, except an index is provided. This allows elemental functions to access elements from the source array relative to the one at the current index position. While the map method operates on the outermost dimension only, combine, can choose how deep to traverse - it provides a depth argument to specify the number of dimensions it iterates over. The elemental function of combine accesses the source array & the current index within it - element is computed by calling the get method of the source ParallelArray object with index i as argument. It requires more code but is more expressive. var source = new ParallelArray([1,2,3,4,5]); var plusOne = source.combine(function inc(i) { return this.get(i)+1; }); reduce reduces the elements from an array to a single scalar result – e.g. Sum. // Calculate the sum of the elements var source = new ParallelArray([1,2,3,4,5]); var sum = source.reduce(function plus(a,b) { return a+b; }); scan Like reduce, but stores the intermediate results – return a ParallelArray whose ith elements is the results of using the elemental function to reduce the elements between 0 and I in the original ParallelArray. // do a partial sum var source = new ParallelArray([1,2,3,4,5]); var psum = source.scan(function plus(a,b) { return a+b; }); //<1, 3, 6, 10, 15> scatter a reordering function - specify for a certain source index where it should be stored in the result array. An optional conflict function can prevent an exception if two source values are assigned the same position of the result: var source = new ParallelArray([1,2,3,4,5]); var reorder = source.scatter([4,0,3,1,2]); // <2, 4, 5, 3, 1> // if there is a conflict use the max. use 33 as a default value. var reorder = source.scatter([4,0,3,4,2], 33, function max(a, b) {return a>b?a:b; }); //<2, 33, 5, 3, 4> filter // filter out values that are not even var source = new ParallelArray([1,2,3,4,5]); var even = source.filter(function even(iv) { return (this.get(iv) % 2) == 0; }); // <2,4> Flatten used to collapse the outer dimensions of an array into a single dimension. pa = new ParallelArray([ [1,2], [3,4] ]); // <<1,2>,<3,4>> pa.flatten(); // <1,2,3,4> Partition used to restore the original shape of the array. var pa = new ParallelArray([1,2,3,4]); // <1,2,3,4> pa.partition(2); // <<1,2>,<3,4>> Get return value found at the indices or undefined if no such value exists. var pa = new ParallelArray([0,1,2,3,4], [10,11,12,13,14], [20,21,22,23,24]) pa.get([1,1]); // 11 pa.get([1]); // <10,11,12,13,14>

    Read the article

  • parallel_for_each from amp.h – part 1

    - by Daniel Moth
    This posts assumes that you've read my other C++ AMP posts on index<N> and extent<N>, as well as about the restrict modifier. It also assumes you are familiar with C++ lambdas (if not, follow my links to C++ documentation). Basic structure and parameters Now we are ready for part 1 of the description of the new overload for the concurrency::parallel_for_each function. The basic new parallel_for_each method signature returns void and accepts two parameters: a grid<N> (think of it as an alias to extent) a restrict(direct3d) lambda, whose signature is such that it returns void and accepts an index of the same rank as the grid So it looks something like this (with generous returns for more palatable formatting) assuming we are dealing with a 2-dimensional space: // some_code_A parallel_for_each( g, // g is of type grid<2> [ ](index<2> idx) restrict(direct3d) { // kernel code } ); // some_code_B The parallel_for_each will execute the body of the lambda (which must have the restrict modifier), on the GPU. We also call the lambda body the "kernel". The kernel will be executed multiple times, once per scheduled GPU thread. The only difference in each execution is the value of the index object (aka as the GPU thread ID in this context) that gets passed to your kernel code. The number of GPU threads (and the values of each index) is determined by the grid object you pass, as described next. You know that grid is simply a wrapper on extent. In this context, one way to think about it is that the extent generates a number of index objects. So for the example above, if your grid was setup by some_code_A as follows: extent<2> e(2,3); grid<2> g(e); ...then given that: e.size()==6, e[0]==2, and e[1]=3 ...the six index<2> objects it generates (and hence the values that your lambda would receive) are:    (0,0) (1,0) (0,1) (1,1) (0,2) (1,2) So what the above means is that the lambda body with the algorithm that you wrote will get executed 6 times and the index<2> object you receive each time will have one of the values just listed above (of course, each one will only appear once, the order is indeterminate, and they are likely to call your code at the same exact time). Obviously, in real GPU programming, you'd typically be scheduling thousands if not millions of threads, not just 6. If you've been following along you should be thinking: "that is all fine and makes sense, but what can I do in the kernel since I passed nothing else meaningful to it, and it is not returning any values out to me?" Passing data in and out It is a good question, and in data parallel algorithms indeed you typically want to pass some data in, perform some operation, and then typically return some results out. The way you pass data into the kernel, is by capturing variables in the lambda (again, if you are not familiar with them, follow the links about C++ lambdas), and the way you use data after the kernel is done executing is simply by using those same variables. In the example above, the lambda was written in a fairly useless way with an empty capture list: [ ](index<2> idx) restrict(direct3d), where the empty square brackets means that no variables were captured. If instead I write it like this [&](index<2> idx) restrict(direct3d), then all variables in the some_code_A region are made available to the lambda by reference, but as soon as I try to use any of those variables in the lambda, I will receive a compiler error. This has to do with one of the direct3d restrictions, where only one type can be capture by reference: objects of the new concurrency::array class that I'll introduce in the next post (suffice for now to think of it as a container of data). If I write the lambda line like this [=](index<2> idx) restrict(direct3d), all variables in the some_code_A region are made available to the lambda by value. This works for some types (e.g. an integer), but not for all, as per the restrictions for direct3d. In particular, no useful data classes work except for one new type we introduce with C++ AMP: objects of the new concurrency::array_view class, that I'll introduce in the post after next. Also note that if you capture some variable by value, you could use it as input to your algorithm, but you wouldn’t be able to observe changes to it after the parallel_for_each call (e.g. in some_code_B region since it was passed by value) – the exception to this rule is the array_view since (as we'll see in a future post) it is a wrapper for data, not a container. Finally, for completeness, you can write your lambda, e.g. like this [av, &ar](index<2> idx) restrict(direct3d) where av is a variable of type array_view and ar is a variable of type array - the point being you can be very specific about what variables you capture and how. So it looks like from a large data perspective you can only capture array and array_view objects in the lambda (that is how you pass data to your kernel) and then use the many threads that call your code (each with a unique index) to perform some operation. You can also capture some limited types by value, as input only. When the last thread completes execution of your lambda, the data in the array_view or array are ready to be used in the some_code_B region. We'll talk more about all this in future posts… (a)synchronous Please note that the parallel_for_each executes as if synchronous to the calling code, but in reality, it is asynchronous. I.e. once the parallel_for_each call is made and the kernel has been passed to the runtime, the some_code_B region continues to execute immediately by the CPU thread, while in parallel the kernel is executed by the GPU threads. However, if you try to access the (array or array_view) data that you captured in the lambda in the some_code_B region, your code will block until the results become available. Hence the correct statement: the parallel_for_each is as-if synchronous in terms of visible side-effects, but asynchronous in reality.   That's all for now, we'll revisit the parallel_for_each description, once we introduce properly array and array_view – coming next. Comments about this post by Daniel Moth welcome at the original blog.

    Read the article

  • Feedback on meeting of the Linux User Group of Mauritius

    Once upon a time in a country far far away... Okay, actually it's not that bad but it has been a while since the last meeting of the Linux User Group of Mauritius (LUGM). There have been plans in the past but it never really happened. Finally, Selven took the opportunity and organised a new meetup with low administrative overhead, proper scheduling on alternative dates and a small attendee's survey on the preferred option. All the pre-work was nicely executed. First, I wasn't sure whether it would be possible to attend. Luckily I got some additional information, like children should come, too, and I was sold to this community gathering. According to other long-term members of the LUGM it was the first time 'ever' that a gathering was organised outside of Quatre Bornes, and I have to admit it was great! LUGM - user group meeting on the 15.06.2013 in L'Escalier Quick overview of Linux & the LUGM With a little bit of delay the LUGM meeting officially started with a quick overview and introduction to Linux presented by Avinash. During the session he told the audience that there had been quite some activity over the island some years ago but unfortunately it had been quiet during recent times. Of course, we also spoke about the acknowledged world dominance of Linux - thanks to Android - and the interesting possibilities for countries like Mauritius. It is known that a couple of public institutions have there back-end infrastructure running on Red Hat Linux systems but the presence on the desktop is still very low. Users are simply hanging on to Windows XP and older versions of Microsoft Office. Following the introduction of the LUGM Ajay joined into the session and it quickly changed into a panel discussion with lots of interesting questions and answers, sharing of first-hand experience either on the job or in private use of Linux, and a couple of ideas about how the LUGM could promote Linux a bit more in Mauritius. It was great to get an insight into other attendee's opinion and activities. Especially taking into consideration that I'm already using Linux since around 1996/97. Frankly speaking, I bought a SuSE 4.x distribution back in those days because I couldn't achieve certain tasks on Windows NT 4.0 without spending a fortune. OpenELEC Mediacenter Next, Selven gave us decent introduction on OpenELEC: Open Embedded Linux Entertainment Center (OpenELEC) is a small Linux distribution built from scratch as a platform to turn your computer into an XBMC media center. OpenELEC is designed to make your system boot fast, and the install is so easy that anyone can turn a blank PC into a media machine in less than 15 minutes. I didn't know about it until this presentation. In the past, I was mainly attached to Video Disk Recorder (VDR) as it allows the use of satellite receiver cards very easily. Hm, somehow I'm still missing my precious HTPC that I had to leave back in Germany years ago. It was great piece of hardware and software; self-built PC in a standard HiFi-sized (43cm) black desktop casing with 2 full-featured Hauppauge DVB-s cards, an old-fashioned Voodoo graphics card, WiFi card, Pioneer slot-in DVD drive, and fully remote controlled via infra-red thanks to Debian, VDR and LIRC. With EP Guide, scheduled recordings and general multimedia centre it offered all the necessary comfort in the living room, besides a Nintendo game console; actually a GameCube at that time... But I have to admit that putting OpenELEC on a Raspberry Pi would be a cool DIY project in the near future. LUGM - our next generation of linux users (15.06.2013) Project Evil Genius (PEG) Don't be scared of the paragraph header. Ish gave us a cool explanation why he named it PEG - Project Evil Genius; it's because of the time of the day when he was scripting down his ideas to be able to build, package and provide software applications to various Linux distributions. The main influence came from openSuSE but the platform didn't cater for his needs and ideas, so he started to work out something on his own. During his passionate session he also talked about the amazing experience he had due to other Linux users from all over the world. During the next couple of days Ish promised to put his script to GitHub... Looking forward to that. Check out Ish's personal blog over at hacklog.in. Highly recommended to read. Why India? Simply because the registration fees per year for an Indian domain are approximately 20 times less than for a Mauritian domain (.mu). Exploring the beach of L'Escalier af the meeting 'After-party' at the beach of L'Escalier Puh, after such interesting sessions, ideas around Linux and good conversation during the breaks and over lunch it was time for a little break-out. Selven suggested that we all should head down to the beach of L'Escalier and get some impressions of nature down here in the south of the island. Talking about 'beach' ;-) - absolutely not comparable to the white-sanded ones here in Flic en Flac... There are no lagoons down at the south coast of Mauriitus, and watching the breaking waves is a different experience and joy after all. Unfortunately, I was a little bit worried about the thoughtless littering at such a remote location. You have to drive on natural paths through the sugar cane fields and I was really shocked by the amount of rubbish lying around almost everywhere. Sad, really sad and it concurs with Yasir's recent article on the same topic. Resumé & outlook It was a great event. I met with new people, had some good conversations, and even my children enjoyed themselves the whole day. The location was well-chosen, enough space for each and everyone, parking spaces and even a playground for the children. Also, a big "Thank You" to Selven and his helpers for the organisation and preparation of lunch. I'm kind of sure that this was an exceptional meeting of LUGM and I'm really looking forward to the next gathering of Linux geeks. Hopefully, soon. All images are courtesy of Avinash Meetoo. More pictures are available on Flickr.

    Read the article

  • PASS: SQLRally Thoughts

    - by Bill Graziano
    The PASS Board recently decided that we wouldn’t put another US-based SQLRally on the calendar until we had a chance to review the program. I wanted to provide some of my thinking around this. Keep in mind that this is the opinion of one Board member. The Board committed to complete two SQLRally events to determine if an event modeled between SQL Saturday and the Summit was viable. We’ve completed the two events and now it’s time to step back and review the program. This is my seventh year on the PASS Board. Over that time people have asked me why PASS does certain things. Many, many times my answer has been “Because that’s the way we did it last year”. And I am tired of giving that answer. We need to take a step back and review the US-based SQLRally before we schedule another one. It would be irresponsible for me as a Board member to commit resources to this without validating that what we’re doing makes sense for the organization and our members. I have no doubt that this was a great event for the attendees. We just need to validate it’s the best use of our resources. Please keep in mind that we haven’t cancelled the event. We’ve just said we need to review it before scheduling another one. My opinion is that some fairly serious changes are needed to the model before we consider it again – IF we do it again. I’ve come to that conclusion after speaking with the Dallas organizers, our HQ team, our Marketing team, other Board members (including one of the Orlando organizers), attendees in Orlando and Dallas and visiting other similar events. I should point out that their views aren’t unanimous on nearly any part of this event -- which is one of the reasons I want to take some time and think about this before continuing. I think it’s helpful to look at the original goals of what we were trying to accomplish. Andy Warren wrote these up in August of 2010. My summary of these goals and some thoughts on each one is below. Many of these thoughts revolve around the growth of SQL Saturdays. In the two years since that document was written these events have grown significantly. The largest SQL Saturdays are now over 500 people which mean they are nearly the same size as our recent SQLRally. Our goals included: Geographic diversity. We wanted an event in an area of the country that was away from any given Summit location. I think that’s still a valid goal. But we also have SQL Saturdays all over the country. What does SQLRally bring to this that SQLSaturday doesn’t? Speaker growth. One of the stated goals was to build a “farm club” for speakers. This gives us a way for speakers to work up to speaking at Summit by speaking in front of larger crowds. What does SQLRally bring to this that the larger SQL Saturdays aren’t providing? Pre-Conference speakers is one obvious answer here. Lower price. On a per-day basis, SQLRally is roughly 1/4th the price of the Summit. We wanted a way for people to experience something Summit-like at a lower price point. The challenge is that we are very budget constrained at that lower price point. International Event Model.  (I need to write more about this but I’m out of time.  I’ll cover it in the next installment.) There are a number of things I really like about SQLRally. I love the smaller conferences. They give me a chance to meet more people than at something the size of Summit. I like the two day format. That gives you two evenings to be at social events with people. Seeing someone a second day is a great way to build a bond with that person. That’s more difficult to do at a SQL Saturday. We also need to talk about the financial aspects of the event. Last year generated a small $17,000 profit on revenues of $200,000. Percentage-wise that’s reasonable but on an absolute basis it’s not a huge amount in our budget. We think this year will lose between $30,000 and $50,000 and take roughly 1,000 hours of HQ time. We don’t have detailed financials back yet but that’s our best guess at this point. Part of that was driven by using a convention center instead of a hotel. Until we get detailed financials back we won’t have the full picture around the financial impact. This event also takes time and mindshare from our Marketing team. This may sound like a small thing but please don’t underestimate it. Our original vision for this was something that would take very little time from our Marketing team and just a few mentions in the Connector. It turned out to need more than that. And all those mentions and emails take up space we could use to talk about other events and other programs. Last I wanted to talk about some of the things I’m thinking about. I don’t think it’s as simple as saying if we just fix “X” it all gets better. Is this that much better of an event than SQL Saturdays? What if we gave a few SQL Saturdays some extra resources? When SQL Saturdays were around 250 people that wasn’t as viable. With some of those events over 500 we need to reconsider this. We need to get back to a hotel venue. That will help with cost and networking. Is this the best use of the 1,000 HQ hours that we invested in the event? Is our price-point correct? I’m leaning toward raising our price closer to Summit on a per-day basis. I think this will let us put on a higher quality event and alleviate much of the budget pressure. Should growing speakers be a focus? Having top-line pre-conference speakers helps market the event. It will also have an impact on pricing and overall profit. We should also ask if it actually does grow speakers. How many of these people will eventually register for Summit? Attend chapters? Is SQLRally a driver into PASS or is it something that chapters, etc. drive people to? Should we have one paid day and one free instead of two paid days? This is a very interesting model that is used by SQLBits in the UK. This gives you the two day aspect as well as offering options for paid and free attendees. I’m very intrigued by this. Should we focus on a topic? Buried in the minutes is a discussion of whether PASS should have a Business Analytics conference separate from Summit. This is an interesting question to consider. Would making SQLRally be focused on a particular topic make it more attractive? Would that even be a SQLRally? Can PASS effectively manage the two events? (FYI - Probably not.) Would it help differentiate it from Summit and SQL Saturday? These are all questions that I think should be asked and answered before we do this event again. And we can’t do that if we don’t take time to have the discussion. I wanted to get this published before I take off for a few days of vacation. When I get back I’d like to write more about why the international events are different and talk about where we go from here.

    Read the article

  • Remotely Schedule and Stream Recorded TV in Windows 7 Media Center

    - by DigitalGeekery
    Have you ever been away from home and suddenly realized you forgot to record your favorite program? Now Windows 7 Media Center, users can schedule recordings remotely from their phones or mobile devices with Remote Potato. How it Works Remote Potato installs server software on the host computer running Windows 7 Media Center. Once the software is installed, we’ll need to do some port forwarding on the router and setup an optional dynamic DNS address. When setup is completed, we will access the application through a web based interface. Silverlight is required for Streaming recorded TV, but scheduling recordings can be done through an HTML interface. Installing Remote Potato Download and install Remote Potato on the Media Center PC. (See download link below) If you plan to stream any Recorded TV, you’ll also want to install the streaming pack located on the same page. It isn’t required to stream all shows, only shows that require the AC3 audio codec. Click Yes to allow Remote Potato to add rules to the Windows Firewall for remote access. You’ll likely need to accept a few UAC prompts. When notified that the rules were added, click OK. Remote Potato will then prompt you to allow administrator privileges to reserve a URL for it’s web server. Click Yes. Remote Potato server will start. Click on the configuration button at the right to to reveal the settings tabs.   One the General tab, you’ll have the option to run Remote Potato on startup and minimized in the System Tray. If you’re running Media Center on a dedicated HTPC, you’ll probably want to enable both startup options. Forwarding Ports on Your Router You’ll need to forward a couple ports on your router. By default, these will be ports 9080 and 9081. In this example we’re using a Linksys WRT54GL router, however, the steps for port forwarding will vary from router to router. On the Linksys configuration page, click on the Applications & Gaming Tab, and then the Port Range Forward tab. Under Application, type in a name of your choosing. In both the Start and End boxes, type the port number 9080. Enter the local IP address of your Media Center computer in the IP address column. Click the check box under Enable. Repeat the process on the next line, but this time use port 9081. When finished, click the Save Settings button. Note: It’s highly recommended that you configure the home computer running Media Center & Remote Potato with a static IP address.   Find your IP Address You’ll need to find the IP address assigned to your router from your ISP. There are many ways to do this but a quick and easy way is to visit a site like checkip.dyndns.org (link available below) The current external IP address of your router will be displayed in the browser.   Dynamic DNS This is an optional step, but  it’s highly recommended. Many routers, such as the Linksys WRT54GL we are using, support Dynamic DNS (DDNS). What Dynamic DNS allows you to do is affiliate your home router’s external IP address to a domain name. Every time your home router is assigned a a new IP address by your ISP, the domain name is updated to point to your new IP address. Remote Potato’s user interface is accessed over the Internet is by connecting to your router’s IP address followed by a colon and the port number. (Ex: XXX.XXX.XXX.XXX:9080) Instead of constantly having to look up and remember an IP address, you can use DDNS along with a 3rd party provider like DynDNS.com, to sign up for a free domain name and configure it to be updated each time your router is assigned a new IP address. Go to the DynDNS.com website (See link at the end of the article) and sign up for a free Domain name. You’ll need to register and confirm by email.   Once you’ve signed in and selected your domain name click Activate Services. You’ll get a confirmation message that your domain name has been activated.    On the Linksys WRT54GL click on the Setup tab an then DDNS. Select DynDNS.org, or TZO.com if you prefer to use their service, from the drop down list.   With DynDNS, you’ll need to fill in your username and password you signed up with at the DynDNS website and the hostname you chose. Note: You can connect over your local network with the IP Address of the computer running Remote Potato followed by a colon and the port number. Ex: 192.168.1.2:9080 Logging in Remote Potato and Recording a Show Once you connect, you’ll see the start page. To view the TV listings, click on TV Guide. You’ll then see your guide listings. There are a few ways to navigate the listings. At the top left, you can click on any of the preset time buttons to jump to  the listings at that time of the day.  Click on the arrows to the right and left of the day and date at the top center to proceed to the previous or next day. Or, jump to a specific day with the date and date buttons at the top right.   To setup a recording, click on a program.   You can choose to record the individual show or the entire series by clicking on Record Show or Record Series.   Remote Potato on Mobile Devices Perhaps the coolest feature of Remote Potato is the ability to schedule recording from your phone or mobile device. Note: For any devices or computers without Silverlight, you will be prompted to view the HTML page. Select Browse Listings. Select your program to record. In the Program Details, select Record Show to record the single episode or Record Series to record all instances of the series. You will then see a red dot on the program listing to indicate that the show is scheduled for recording.   Streaming Recorded TV Click on Recorded TV from the home screen to access your previously recorded TV programs. Click on the selection you wish to stream. Click on Play. If you receive this error message, you’ll need to install the streaming pack for Remote Potato. This is found on the same download page as installation files. (See link below) The Begin from slider allows you to start playback from the start (by default) or a different time of the program by moving the slider. The Quality (bitrate) setting  allows you to choose the quality of the playback. We found the video quality on the Normal setting to be pretty lousy, and Low was just pointless. High was the best overall viewing experience as it provided smooth quality video playback. We experienced significant stuttering during playback using the Ultra High setting.   Click Start when you are ready to begin. When playback begins you’ll see a slider at the top right.   Move the slider left or right to increase or decrease the size of the video. There’s also a button to switch to full screen.   Media Center users who travel frequently or are always on the go will likely find Remote Potato to be a blessing. Since being released earlier this year, updates for Remote Potato have come fast and furious. The latest beta release includes support for streaming music and photos. If you like those nice network TV logos, check out our article on adding TV channel logos to Windows Media Center. Downloads and Links Download Remote Potato and Streaming Pack Find your IP address Sign Up for a Domain Name at DynDNS.com Similar Articles Productive Geek Tips Schedule Updates for Windows Media CenterUsing Netflix Watchnow in Windows Vista Media Center (Gmedia)Add a Sleep Timer to Windows 7 Media CenterStartup Customizations for Media Center in Windows 7Enable Media Streaming in Windows Home Server to Windows Media Player TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 FoxClocks adds World Times in your Statusbar (Firefox) Have Fun Editing Photo Editing with Citrify Outlook Connector Upgrade Error Gadfly is a cool Twitter/Silverlight app Enable DreamScene in Windows 7 Microsoft’s “How Do I ?” Videos

    Read the article

  • Silverlight 4 Training Kit

    - by ScottGu
    We recently released a new free Silverlight 4 Training Kit that walks you through building business applications with Silverlight 4.  You can browse the training kit online or alternatively download an entire offline version of the training kit.  The training material is structured on teaching how to use the new Silverlight 4 features to build an end to end business application. The training kit includes 8 modules, 25 videos, and several hands on labs. Below is a breakdown and links to all of the content. [In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu] Module 1: Introduction Click here to watch this module. In this video John Papa and Ian Griffiths discuss the key areas that the Building Business Applications with Silverlight 4 course focuses on. This module is the overview of the course and covers many key scenarios that are faced when building business applications, and how Silverlight can help address them. Module 2: WCF RIA Services Click here to explore this module. In this lab, you will create a web site for managing conferences that will be the basis for the other labs in this course. Don’t worry if you don’t complete a particular lab in the series – all lab manual instructions are accompanied by completed solutions, so you can either build your own solution from start to finish, or dive straight in at any point using the solutions provided as a starting point. In this lab you will learn how to set up WCF RIA Services, create bindings to the domain context, filter using the domain data source, and create domain service queries. Online Link Download Source Download Lab Document Videos Module 2.1 - WCF RIA Services Ian Griffiths sets up the Entity Framework and WCF RIA Services for the sample Event Manager application for the course. He covers how to set up the services, how the Domain Services work and the role that the DomainContext plays in the sample application. He also reviews the metadata classes and integrating the navigation framework. Module 2.2 – Using WCF RIA Services to Edit Entities Ian Griffiths discusses how he adds the ability to edit and create individual entities with the features built into WCF RIA Services into the sample Event Manager application. He covers data binding fundamentals, IQueryable, LINQ, the DomainDataSource, navigation to a single entity using the navigation framework, and how to use the Visual Studio designer to do much of the work . Module 2.3 – Showing Master/Details Records Using WCF RIA Services Ian Griffiths reviews how to display master/detail records for the sample Event Manager application using WCF RIA Services. He covers how to use the Include attribute to indicate which elements to serialize back to the client. Ian also demonstrates how to use the Data Sources window in the designer to add and bind controls to specific data elements. He wraps up by showing how to create custom services to the Domain Services. Module 3 – Authentication, Validation, MVVM, Commands, Implicit Styles and RichTextBox Click here to visit this module. This lab demonstrates how to build a login screen, integrate ASP.NET authentication, and perform validation on data elements. Model-View-ViewModel (MVVM) is introduced and used in this lab as a pattern to help separate the UI and business logic. You will also learn how to use implicit styling and the new RichTextBox control. Online Link Download Source Download Lab Document Videos Module 3.1 – Authentication Ian Griffiths covers how to integrate a login screen and authentication into the sample Event Manager application. Ian shows how to use the ASP.NET authentication and integrate it into WCF RIA Services and the Silverlight presentation layer. Module 3.2 – MVVM Ian Griffiths covers how to Model-View-ViewModel (MVVM) patterns into the sample Event Manager application. He discusses why MVVM exists, what separated presentation means, and why it is important. He shows how to connect the View to the ViewModel, why data binding is important in this symbiosis, and how everything fits together in the overall application. Module 3.3 –Validation Ian Griffiths discusses how validation of user input can be integrated into the sample Event Manager application. He demonstrates how to use the DataAnnotations, the INotifyDataErrorInfo interface, binding markup extensions, and WCF RIA Services in concert to achieve great validation in the sample application. He discusses how this technique allows for property level validation, entity level validation, and asynchronous server side validation. Module 3.4 – Implicit Styles Ian Griffiths discusses how why implicit styles are important and how they can be integrated into the sample Event Manager application. He shows how implicit styles defined in a resource dictionary can be applied to all elements of a particular kind throughout the application. Module 3.5 – RichTextBox Ian Griffiths discusses how the new RichTextBox control and it can be integrated into the sample Event Manager application. He demonstrates how the RichTextBox can provide editing for the event information and how it can display the rich text for selection and copying. Module 4 – User Profiles, Drop Targets, Webcam and Clipboard Click here to visit this module. This lab builds new features into the sample application to take the user's photo. It teaches you how to use the webcam to capture an image, use Silverlight as a drop target, and take advantage of programmatic access to the clipboard. Link Download Source Download Lab Document Videos Module 4.1 – Webcam Ian Griffiths demonstrates how the webcam adds value to the sample Event Manager application by capturing an image of the attendee. He discusses the VideoCaptureDevice, the CaptureDviceConfiguration, and the CaptureSource classes and how they allow audio and video to be captured so you can grab an image from the capture device and save it. Module 4.2 - Drag and Drop in Silverlight Ian Griffiths demonstrates how to capture and handle the Drop in the sample Event Manager application so the user can drag a photo from a file and drop it into the application. Ian reviews the AllowDrop property, the Drop event, how to access the file that can be dropped, and the other drag related events. He also reviews how to make this work across browsers and the challenges for this. Module 5 – Schedule Planner and Right Mouse Click Click here to visit this module. This lab builds on the application to allow grouping in the DataGrid and implement right mouse click features to add context menu support. Link Download Source Download Lab Document Videos Module 5.1 – Grouping and Binding Ian Griffiths demonstrates how to use the grouping features for data binding in the DataGrid and how it applies to the sample Event Manager application. He reviews the role of the CollectionViewSource in grouping, customizing the templates for headers, and how to work with grouping with ItemsControls. Module 5.2 – Layout Visual States Ian Griffiths demonstrates how to use the Fluid UI animation support for visual states in the ListBox control DataGrid and how it applies to the sample Event Manager application. He reviews the 3 visual states of BeforeLoaded, AfterLoaded, and BeforeUnloaded. Module 5.3 – Right Mouse Click Ian Griffiths demonstrates how to add support for handling the right mouse button click event to display a context menu for the Event Manager application. He demonstrates how to handle the event, show a custom context menu control, and integrate it into the scheduling portion of the application. Module 6 – Printing the Schedule Click here to visit this module. This lab teaches how to use the new printing features in Silverlight 4. The lab walks through the PrintDocument class and the ViewBox control, while showing how to print multiple pages of content using them. Link Download Source Download Lab Document Videos Module 6.1 – Printing and the Viewbox Ian Griffiths demonstrates how to add the ability to print the schedule to the sample Event Manager application. He walks through the importance of the PrintDocument class and its members. He also shows how to handle printing the visual tree and how the ViewBox control can help. Module 6.2 – Multi Page Printing Ian Griffiths expands on his printing discussion by showing how to handle printing multiple pages of content for the sample Event Manager application. He shows how to paginate the content and points out various tips to keep in mind when determining the printable area. Module 7 – Running the Event Dashboard Out of Browser Click here to visit this module. This lab builds a dashboard for the sample application while explaining the fundamentals of the out of browser features, how to handle authentication, displaying notifications (toasts), and how to use native integration to use COM Interop with Silverlight. Link Download Source Download Lab Document Videos Module 7.1 – Out of Browser Ian Griffiths discusses the role of an Out of Browser application for administrators to manage the events and users in the sample Event Manager application. He discusses several reasons why out of browser applications may better suit your needs including custom chrome, toasts, window placement, cross domain access, and file access. He demonstrates the basic technique to take your application and make it work out of browser using the tools. Module 7.2 – NotificationWindow (Toasts) for Elevated Trust Out of Browser Applications Ian Griffiths discusses the how toasts can be used in the sample Event Manager application to show information that may require the user's attention. Ian covers how to create a toast using the NotificationWindow, security implications, and how to make the toast appear as needed. Module 7.3 – Out of Browser Window Placement Ian Griffiths discusses the how to manage the window positioning when building an out of browser application, handling the windows state, and controlling and handling activation of the window. Module 7.4 – Out of Browser Elevated Trust Application Overview Ian Griffiths discusses the implications of creating trusted out of browser application for the Event Manager sample application. He reviews why you might want to use elevated trust, what features is opens to you, and how to take advantage of them. Topics Ian covers include the dynamic keyword in C# 4, the AutomationFactory class, the API to check if you are in a trusted application, and communicating with Excel. Module 8 – Advanced Out of Browser and MEF Click here to visit this module. This hands-on lab walks through the creation of a trusted out of browser application and the new functionality that comes with that. You will learn to use COM Automation, handle the window closing event, set custom window chrome, digitally sign your Silverlight out of browser trusted application, create a silent install option, and take advantage of MEF. Link Download Source Download Lab Document Videos Module 8.1 – Custom Window Chrome for Elevated Trust Out of Browser Applications Ian Griffiths discusses how to replace the standard operating system window chrome with customized chrome for an elevated trusted out of browser application. He covers how it is important to handle close, resize, minimize, and maximize events. Ian mentions that the tooling was not ready when he shot this video, but the good news is that the tooling now supports setting the custom chrome directly from the property page for the Silverlight application. Module 8.2 – Window Closing Event for Out of Browser Applications Ian Griffiths discusses the WindowClosing event and how to handle and optionally cancel the event. Module 8.3 – Silent Install of Out of Browser Applications Ian Griffiths discusses how to use the SLLauncher executable to install an out of browser application. He discusses the optional command line switches that can be set including how the emulate switch can help you emulate the install process. Ian also shows how to setup a shortcut for the application and tell the application where it should look for future updates online. Module 8.4 – Digitally Signing Out of Browser Application Ian Griffiths discusses how and why to digitally sign an out of browser application using the signtool program. He covers what trusted certificates are, the implications of signing (or not signing), and the effect on the user experience. Module 8.5 – The Value of MEF with Silverlight Ian Griffiths discusses what MEF is, how your application can benefit from it, and the fundamental features it puts at your disposal. He covers the 3 step import, export and compose process as well as how to dynamically import XAP files using MEF. Summary As you can probably tell from the long list above – this series contains a ton of great content, and hopefully provides a nice end-to-end walkthrough that helps explain how to take advantage of Silverlight 4 (and all its new features).  Hope this helps, Scott

    Read the article

  • SQL Server and Hyper-V Dynamic Memory Part 2

    - by SQLOS Team
    Part 1 of this series was an introduction and overview of Hyper-V Dynamic Memory. This part looks at SQL Server memory management and how the SQL engine responds to changing OS memory conditions.   Part 2: SQL Server Memory Management As with any Windows process, sqlserver.exe has a virtual address space (VAS) of 4GB on 32-bit and 8TB in 64-bit editions. Pages in its VAS are mapped to pages in physical memory when the memory is committed and referenced for the first time. The collection of VAS pages that have been recently referenced is known as the Working Set. How and when SQL Server allocates virtual memory and grows its working set depends on the memory model it uses. SQL Server supports three basic memory models:   1. Conventional Memory Model   The Conventional model is the default SQL Server memory model and has the following properties: - Dynamic - can grow or shrink its working set in response to load and external (operating system) memory conditions. - OS uses 4K pages – (not to be confused with SQL Server “pages” which are 8K regions of committed memory).- Pageable - Can be paged out to disk by the operating system.   2. Locked Page Model The locked page memory model is set when SQL Server is started with "Lock Pages in Memory" privilege*. It has the following characteristics: - Dynamic - can grow or shrink its working set in the same way as the Conventional model.- OS uses 4K pages - Non-Pageable – When memory is committed it is locked in memory, meaning that it will remain backed by physical memory and will not be paged out by the operating system. A common misconception is to interpret "locked" as non-dynamic. A SQL Server instance using the locked page memory model will grow and shrink (allocate memory and release memory) in response to changing workload and OS memory conditions in the same way as it does with the conventional model.   This is an important consideration when we look at Hyper-V Dynamic Memory – “locked” memory works perfectly well with “dynamic” memory.   * Note in “Denali” (Standard Edition and above), and in SQL 2008 R2 64-bit (Enterprise and above editions) the Lock Pages in Memory privilege is all that is required to set this model. In 2008 R2 64-Bit standard edition it also requires trace flag 845 to be set, in 2008 R2 32-bit editions it requires sp_configure 'awe enabled' 1.   3. Large Page Model The Large page model is set using trace flag 834 and potentially offers a small performance boost for systems that are configured with large pages. It is characterized by: - Static - memory is allocated at startup and does not change. - OS uses large (>2MB) pages - Non-Pageable The large page model is supported with Hyper-V Dynamic Memory (and Hyper-V also supports large pages), but you get no benefit from using Dynamic Memory with this model since SQL Server memory does not grow or shrink. The rest of this article will focus on the locked and conventional SQL Server memory models.   When does SQL Server grow? For “dynamic” configurations (Conventional and Locked memory models), the sqlservr.exe process grows – allocates and commits memory from the OS – in response to a workload. As much memory is allocated as is required to optimally run the query and buffer data for future queries, subject to limitations imposed by:   - SQL Server max server memory setting. If this configuration option is set, the buffer pool is not allowed to grow to more than this value. In SQL Server 2008 this value represents single page allocations, and in “Denali” it represents any size page allocations and also managed CLR procedure allocations.   - Memory signals from OS. The operating system sets a signal on memory resource notification objects to indicate whether it has memory available or whether it is low on available memory. If there is only 32MB free for every 4GB of memory a low memory signal is set, which continues until 64MB/4GB is free. If there is 96MB/4GB free the operating system sets a high memory signal. SQL Server only allocates memory when the high memory signal is set.   To summarize, for SQL Server to grow you need three conditions: a workload, max server memory setting higher than the current allocation, high memory signals from the OS.    When does SQL Server shrink caches? SQL Server as a rule does not like to return memory to the OS, but it will shrink its caches in response to memory pressure. Memory pressure can be divided into “internal” and “external”.   - External memory pressure occurs when the operating system is running low on memory and low memory signals are set. The SQL Server Resource Monitor checks for low memory signals approximately every 5 seconds and it will attempt to free memory until the signals stop.   To free memory SQL Server does the following: ·         Frees unused memory. ·         Notifies Memory Manager Clients to release memory o   Caches – Free unreferenced cache objects. o   Buffer pool - Based on oldest access times.   The freed memory is released back to the operating system. This process continues until the low memory resource notifications stop.    - Internal memory pressure occurs when the size of different caches and allocations increase but the SQL Server process needs to keep its total memory within a target value. For example if max server memory is set and certain caches are growing large, it will cause SQL to free memory for re-use internally, but not to release memory back to the OS. If you lower the value of max server memory you will generate internal memory pressure that will cause SQL to release memory back to the OS.    Memory pressure handling has not changed much since SQL 2005 and it was described in detail in a blog post by Slava Oks.   Note that SQL Server Express is an exception to the above behavior. Unlike other editions it does not assume it is the most important process running on the system but tries to be more “desktop” friendly. It will empty its working set after a period of inactivity.   How does SQL Server respond to changing OS memory?    In SQL Server 2005 support for Hot-Add memory was introduced. This feature, available in Enterprise and above editions, allows the server to make use of any extra physical memory that was added after SQL Server started. Being able to add physical memory when the system is running is limited to specialized hardware, but with the Hyper-V Dynamic Memory feature, when new memory is allocated to a guest virtual machine, it looks like hot-add physical memory to the guest. What this means is that thanks to the hot-add memory feature, SQL Server 2005 and higher can dynamically grow if more “physical” memory is granted to a guest VM by Hyper-V dynamic memory.   SQL Server checks OS memory every second and dynamically adjusts its “target” (based on available OS memory and max server memory) accordingly.   In “Denali” Standard Edition will also have sqlserver.exe support for hot-add memory when running virtualized (i.e. detecting and acting on Hyper-V Dynamic Memory allocations).   How does a SQL Server workload in a guest VM impact Hyper-V dynamic memory scheduling?   When a SQL workload causes the sqlserver.exe process to grow its working set, the Hyper-V memory scheduler will detect memory pressure in the guest VM and add memory to it. SQL Server will then detect the extra memory and grow according to workload demand. In our tests we have seen this feedback process cause a guest VM to grow quickly in response to SQL workload - we are still working on characterizing this ramp-up.    How does SQL Server respond when Hyper-V removes memory from a guest VM through ballooning?   If pressure from other VM's cause Hyper-V Dynamic Memory to take memory away from a VM through ballooning (allocating memory with a virtual device driver and returning it to the host OS), Windows Memory Manager will page out unlocked portions of memory and signal low resource notification events. When SQL Server detects these events it will shrink memory until the low memory notifications stop (see cache shrinking description above).    This raises another question. Can we make SQL Server release memory more readily and hence behave more "dynamically" without compromising performance? In certain circumstances where the application workload is predictable it may be possible to have a job which varies "max server memory" according to need, lowering it when the engine is inactive and raising it before a period of activity. This would have limited applicaability but it is something we're looking into.   What Memory Management changes are there in SQL Server “Denali”?   In SQL Server “Denali” (aka SQL11) the Memory Manager has been re-written to be more efficient. The main changes are summarized in this post. An important change with respect to Hyper-V Dynamic Memory support is that now the max server memory setting includes any size page allocations and managed CLR procedure allocations it now represents a closer approximation to total sqlserver.exe memory usage. This makes it easier to calculate a value for max server memory, which becomes important when configuring virtual machines to work well with Hyper-V Dynamic Memory Startup and Maximum RAM settings.   Another important change is no more AWE or hot-add support for 32-bit edition. This means if you're running a 32-bit edition of Denali you're limited to a 4GB address space and will not be able to take advantage of dynamically added OS memory that wasn't present when SQL Server started (though Hyper-V Dynamic Memory is still a supported configuration).   In part 3 we’ll develop some best practices for configuring and using SQL Server with Dynamic Memory. Originally posted at http://blogs.msdn.com/b/sqlosteam/

    Read the article

  • How to Reuse Your Old Wi-Fi Router as a Network Switch

    - by Jason Fitzpatrick
    Just because your old Wi-Fi router has been replaced by a newer model doesn’t mean it needs to gather dust in the closet. Read on as we show you how to take an old and underpowered Wi-Fi router and turn it into a respectable network switch (saving your $20 in the process). Image by mmgallan. Why Do I Want To Do This? Wi-Fi technology has changed significantly in the last ten years but Ethernet-based networking has changed very little. As such, a Wi-Fi router with 2006-era guts is lagging significantly behind current Wi-Fi router technology, but the Ethernet networking component of the device is just as useful as ever; aside from potentially being only 100Mbs instead of 1000Mbs capable (which for 99% of home applications is irrelevant) Ethernet is Ethernet. What does this matter to you, the consumer? It means that even though your old router doesn’t hack it for your Wi-Fi needs any longer the device is still a perfectly serviceable (and high quality) network switch. When do you need a network switch? Any time you want to share an Ethernet cable among multiple devices, you need a switch. For example, let’s say you have a single Ethernet wall jack behind your entertainment center. Unfortunately you have four devices that you want to link to your local network via hardline including your smart HDTV, DVR, Xbox, and a little Raspberry Pi running XBMC. Instead of spending $20-30 to purchase a brand new switch of comparable build quality to your old Wi-Fi router it makes financial sense (and is environmentally friendly) to invest five minutes of your time tweaking the settings on the old router to turn it from a Wi-Fi access point and routing tool into a network switch–perfect for dropping behind your entertainment center so that your DVR, Xbox, and media center computer can all share an Ethernet connection. What Do I Need? For this tutorial you’ll need a few things, all of which you likely have readily on hand or are free for download. To follow the basic portion of the tutorial, you’ll need the following: 1 Wi-Fi router with Ethernet ports 1 Computer with Ethernet jack 1 Ethernet cable For the advanced tutorial you’ll need all of those things, plus: 1 copy of DD-WRT firmware for your Wi-Fi router We’re conducting the experiment with a Linksys WRT54GL Wi-Fi router. The WRT54 series is one of the best selling Wi-Fi router series of all time and there’s a good chance a significant number of readers have one (or more) of them stuffed in an office closet. Even if you don’t have one of the WRT54 series routers, however, the principles we’re outlining here apply to all Wi-Fi routers; as long as your router administration panel allows the necessary changes you can follow right along with us. A quick note on the difference between the basic and advanced versions of this tutorial before we proceed. Your typical Wi-Fi router has 5 Ethernet ports on the back: 1 labeled “Internet”, “WAN”, or a variation thereof and intended to be connected to your DSL/Cable modem, and 4 labeled 1-4 intended to connect Ethernet devices like computers, printers, and game consoles directly to the Wi-Fi router. When you convert a Wi-Fi router to a switch, in most situations, you’ll lose two port as the “Internet” port cannot be used as a normal switch port and one of the switch ports becomes the input port for the Ethernet cable linking the switch to the main network. This means, referencing the diagram above, you’d lose the WAN port and LAN port 1, but retain LAN ports 2, 3, and 4 for use. If you only need to switch for 2-3 devices this may be satisfactory. However, for those of you that would prefer a more traditional switch setup where there is a dedicated WAN port and the rest of the ports are accessible, you’ll need to flash a third-party router firmware like the powerful DD-WRT onto your device. Doing so opens up the router to a greater degree of modification and allows you to assign the previously reserved WAN port to the switch, thus opening up LAN ports 1-4. Even if you don’t intend to use that extra port, DD-WRT offers you so many more options that it’s worth the extra few steps. Preparing Your Router for Life as a Switch Before we jump right in to shutting down the Wi-Fi functionality and repurposing your device as a network switch, there are a few important prep steps to attend to. First, you want to reset the router (if you just flashed a new firmware to your router, skip this step). Following the reset procedures for your particular router or go with what is known as the “Peacock Method” wherein you hold down the reset button for thirty seconds, unplug the router and wait (while still holding the reset button) for thirty seconds, and then plug it in while, again, continuing to hold down the rest button. Over the life of a router there are a variety of changes made, big and small, so it’s best to wipe them all back to the factory default before repurposing the router as a switch. Second, after resetting, we need to change the IP address of the device on the local network to an address which does not directly conflict with the new router. The typical default IP address for a home router is 192.168.1.1; if you ever need to get back into the administration panel of the router-turned-switch to check on things or make changes it will be a real hassle if the IP address of the device conflicts with the new home router. The simplest way to deal with this is to assign an address close to the actual router address but outside the range of addresses that your router will assign via the DHCP client; a good pick then is 192.168.1.2. Once the router is reset (or re-flashed) and has been assigned a new IP address, it’s time to configure it as a switch. Basic Router to Switch Configuration If you don’t want to (or need to) flash new firmware onto your device to open up that extra port, this is the section of the tutorial for you: we’ll cover how to take a stock router, our previously mentioned WRT54 series Linksys, and convert it to a switch. Hook the Wi-Fi router up to the network via one of the LAN ports (consider the WAN port as good as dead from this point forward, unless you start using the router in its traditional function again or later flash a more advanced firmware to the device, the port is officially retired at this point). Open the administration control panel via  web browser on a connected computer. Before we get started two things: first,  anything we don’t explicitly instruct you to change should be left in the default factory-reset setting as you find it, and two, change the settings in the order we list them as some settings can’t be changed after certain features are disabled. To start, let’s navigate to Setup ->Basic Setup. Here you need to change the following things: Local IP Address: [different than the primary router, e.g. 192.168.1.2] Subnet Mask: [same as the primary router, e.g. 255.255.255.0] DHCP Server: Disable Save with the “Save Settings” button and then navigate to Setup -> Advanced Routing: Operating Mode: Router This particular setting is very counterintuitive. The “Operating Mode” toggle tells the device whether or not it should enable the Network Address Translation (NAT)  feature. Because we’re turning a smart piece of networking hardware into a relatively dumb one, we don’t need this feature so we switch from Gateway mode (NAT on) to Router mode (NAT off). Our next stop is Wireless -> Basic Wireless Settings: Wireless SSID Broadcast: Disable Wireless Network Mode: Disabled After disabling the wireless we’re going to, again, do something counterintuitive. Navigate to Wireless -> Wireless Security and set the following parameters: Security Mode: WPA2 Personal WPA Algorithms: TKIP+AES WPA Shared Key: [select some random string of letters, numbers, and symbols like JF#d$di!Hdgio890] Now you may be asking yourself, why on Earth are we setting a rather secure Wi-Fi configuration on a Wi-Fi router we’re not going to use as a Wi-Fi node? On the off chance that something strange happens after, say, a power outage when your router-turned-switch cycles on and off a bunch of times and the Wi-Fi functionality is activated we don’t want to be running the Wi-Fi node wide open and granting unfettered access to your network. While the chances of this are next-to-nonexistent, it takes only a few seconds to apply the security measure so there’s little reason not to. Save your changes and navigate to Security ->Firewall. Uncheck everything but Filter Multicast Firewall Protect: Disable At this point you can save your changes again, review the changes you’ve made to ensure they all stuck, and then deploy your “new” switch wherever it is needed. Advanced Router to Switch Configuration For the advanced configuration, you’ll need a copy of DD-WRT installed on your router. Although doing so is an extra few steps, it gives you a lot more control over the process and liberates an extra port on the device. Hook the Wi-Fi router up to the network via one of the LAN ports (later you can switch the cable to the WAN port). Open the administration control panel via web browser on the connected computer. Navigate to the Setup -> Basic Setup tab to get started. In the Basic Setup tab, ensure the following settings are adjusted. The setting changes are not optional and are required to turn the Wi-Fi router into a switch. WAN Connection Type: Disabled Local IP Address: [different than the primary router, e.g. 192.168.1.2] Subnet Mask: [same as the primary router, e.g. 255.255.255.0] DHCP Server: Disable In addition to disabling the DHCP server, also uncheck all the DNSMasq boxes as the bottom of the DHCP sub-menu. If you want to activate the extra port (and why wouldn’t you), in the WAN port section: Assign WAN Port to Switch [X] At this point the router has become a switch and you have access to the WAN port so the LAN ports are all free. Since we’re already in the control panel, however, we might as well flip a few optional toggles that further lock down the switch and prevent something odd from happening. The optional settings are arranged via the menu you find them in. Remember to save your settings with the save button before moving onto a new tab. While still in the Setup -> Basic Setup menu, change the following: Gateway/Local DNS : [IP address of primary router, e.g. 192.168.1.1] NTP Client : Disable The next step is to turn off the radio completely (which not only kills the Wi-Fi but actually powers the physical radio chip off). Navigate to Wireless -> Advanced Settings -> Radio Time Restrictions: Radio Scheduling: Enable Select “Always Off” There’s no need to create a potential security problem by leaving the Wi-Fi radio on, the above toggle turns it completely off. Under Services -> Services: DNSMasq : Disable ttraff Daemon : Disable Under the Security -> Firewall tab, uncheck every box except “Filter Multicast”, as seen in the screenshot above, and then disable SPI Firewall. Once you’re done here save and move on to the Administration tab. Under Administration -> Management:  Info Site Password Protection : Enable Info Site MAC Masking : Disable CRON : Disable 802.1x : Disable Routing : Disable After this final round of tweaks, save and then apply your settings. Your router has now been, strategically, dumbed down enough to plod along as a very dependable little switch. Time to stuff it behind your desk or entertainment center and streamline your cabling.     

    Read the article

< Previous Page | 19 20 21 22 23 24 25  | Next Page >