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  • Updating access 2000 database through code in VB6

    - by Mark
    I have an application that uses an access 2000 database currently in distribution. I need to update one of the recordsets with additional fields on my customer's computers. My data controls work fine as I have them set to connect in access 2000 format but when I try to open the database in code, I get an unrecognized data format error. What is the best way to replace or add to the database on their machines? Any help is greatly appreciated.

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  • How to run dubug file on another computer

    - by Pazzy
    I have a debug .exe file that i want to run on other machines that don't have MS Visual Studio 2008 installed on them. How can this be done? The release option doesn't work as the application does not function correctly when build in release (not sure why). At the moment I'm getting a message saying "This application has failed to start because the application configuration is incorrect". An ideas? Cheers.

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  • How do I uninstall the .NET framework?

    - by spelunk
    I'm having a problem running a VS 2005 app on some machines and not others. I looked up the error message on google and found a post by someone who had the same error and fixed it by uninstalling and reinstalling the .NET framework. When I try to do that, Windows won't let me because it is in use. Am I expected to uninstall everything that is using the framework first, then uninstall the framework, then reinstall, etc.? Does anyone know of an easier way?

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  • Scenarios for Bazaar and SVN interaction

    - by Adam Badura
    At our company we are using SVN repository. I'm doing programming from both work (main place) and home (mostly experiments and refactoring). Those are two different machines, in different networks and almost never turned on at the same time (after all I'm either at work or at home...) I wanted to give a chance to some distributed version control system and solve some of the issues associated with SVN based process and having two machines. From git, Mercurial and Bazaar I chose to start with Bazaar since it claims that it is designed do be used by human beings. Its my first time with distributed system and having nice and easy user interface was important for me. Features I wanted to achieve were: Being able to update from SVN repository and commit to it. Being able to commit locally steps of my work on a task. Being able to have few separate tasks at the same time in their own local branches. Being able to share those branches between my work and home computer. As a means of transport between work and home computer I wanted to use a pen-drive. Company server will not work since I may not instal there anything. Neither will work a web service repository as I may not upload source code to web (especially if it would be public which seems to be a common case in free web services). This transport should be Bazaar-based (or what ever else I will end with) so it can be done more or less automatically but manual copying and pasting some folders or generating patch files (providing they would work - I have bad experience with patch files in SVN) would work as well if there is no better solution. Yet the pen-drive should only be used for transportation. I do not want to edit or build there. I tried following Bazaar guidelines for integration with SVN. But I failed. I tried both bzr svn-import and bzr checkout providing URL from my repository as both https://... and svn+https://.... In some cases it had some issues with certificates but the output specified argument to ignore them so I did that. Sometimes it asked me to log in (in other cases maybe it remembered... I don't know) which I did. All were running very slow (this could be our server issue) and at some point were interrupted due to connection interruption (this almost for sure is our server issue: it truncates the connection after some time). But since (as opposed to SVN) restarting starts a new rather than from point where it was interrupted I was unable to reach all the ~19000 revisions (ending usually somewhere around 150). What and how should I do with Bazaar? Is is possible to somehow import SVN repository from the local checkout (so that I do not suffer the connection truncation)? I was told that a colleague that used to work with us has done something similar (importing SVN repository with full history) with Mercurial like in no time. So I'm seriously considering now trying Mercurial even if only to see if that will work. But also what are your general guidelines to achieve the listed features?

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  • Recommendations for distributed processing/distributed storage systems

    - by Eddie
    At my organization we have a processing and storage system spread across two dozen linux machines that handles over a petabyte of data. The system right now is very ad-hoc; processing automation and data management is handled by a collection of large perl programs on independent machines. I am looking at distributed processing and storage systems to make it easier to maintain, evenly distribute load and data with replication, and grow in disk space and compute power. The system needs to be able to handle millions of files, varying in size between 50 megabytes to 50 gigabytes. Once created, the files will not be appended to, only replaced completely if need be. The files need to be accessible via HTTP for customer download. Right now, processing is automated by perl scripts (that I have complete control over) which call a series of other programs (that I don't have control over because they are closed source) that essentially transforms one data set into another. No data mining happening here. Here is a quick list of things I am looking for: Reliability: These data must be accessible over HTTP about 99% of the time so I need something that does data replication across the cluster. Scalability: I want to be able to add more processing power and storage easily and rebalance the data on across the cluster. Distributed processing: Easy and automatic job scheduling and load balancing that fits with processing workflow I briefly described above. Data location awareness: Not strictly required but desirable. Since data and processing will be on the same set of nodes I would like the job scheduler to schedule jobs on or close to the node that the data is actually on to cut down on network traffic. Here is what I've looked at so far: Storage Management: GlusterFS: Looks really nice and easy to use but doesn't seem to have a way to figure out what node(s) a file actually resides on to supply as a hint to the job scheduler. GPFS: Seems like the gold standard of clustered filesystems. Meets most of my requirements except, like glusterfs, data location awareness. Ceph: Seems way to immature right now. Distributed processing: Sun Grid Engine: I have a lot of experience with this and it's relatively easy to use (once it is configured properly that is). But Oracle got its icy grip around it and it no longer seems very desirable. Both: Hadoop/HDFS: At first glance it looked like hadoop was perfect for my situation. Distributed storage and job scheduling and it was the only thing I found that would give me the data location awareness that I wanted. But I don't like the namename being a single point of failure. Also, I'm not really sure if the MapReduce paradigm fits the type of processing workflow that I have. It seems like you need to write all your software specifically for MapReduce instead of just using Hadoop as a generic job scheduler. OpenStack: I've done some reading on this but I'm having trouble deciding if it fits well with my problem or not. Does anyone have opinions or recommendations for technologies that would fit my problem well? Any suggestions or advise would be greatly appreciated. Thanks!

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  • Strange Upload Problem on Hyper-V

    - by Ring0
    Hi, This one is driving me totally nuts. I have being trying to upload a file to www.virustotal.com (its a harmless exe I have since found out - DiskWipe.exe from diskwipe.org). Using IE8. From Win 7 and Win 2008 R2 Datacenter (which I select to boot from vhd's) onto my main machine hardware, and also on another Win 7 PC elsewhere on my network, when I upload the file to virustotal.com it works perfectly. So, using my native NIC's everything is fine. Using another machine also perfect. Right. OK, from my boot menu the default is my main development machine - the one I'm typing on now. This runs on the metal and has Hyper-V role and I have some guests. All guests are not running. Amazingly, from my console (root partition to be exact) or any guest OS 2003 /XP / 2008 R2 etc. My upload to virustotal.com slows at 32% then HANGS at 38.something% & never finishes!! Here is the kicker. I have another box (my main server) running Hyper-V on the metal and three live guests. Identical H/W to my main dev machine in another room. (Except OS is Datacenter - Mine is Enterprise). If I try and upload from its bare metal console or any guest this file to virustotal.com using IE8 it stops exactly in the same place!! As for "steps I have tried etc." are kind-of blown out of the water as my server box is doing the precise same thing as the machine in my room here. OK, comonalities: Mobo: Gigabyte GA-X58-UD5, 12GB Kingston RAM, Corei7 920 4 cores hyperthreading = 8 & Realtek RTL8168D/8111D Family PCI-E Gigabit Ethernet NIC's. All 3 machines have this same motherboard - revision F11 Bios, all have 12GB RAM, all have the Realtek Nic's. All x64 by the way as I mentioned before I have a Win 7 box also with the UD5 m/Board, 12 GB RAM - bit of an overkill. :-) All these machines when NOT running Hyper-V can upload this file. Perhaps you may like to try it on a Hyepr-v (2008 R2) yourselves with IE8 and the desktop experience is on. See if it works or fails for you. Root OS or any guest. So, looking like its the NIC + Hyper-V = Cannot upload this file (any file I must add.) Realtek Nic is Ver 7.002.1125.2008. Using IE8 I see in the nic settings there are the usual parameters for Jumbo frames / Checksum offloading etc. several others. Should I fiddle with these? I ran Netmon 3.3 in a guest and the TCP session halted as the upload failed. I suppose I could study that further. I dont have Netmon on the root partition machine (yet)! All OS's fully patched - including todays defender files. My box running Office 2007 - but identical server in another room is not. Also, if I fire up a VPN to a distant client and do the upload it works! Of course its a different network path. Suggestions welcome please. If I left out anything important - please yell at me. Many Thanks,

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  • How to set up a centralized backup server with lots of offsite workstations, intermittent internet connectivity, and stubborn users?

    - by Zac B
    This might be an impossible question. Context: We have a bunch of computers across around 1000 users. We have a centralized office where 900 of the users work, most of the time. Most of the computers are laptops. They are very frequently coming on and off the network for hours at a time. Users often take their computers home and do lots of work from home. In addition, there are a handful of users who work elsewhere in the country, who are offline (no internet connection whatsoever) for more than half of the time they use their machines. All of the machines are Windows 7/XP. Problem: People are always losing data. One day someone accidentally deletes a bunch of files. The next day someone else installs a bad driver or tries to mess with something in system32 and needs a personal data backup/reinstall of Windows. Because of how many of our business operations are done without an internet connection, and how frequently computers come on- and offline, it's unfeasible to make users use network storage for all of their data. We tried giving them Dropboxes, and they stored their files elsewhere. We bought and deployed Altiris, and they uninstalled it and blamed us when they couldn't get files back that they accidentally deleted while they were offline and hadn't taken a backup in months. We tried teaching them backup best-practices, and using scheduled sync tools to upload things to the network drives, and they turned them off because they "looked like viruses". It doesn't help that many of these users are pretty high up in the business and are not amicable to any sort of "you need to do something regularly because we say so" solution. Question: Other than finding another job where IT is treated differently and users are willing to follow best practices, how would people recommend I implement a file backup solution that supports the following: Backs up to a centralized server over LAN or WAN whenever a network link becomes available, or on a schedule. Supports interrupted/resumed backups (and hopefully file-delta only backups), since connections to the network (WAN or LAN) are often slow and only open for half an hour or so. Supports relatively rapid, "I accidentally deleted the TPS reports! Oh no!" single-file recovery, ideally administered from the central backup server rather than the client PC. Supports local-to-local file delta backup on a schedule, so that users without a network connection for a few days can still retrieve accidental deletions or whatnot. Ideally, the local stored backups would be pushed up to the server whenever network link is available. Isn't configurable on the clients without certain credentials. Because the CFOs (who won't give up their admin rights on the domain) will disable it if they can. Backs up the entire hard drive. There are people who are self-righteous about storing things in C:\, or in the recycle bin, or in the C:\Windows dir (yes, I know). I'm fine integrating multiple products/solutions, or scripting different programs together myself (I'm a somewhat competent programmer), but I've been drawing a blank on where to start. Dropbox is folder-specific, Altiris doesn't cope with LAN outages or interrupted/resumed backups, Volume Shadow Copy is awesome for a local-to-local solution, but I don't know how to push days of stored shadow copies up to a server in a 2 hour window of network access. The company is fine with spending decent money on this, thousands (USD) on a server, and hundreds on clients, if necessary. I want to emphasize that this isn't a shopping list request. While I wish there was a program out there that did what I want, I've looked pretty hard, and not found anything that fits the bill. Instead, I'm hoping for ideas on where to start hacking things together from scratch/from different technologies to make something stable that works. Cheers!

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  • Neighbour table overflow on Linux hosts related to bridging and ipv6

    - by tim
    Note: I already have a workaround for this problem (as described below) so this is only a "want-to-know" question. I have a productive setup with around 50 hosts including blades running xen 4 and equallogics providing iscsi. All xen dom0s are almost plain Debian 5. The setup includes several bridges on every dom0 to support xen bridged networking. In total there are between 5 and 12 bridges on each dom0 servicing one vlan each. None of the hosts has routing enabled. At one point in time we moved one of the machines to a new hardware including a raid controller and so we installed an upstream 3.0.22/x86_64 kernel with xen patches. All other machines run debian xen-dom0-kernel. Since then we noticed on all hosts in the setup the following errors every ~2 minutes: [55888.881994] __ratelimit: 908 callbacks suppressed [55888.882221] Neighbour table overflow. [55888.882476] Neighbour table overflow. [55888.882732] Neighbour table overflow. [55888.883050] Neighbour table overflow. [55888.883307] Neighbour table overflow. [55888.883562] Neighbour table overflow. [55888.883859] Neighbour table overflow. [55888.884118] Neighbour table overflow. [55888.884373] Neighbour table overflow. [55888.884666] Neighbour table overflow. The arp table (arp -n) never showed more than around 20 entries on every machine. We tried the obvious tweaks and raised the /proc/sys/net/ipv4/neigh/default/gc_thresh* values. FInally to 16384 entries but no effect. Not even the interval of ~2 minutes changed which lead me to the conclusion that this is totally unrelated. tcpdump showed no uncommon ipv4 traffic on any interface. The only interesting finding from tcpdump were ipv6 packets bursting in like: 14:33:13.137668 IP6 fe80::216:3eff:fe1d:9d01 > ff02::1:ff1d:9d01: HBH ICMP6, multicast listener reportmax resp delay: 0 addr: ff02::1:ff1d:9d01, length 24 14:33:13.138061 IP6 fe80::216:3eff:fe1d:a8c1 > ff02::1:ff1d:a8c1: HBH ICMP6, multicast listener reportmax resp delay: 0 addr: ff02::1:ff1d:a8c1, length 24 14:33:13.138619 IP6 fe80::216:3eff:fe1d:bf81 > ff02::1:ff1d:bf81: HBH ICMP6, multicast listener reportmax resp delay: 0 addr: ff02::1:ff1d:bf81, length 24 14:33:13.138974 IP6 fe80::216:3eff:fe1d:eb41 > ff02::1:ff1d:eb41: HBH ICMP6, multicast listener reportmax resp delay: 0 addr: ff02::1:ff1d:eb41, length 24 which placed the idea in my mind that the problem maybe related to ipv6, since we have no ipv6 services in this setup. The only other hint was the coincidence of the host upgrade with the beginning of the problems. I powered down the host in question and the errors were gone. Then I subsequently took down the bridges on the host and when i took down (ifconfig down) one particularly bridge: br-vlan2159 Link encap:Ethernet HWaddr 00:26:b9:fb:16:2c inet6 addr: fe80::226:b9ff:fefb:162c/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:120 errors:0 dropped:0 overruns:0 frame:0 TX packets:9 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:5286 (5.1 KiB) TX bytes:726 (726.0 B) eth0.2159 Link encap:Ethernet HWaddr 00:26:b9:fb:16:2c inet6 addr: fe80::226:b9ff:fefb:162c/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1801 errors:0 dropped:0 overruns:0 frame:0 TX packets:20 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:126228 (123.2 KiB) TX bytes:1464 (1.4 KiB) bridge name bridge id STP enabled interfaces ... br-vlan2158 8000.0026b9fb162c no eth0.2158 br-vlan2159 8000.0026b9fb162c no eth0.2159 The errors went away again. As you can see the bridge holds no ipv4 address and it's only member is eth0.2159 so no traffic should cross it. Bridge and interface .2159 / .2157 / .2158 which are in all aspects identical apart from the vlan they are connected to had no effect when taken down. Now I disabled ipv6 on the entire host via sysctl net.ipv6.conf.all.disable_ipv6 and rebooted. After this even with bridge br-vlan2159 enabled no errors occur. Any ideas are welcome.

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  • Hour-long shutdown duration "shutting down hyper-v virtual machine management service"

    - by icelava
    I have a Windows 2008 R2 server that is a Hyper-V host (Dell PowerEdge T300). Today for the first time I encountered an odd situation; i lost connection with one of the guest machines but logging on physically it seems the guest OS is still running but no longer contactable via the network. I tried to shut down the guest machine (Windows XP) but it would not shut down, getting stuck in a "Not responding" dialog box that cannot be dismissed. I used the Hyper-V management console to reset the machine and it could not get out of resetting state. I tried to save another Windows 2003 guest machine, and it would be progress with its Saving state (0%). The other running Windows 2003 guest was stuck in the logon dialog. My first suspicion is perhaps one of the Windows update patches this week (10 Nov 2011) may something to do with it, which was still pending a system restart. Well, since I could not do anything with Hyper-V i proceeded with the Windows Update restart, and now it is stuck half an hour at "Shutting down hyper-v virtual machine management service" Prior to restarting I did not observe any hard disk errors reported in the system event log; doubt it is a disk-related condition. Shall I force a hard reboot? UPDATE Ok so i left it hanging over an hour while attending to other matters, and thankfully the host cleanly restarted. I can operate the guest machines fine now. Phew. Hyper-V must have been crawling for some reason. The VMs have been observed to become slow in the past when the host has been up for a long duration (two weeks to a month), but never this slow. Would love to know what types of performance monitoring items i can observe to give a hint why this can happen. UPDATE 2012-02-13 In the months ever since, Hyper-V has stalled into this state another two times. It appears so randomly and without any error event logs to hint what is causing it enter this "drunkard" state. Just an Hyper-V management service timeout. Log Name: System Source: Service Control Manager Date: 13/2/2012 9:16:48 AM Event ID: 7043 Task Category: None Level: Error Keywords: Classic User: N/A Computer: elune Description: The Hyper-V Virtual Machine Management service did not shut down properly after receiving a preshutdown control. Event Xml: <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> <System> <Provider Name="Service Control Manager" Guid="{555908d1-a6d7-4695-8e1e-26931d2012f4}" EventSourceName="Service Control Manager" /> <EventID Qualifiers="49152">7043</EventID> <Version>0</Version> <Level>2</Level> <Task>0</Task> <Opcode>0</Opcode> <Keywords>0x8080000000000000</Keywords> <TimeCreated SystemTime="2012-02-13T01:16:48.882901900Z" /> <EventRecordID>567844</EventRecordID> <Correlation /> <Execution ProcessID="764" ThreadID="8484" /> <Channel>System</Channel> <Computer>elune</Computer> <Security /> </System> <EventData> <Data Name="param1">Hyper-V Virtual Machine Management</Data> </EventData> </Event> The only means out of it is to restart the system.

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  • Can spliting an access database cause printer and reporting issues?

    - by leeand00
    We have a setup in which our users log into an access database using MS Access 2003 over an RDP connection. The user's login to their own machines first using a roaming profile. They then click an rdp connection file on the desktop and login to the remote server, via RDP, where they use MS Access as the shell; they don't have any access to any of explorer.exe features such as the start menu. The database they are logging into is more of an application, and provides functionality for entering data, querying data, and running reports via form based menus. It all worked pretty well until we split the database as it was nearing 2GBs in size. We moved out the payroll data into a separate partition, a database with the same name in a different folder, both of them on the server. Only two tables were moved into this new database partition, and they were re-linked as external tables in the new partition. Now while everything appears to be working fine data-wise after the split, there's a new issue when our users login via RDP and attempt to run reports: often the report will not display and instead the user sees an error about the click event of the form. At first I didn't even know it was printer-related, as we didn't really change anything related to the printers as far as I knew. Confused about the error, I talked to the guy who previously worked here and who was in charge of splitting the database, and he told me to tell the users to set their default printers (on their local machines, not on the server) to the "printer" Microsoft XPS Document Writer which isn't a physical printer at all. This allowed the user's to display their reports, but if they want to print out reports, they are required to go to the File menu and select Print, clicking the print icon on the toolbar takes them to a Save As... dialog as would be expected when using the Microsoft XPS Document Writer as your default printer. It's easy to tell if the user is having a problem because a quick mouseover of the printer icon will yield a tooltip of (none) when they cannot access their reports, and a tooltip of Microsoft XPS Document Writer when they can view the reports. If the user's printer is set to anything other than Microsoft XPS Document Writer as the default on their local machine, then (none) is always displayed when they rdp to the database. The RDP settings are setup to transfer the local printer to the server. Telling the users to do this to print has been more of a band-aid on the whole situation until we find a better solution and an explanation as to why splitting a database would prevent users from printing or even viewing access database reports. Which is why I'm here asking this question. Also of note all the printers on the network now show up on the server so that when the users do click File->Print to print their reports on a physical printer, they have to look through a huge list of printers to find theirs in the dropdown. So the little band-aid fix we have is not ideal. Previously, only the printers on the user's local machine displayed here, and not all the printers on the network. My co-worker seems to think this has something to do with permissions, I personally think it has to do with roaming profiles, and Group Policies which is what I've been reading up on. I really don't know how to fix this or how it is related to splitting the database.

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  • Log transport and aggregation at scale

    - by markdrayton
    How're you analysing log files from UNIX/Linux machines? We run several hundred servers which all generate their own log files, either directly or through syslog. I'm looking for a decent solution to aggregate these and pick out important events. This problem breaks down into 3 components: 1) Message transport The classic way is to use syslog to log messages to a remote host. This works fine for applications that log into syslog but less useful for apps that write to a local file. Solutions for this might include having the application log into a FIFO connected to a program to send the message using syslog, or by writing something that will grep the local files and send the output to the central syslog host. However, if we go to the trouble of writing tools to get messages into syslog would we be better replacing the whole lot with something like Facebook's Scribe which offers more flexibility and reliability than syslog? 2) Message aggregation Log entries seem to fall into one of two types: per-host and per-service. Per-host messages are those which occur on one machine; think disk failures or suspicious logins. Per-service messages occur on most or all of the hosts running a service. For instance, we want to know when Apache finds an SSI error but we don't want the same error from 100 machines. In all cases we only want to see one of each type of message: we don't want 10 messages saying the same disk has failed, and we don't want a message each time a broken SSI is hit. One approach to solving this is to aggregate multiple messages of the same type into one on each host, send the messages to a central server and then aggregate messages of the same kind into one overall event. SER can do this but it's awkward to use. Even after a couple of days of fiddling I had only rudimentary aggregations working and had to constantly look up the logic SER uses to correlate events. It's powerful but tricky stuff: I need something which my colleagues can pick up and use in the shortest possible time. SER rules don't meet that requirement. 3) Generating alerts How do we tell our admins when something interesting happens? Mail the group inbox? Inject into Nagios? So, how're you solving this problem? I don't expect an answer on a plate; I can work out the details myself but some high-level discussion on what is surely a common problem would be great. At the moment we're using a mishmash of cron jobs, syslog and who knows what else to find events. This isn't extensible, maintainable or flexible and as such we miss a lot of stuff we shouldn't. Updated: we're already using Nagios for monitoring which is great for detected down hosts/testing services/etc but less useful for scraping log files. I know there are log plugins for Nagios but I'm interested in something more scalable and hierarchical than per-host alerts.

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  • How to use iptables to forward all data from an IP to a Virtual Machine

    - by jro
    OK, in an attempt to get some response, a TL;DR version. I know that the following command: iptables -A PREROUTING -t nat -i eth0 --dport 80 --source 1.1.1.1 -j REDIRECT --to-port 8080 ... will redirect all traffic from port 80 to port 8080. The problem is that I have to do this for every port that is to be redirected. To be future-proof, I want all ports for an IP to be redirected to a different (internal) IP, so that if one might decide to enable SSH, they can directly connect without worrying about iptables. What is needed to reliable forward all traffic from an external IP, to an internal IP, and vice versa? Extended version I've scoured the internet for this, but I never got a solid answer. What I have is one physical server (HOST), with several virtual machines (VM) that need traffic redirected to them. Just getting it to work with a single machine is enough for now. The VM's run under VirtualBox, and are set to use a host-only adapter (vboxnet0). Everything seems to work, but it is greatly lagging. Both the host (CentOS 5.6) and the guest (Ubuntu 10.04) machine are running Linux. What I did was the following: Configure the VM to have a static IP in the network of the vboxnet0 adapter. Add an IP alias to the host, registering to the dedicated (outside) IP. Setup iptables to allow traffic to come through (via sysctl). Configure iptables to DNAT and SNAT data from a given IP address to the internal address. iptables commands: sudo iptables -A FORWARD -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT sudo iptables -A POSTROUTING -t nat -j MASQUERADE iptables -t nat -I PREROUTING -d $OUT_IP -I eth0 -j DNAT --to-destination $IN_IP iptables -t nat -I POSTROUTING -s $IN_IP -o eth0 -j SNAT --to-source $OUT_IP Now the site works, but is really, really slow. I'm hoping I missed something simple, but I'm out of ideas for now. Some background info: before this, the site was working with basic port forwarding. E.g. port 80 was mapped to port 8080 using iptables. In VirtualBox (having the network adapter configured as NAT), a port forwarding the other way around made things work beautifully. The problem was twofold: first, multiple ports needed to be forwarded (for admin interfaces, https, ssh, etc). Second, it only allowed one IP address to use port 80. To resolve things, multiple external IP addresses are used for different (sub)domains. Likewise, the "VirtualBox" network will contain the virtual machines: DNS Ext. IP Adapter VM "VirtalBox" IP ------------------------------------------------------------------ a.example.com 1.1.1.1 eth0:1 vm_guest_1 192.168.56.1 b.example.com 2.2.2.2 eth0:2 vm_guest_2 192.168.56.2 c.example.com 3.3.3.3 eth0:3 vm_guest_3 192.168.56.3 And so on. Put simply, the goal is to channel all traffic from a.example.com to vm_guest_1 (of put differently, from 1.1.1.1 to 192.168.56.1). And achieve this with an acceptable speed :).

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  • How does the Cloud compare to Colocation? And development too

    - by David
    Currently I/we run a SaaS web application where each subscriber has their own physical instance of the application in addition to their own database. The setup has each web application instance deployed on two different IIS boxes both for load-balancing and redundancy (the machines have their Windows Update install times 12 hours apart, for example). Databases are mirrored on two different SQL Server 2012 machines with AlwaysOn for uptime. I don't make use of SQL Server clustering (as it doesn't provide storage-level failover: we don't have a shared storage box). Because it's a Windows setup it means there are two Domain Controllers (we cheat: they're both Mac Minis, 17W each, which keeps our colo power costs low). Finally there's also an Exchange server (Mailbox, Hub Transport and Client Access). One of the SQL Servers also doubles-up as an Exchange Hub Transport. Running costs are about $700 a month for our quarter-rack colocation (which includes power and peering/transfer), then there's about $150 a month for SPLA licensing, so $850 a month in total. Then there's the hard-to-quantify cost of administration, but I reckon I spend a couple of hours a week checking-in on the servers: reviewing event logs, etc. I keep getting bombarded by ads and manufactured news stories about how great "the cloud" is. Back in 2008 when the cloud was taking off I was reading up about the proper "cloud" services like Google AppEngine, where you write in Python against Google's API and that's how they scale your application across servers and also use their database provider for scaling storage. Simple enough to understand. Then came along Amazon, and I understand how Amazon Storage works, but I'm not sure how Amazon Compute works: web application pages don't take much CPU time to compute, how do you even quantify usage anyway? Finally, RackSpace gets in the act and now I'm really confused. RackSpace advertise "Cloud" SQL Server 2012 available for about "$0.70 per hour", going by how they advertise it I thought the "hour" meant the sum of CPU time, IO blocking time, maybe time spent transferring data, so for a low-intensity application that works out pretty cheap then? Nope. I went on to a Sales Chat window and spoke to one of their advisors. They told me the $0.70/hour was actually for every hour the SQL Server is running... but who wants a SQL Server for only a few hours? You're going to need it available 24 hours a day for months on end. $0.70 * 24 * 31 works out at $520 a month, which is rediculously expensive for SQL Server. An SPLA license for SQL Server is only $50 a month or so. That $520 a month does not include "fanatical support", and you also need to stack on top the costs of the host Windows server instance too. From what I can tell, Rackspace's "Cloud" products seem like like an cynical rebranding of an overpriced VPS service, but priced by the hour. I have the same confusion about Windows Azure which uses similar terms to describe the products available, but I think that's because Azure offers both traditional shared webhosting in addition to their own APIs you can target for scalable applications.

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  • Windows Update and IE fail to connect, but Chrome fine?

    - by I Gottlieb
    Out of ideas on this one. (Running Windows Vista.) I have a program that accesses the internet to retrieve financial market data. One day it tells me that it can't log in -- timeout error. I check the documentation and it says must have a working copy of IE browser installed. I check IE (have IE9) and sure enough -- it just spins. No error message, not timeout, no 'try later' -- just spins -- as far as I can tell, indefinitely. Any page, any address. Even access to a localhost site just spins. Chrome works fine. So does another program I have that fetches market data. Windows 'diagnose and repair' says my internet connection is working fine. I tried uninstall/re-install of IE. Same spinning. I tried to install Windows Updates, and guess what? I can't. I comes up with error 80072efd; checked documentation for the error and it says I should check firewall blockage. Thing is, the only firewall I have is Windows Firewall, and obviously it wouldn't be blocking Windows Update. In contrast, Windows 'Help' in all programs has no problem accessing the Internet. I had a filter on the internet connection, and this was updated just prior to first appearance of the problem. But I uninstalled the filter entirely (official, with passwd from the company's service rep) -- and no difference. I'm guessing that a high level Windows network service file is corrupted -- used only by MS programs and their ilk, but how do I find it? I'd like to avoid having to do a clean install of Windows. Much obliged for any insight. IG Ramhound -- Thanks for reply. I'm familiar with virtual machines as in e.g. JVM or an emulator for an alternative architecture or (theoretical) Turing Machine equivalence. But I'm not familiar with the way you're using the term. Please clarify -- what one needs for this VM 'test' and why you expect it will provide an advantage of insight into the problem. And what sort of 'configuration issue' are you referring to? IG

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  • Week in Geek: USDA Chooses Microsoft for Cloud Services Edition

    - by Asian Angel
    This week we learned how to create geeky LED holiday lights with old bottles, dig deeper in Windows Defrag via the command prompt, use Google Chrome’s drag/drop feature to upload files easier, find great gift recommendations by looking through the How-To Geek holiday gift guide, and have fun adding Merry Christmas fonts to our computers. Photo by ntr23. Random Geek Links It has been a busy week, so we have extra news link goodness with information that is good for you to know. USDA making the move to Microsoft The U.S. Department of Agriculture has announced that it has chosen Microsoft to host things like e-mail, instant messaging, and collaboration through the software giant’s Business Productivity Online Suite. Google says it was cut off from USDA project bid Google is claiming that it was not given a chance to bid on a cloud-computing project for the U.S. Department of Agriculture, for which the contract was awarded to rival Microsoft. Apache is being forced into a Java Fork When Oracle rolled over Apache and Google’s objections to its Java plans in December, the scene was set for Apache to leave and, eventually, force a Java code fork. Tumblr explains daylong outage After experiencing an outage that started on Sunday afternoon and stretched through most of the day yesterday, Tumblr has explained what happened. Google demos Chrome OS, launches pilot program During a press briefing this week in San Francisco, Google launched the Chrome application store and demonstrated Chrome OS, its browser-centric netbook operating system. Don’t expect Spotify in U.S. this holiday season As of last week, Spotify had yet to sign a single licensing deal with a major label, after spending more than a year negotiating, multiple music sources told CNET. December 2010 Patch Tuesday will come with most bulletins ever According to the Microsoft Security Response Center, Microsoft will issue 17 Security Bulletins addressing 40 vulnerabilities on Tuesday, December 14. It will also host a webcast to address customer questions the following day. Hacker plants back door in Symbian firmware Indian hacker Atul Alex has had a look at the firmware for Symbian S60 smartphones and come up with a back door for it. PC quarantines raise tough complexities The concept of quarantining PCs to prevent widespread infection is “interesting, but difficult to implement, with far too many problems”, said security experts. Symantec: DDoS attacks hard to defend It has surfaced that the distributed denial of service (DDoS) attacks on Visa and MasterCard Web sites on Wednesday were carried out by a toolkit known as low orbit ion cannon (LOIC). Web Sockets and the risks of unfinished standards Enthusiasm for a promising new standard called Web Sockets has quickly cooled in some quarters as a potential security problem led some browser makers to hastily postpone support. Internet Explorer 9 to get tracking protection Microsoft is making changes to Internet Explorer 9’s security features that will better enable users to keep sites from tracking their activity across browsing sessions. NASA sold PCs with sensitive data NASA failed to remove sensitive data from computers that it sold, according to an audit report released this week. Cybercrooks create fake Amazon receipts The bad guys have created yet another online scam, this one involving fake Amazon receipts. World of Warcraft character move fees waived Until December 22, Blizzard will allow free realm transfers from 25 highly populated servers to alleviate log-in queues or performance issues. (The free transfers are one-way and one-time only.) SpaceX Dragon reaches orbit atop a Falcon with a fiery tail The Space Exploration Technologies corporation has become the first nongovernmental entity to put a vehicle into low Earth orbit. Geek Video of the Week If birds have wings, then why are the Angry Birds using slingshots? Photo by Dorkly Bits. Wait… Birds have Wings, Why are the Angry Ones Using Slingshots? Sysadmin Geek Tips How To Setup Email Alerts on Linux Using Gmail or SMTP Linux machines may require administrative intervention in countless ways, but without manually logging into them how would you know about it? Here’s how to setup emails to get notified when your machines want some tender love and attention. Random TinyHacker Links Red Panda Webcam Support Firefox and the Knoxville Zoo’s Red Panda program. Christmas Icons (Icons we like) Superb set of holiday icons by lgp85 at deviantArt. Download the .zip and use as .png or convert to .ico at Convertico.com or with tiny app Imagicon. Super User Questions Enjoy reading the great answers to this week’s popular questions from Super User Useful USB boot disks? DVD/CD burning .zip: is it more reliable, faster, longer lasting to burn a zip of files rather than the files as a folder? What are other ways to backup my files if I do not have an external drive? Anti virus what is the difference between these all? How can I block all Facebook elements/content? How-To Geek Weekly Article Recap Have you had a busy week between work and preparing for the holidays? Get caught up on your HTG reading with our hottest articles of the week. 20 Windows Keyboard Shortcuts You Might Not Know The 50 Best Registry Hacks that Make Windows Better LCD? LED? Plasma? The How-To Geek Guide to HDTV Technology HTG Explains: Which Linux File System Should You Choose? How to Use and Customize Google Chrome Web Apps One Year Ago on How-To Geek This week’s batch of retro geeky goodness is all about customizing Windows 7. ClassicShell Adds Classic Start Menu and Explorer Features to Windows 7 Get an Aero-Styled Classic Start Menu in Windows 7 Customize the Windows 7 Logon Screen Get the Classic Style Network Activity Indicator Back in Windows 7 How To Enable Check Boxes for Items In Windows 7 The Geek Note We would like you to join us in welcoming Jason Fitzpatrick to the writing staff here at How-To Geek. He started with us this past week, so take some time to read through his articles about the Wii, Kindle, & PlayStation 2 Peripherals and leave a friendly comment to say “Hi”! Got a great tip to share? Make sure to send it in to us at [email protected]. Photo by real00. Latest Features How-To Geek ETC The 50 Best Registry Hacks that Make Windows Better The How-To Geek Holiday Gift Guide (Geeky Stuff We Like) LCD? LED? Plasma? The How-To Geek Guide to HDTV Technology The How-To Geek Guide to Learning Photoshop, Part 8: Filters Improve Digital Photography by Calibrating Your Monitor Our Favorite Tech: What We’re Thankful For at How-To Geek Settle into Orbit with the Voyage Theme for Chrome and Iron Awesome Safari Compass Icons Set Escape from the Exploding Planet Wallpaper Move Your Tumblr Blog to WordPress Pytask is an Easy to Use To-Do List Manager for Your Ubuntu System Snowy Christmas House Personas Theme for Firefox

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  • Ajax Control Toolkit and Superexpert

    - by Stephen Walther
    Microsoft has asked my company, Superexpert Consulting, to take ownership of the development and maintenance of the Ajax Control Toolkit moving forward. In this blog entry, I discuss our strategy for improving the Ajax Control Toolkit. Why the Ajax Control Toolkit? The Ajax Control Toolkit is one of the most popular projects on CodePlex. In fact, some have argued that it is among the most successful open-source projects of all time. It consistently receives over 3,500 downloads a day (not weekends -- workdays). A mind-boggling number of developers use the Ajax Control Toolkit in their ASP.NET Web Forms applications. Why does the Ajax Control Toolkit continue to be such a popular project? The Ajax Control Toolkit fills a strong need in the ASP.NET Web Forms world. The Toolkit enables Web Forms developers to build richly interactive JavaScript applications without writing any JavaScript. For example, by taking advantage of the Ajax Control Toolkit, a Web Forms developer can add modal dialogs, popup calendars, and client tabs to a web application simply by dragging web controls onto a page. The Ajax Control Toolkit is not for everyone. If you are comfortable writing JavaScript then I recommend that you investigate using jQuery plugins instead of the Ajax Control Toolkit. However, if you are a Web Forms developer and you don’t want to get your hands dirty writing JavaScript, then the Ajax Control Toolkit is a great solution. The Ajax Control Toolkit is Vast The Ajax Control Toolkit consists of 40 controls. That’s a lot of controls (For the sake of comparison, jQuery UI consists of only 8 controls – those slackers J). Furthermore, developers expect the Ajax Control Toolkit to work on browsers both old and new. For example, people expect the Ajax Control Toolkit to work with Internet Explorer 6 and Internet Explorer 9 and every version of Internet Explorer in between. People also expect the Ajax Control Toolkit to work on the latest versions of Mozilla Firefox, Apple Safari, and Google Chrome. And, people expect the Ajax Control Toolkit to work with different operating systems. Yikes, that is a lot of combinations. The biggest challenge which my company faces in supporting the Ajax Control Toolkit is ensuring that the Ajax Control Toolkit works across all of these different browsers and operating systems. Testing, Testing, Testing Because we wanted to ensure that we could easily test the Ajax Control Toolkit with different browsers, the very first thing that we did was to set up a dedicated testing server. The dedicated server -- named Schizo -- hosts 4 virtual machines so that we can run Internet Explorer 6, Internet Explorer 7, Internet Explorer 8, and Internet Explorer 9 at the same time (We also use the virtual machines to host the latest versions of Firefox, Chrome, Opera, and Safari). The five developers on our team (plus me) can each publish to a separate FTP website on the testing server. That way, we can quickly test how changes to the Ajax Control Toolkit affect different browsers. QUnit Tests for the Ajax Control Toolkit Introducing regressions – introducing new bugs when trying to fix existing bugs – is the concern which prevents me from sleeping well at night. There are so many people using the Ajax Control Toolkit in so many unique scenarios, that it is difficult to make improvements to the Ajax Control Toolkit without introducing regressions. In order to avoid regressions, we decided early on that it was extremely important to build good test coverage for the 40 controls in the Ajax Control Toolkit. We’ve been focusing a lot of energy on building automated JavaScript unit tests which we can use to help us discover regressions. We decided to write the unit tests with the QUnit test framework. We picked QUnit because it is quickly becoming the standard unit testing framework in the JavaScript world. For example, it is the unit testing framework used by the jQuery team, the jQuery UI team, and many jQuery UI plugin developers. We had to make several enhancements to the QUnit framework in order to test the Ajax Control Toolkit. For example, QUnit does not support tests which include postbacks. We modified the QUnit framework so that it works with IFrames so we could perform postbacks in our automated tests. At this point, we have written hundreds of QUnit tests. For example, we have written 135 QUnit tests for the Accordion control. The QUnit tests are included with the Ajax Control Toolkit source code in a project named AjaxControlToolkit.Tests. You can run all of the QUnit tests contained in the project by opening the Default.aspx page. Automating the QUnit Tests across Multiple Browsers Automated tests are useless if no one ever runs them. In order for the QUnit tests to be useful, we needed an easy way to run the tests automatically against a matrix of browsers. We wanted to run the unit tests against Internet Explorer 6, Internet Explorer 7, Internet Explorer 8, Internet Explorer 9, Firefox, Chrome, and Safari automatically. Expecting a developer to run QUnit tests against every browser after every check-in is just too much to expect. It takes 20 seconds to run the Accordion QUnit tests. We are testing against 8 browsers. That would require the developer to open 8 browsers and wait for the results after each change in code. Too much work. Therefore, we built a JavaScript Test Server. Our JavaScript Test Server project was inspired by John Resig’s TestSwarm project. The JavaScript Test Server runs our QUnit tests in a swarm of browsers (running on different operating systems) automatically. Here’s how the JavaScript Test Server works: 1. We created an ASP.NET page named RunTest.aspx that constantly polls the JavaScript Test Server for a new set of QUnit tests to run. After the RunTest.aspx page runs the QUnit tests, the RunTest.aspx records the test results back to the JavaScript Test Server. 2. We opened the RunTest.aspx page on instances of Internet Explorer 6, Internet Explorer 7, Internet Explorer 8, Internet Explorer 9, FireFox, Chrome, Opera, Google, and Safari. Now that we have the JavaScript Test Server setup, we can run all of our QUnit tests against all of the browsers which we need to support with a single click of a button. A New Release of the Ajax Control Toolkit Each Month The Ajax Control Toolkit Issue Tracker contains over one thousand five hundred open issues and feature requests. So we have plenty of work on our plates J At CodePlex, anyone can vote for an issue to be fixed. Originally, we planned to fix issues in order of their votes. However, we quickly discovered that this approach was inefficient. Constantly switching back and forth between different controls was too time-consuming. It takes time to re-familiarize yourself with a control. Instead, we decided to focus on two or three controls each month and really focus on fixing the issues with those controls. This way, we can fix sets of related issues and avoid the randomization caused by context switching. Our team works in monthly sprints. We plan to do another release of the Ajax Control Toolkit each and every month. So far, we have competed one release of the Ajax Control Toolkit which was released on April 1, 2011. We plan to release a new version in early May. Conclusion Fortunately, I work with a team of smart developers. We currently have 5 developers working on the Ajax Control Toolkit (not full-time, they are also building two very cool ASP.NET MVC applications). All the developers who work on our team are required to have strong JavaScript, jQuery, and ASP.NET MVC skills. In the interest of being as transparent as possible about our work on the Ajax Control Toolkit, I plan to blog frequently about our team’s ongoing work. In my next blog entry, I plan to write about the two Ajax Control Toolkit controls which are the focus of our work for next release.

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  • Tips on installing Visual Studio 2010 SP1

    - by Jon Galloway
    Visual Studio SP1 went up on MSDN downloads (here) on March 8, and will be released publicly on March 10 here. Release announcements: Soma: Visual Studio 2010 enhancements Jason Zander: Announcing Visual Studio 2010 Service Pack 1 I started on this post with tips on installing VS2010 SP1 when I realized I’ve been writing these up for Visual Studio and .NET framework SP releases for a while (e.g. VS2008 / .NET 3.5 SP1 post, VS2005 SP1 post). Looking back the years of Visual Studio SP installs (and remembering when we’d get up to SP6 for a Visual Studio release), I’m happy to see that it just keeps getting easier. Service Packs are a lot less finicky about requiring beta software to be uninstalled, install more quickly, and are just generally a lot less scary. If I can’t have a jetpack, at least my future provided me faster, easier service packs. Disclaimer: These tips are just general things I've picked up over the years. I don't have any inside knowledge here. If you see anything wrong, be sure to let me know in the comments. You may want to check the readme file before installing - it's short, and it's in that new-fangled HTML format. On with the tips! Before starting, uninstall Visual Studio features you don't use Visual Studio service packs (and other Microsoft service packs as well) install patches for the specific features you’ve got installed. This is a big reason to always do a custom install when you first install Visual Studio, but it’s not difficult to update your existing installation. Here’s the quick way to do that: Tap the windows key and type “add or remove programs” and press enter (or click on the “Add or remove programs” link if you must).   Type “Visual Studio 2010” in the search box in the upper right corner, click on the Visual Studio program (the one with the VS infinity looking logo) and click on Uninstall/Change. Click on Add or Remove Features The next part’s up to you – what features do you actually use? I’ve been doing primarily ASP.NET MVC development in C# lately, so I selected Visual C# and Visual Web Developer. Remember that you can install features later if needed, and can also install the express versions if you want. Selecting everything just because it’s there - or you paid for it – means that you install updates for everything, every time. When you’ve made your changes, click on the Update button to uninstall unused features. Shut down all instances of Visual Studio It probably goes without saying that you should close a program down before installing it, partly to avoid the file-in-use-reboot-after-install horror. Additional "hunch / works on my machine" quality tip: On one computer I saw a note in the setup log about Visual Studio a prompt for user input to close Visual Studio, although I never saw the prompt. Just to  be sure, I'd personally open up Task Manager and kill any devenv.exe processes I saw running, as it couldn't hurt. Use the web installer I use the Web Installers whenever possible. There’s no point in downloading the DVD unless you’re doing multiple installs or won’t have internet access. The DVD IS is 1.5GB, since it needs to be able to service every possible supported installation option on both x86 and x64. The web installer is 776 KB (smaller than calc.exe), so you can start the installation right away. Like other web installers, the real benefit is that it only installs the updates you need (hence the reason for step 1 – uninstalling unused components). Instead of 1.5GB, my download was roughly 530MB. If you’re installing from MSDN (this link takes you right to the Visual Studio installs), select the first one on the list: The first step in the installation process is to analyze the machine configuration and tell you what needs to be installed. Since I've trimmed down my features, that's a pretty short list. The time's not far off where I may not install SQL Server on my dev machines, just using SQL Server Compact - that would shorten the list further. When I hit next, you can see that the download size has shrunk considerably. When I start the install, note that the installation begins while other components are downloading - another benefit of the web install. On my mid-range desktop machine, the install took 25 minutes. What if it takes longer? According to Heath Stewart (Visual Studio installer guru), average SP1 installs take roughly 45 minutes. An installation which takes hours to complete may be a sign of a problem: see his post Visual Studio 2010 Service Pack 1 installing for over 2 hours could be a sign of a problem. Why so long? Yes, even 25 minutes is a while. Heath's got another blog post explaining why the update can take longer than the initial install (see: A patch may take as long or longer to install than the target product) which explains all the additional steps and complexities a patch needs to deal with, as well as some mitigation steps that deployment authors can take to mitigate the impact. Other things to know about Visual Studio 2010 SP1 Installs over Visual Studio 2010 SP1 Beta That's nice. Previous Visual Studio versions did a number of annoying things when you installed SP's over beta's - fail with weird errors, get part way through and tell you needed to cancel and uninstall first, etc. I've installed this on two machines that had random beta stuff installed without tears. That Readme file you didn't read I mentioned the readme file earlier (http://go.microsoft.com/fwlink/?LinkId=210711 ). Some interesting things I picked up in there: 2.1.3. Visual Studio 2010 Service Pack 1 installation may fail when a USB drive or other removeable drive is connected 2.1.4. Visual Studio must be restarted after Visual Studio 2010 SP1 tooling for SQL Server Compact (Compact) 4.0 is installed 2.2.1. If Visual Studio 2010 Service Pack 1 is uninstalled, Visual Studio 2010 must be reinstalled to restore certain components 2.2.2. If Visual Studio 2010 Service Pack 1 is uninstalled, Visual Studio 2010 must be reinstalled before SP1 can be installed again 2.4.3.1. Async CTP If you installed the pre-SP1 version of Async CTP but did not uninstall it before you installed Visual Studio 2010 SP1, then your computer will be in a state in which the version of the C# compiler in the .NET Framework does not match the C# compiler in Visual Studio. To resolve this issue: After you install Visual Studio 2010 SP1, reinstall the SP1 version of the Async CTP from here. Hardware acceleration for Visual Studio is disabled on Windows XP Visual Studio 2010 SP1 disables hardware acceleration when running on Windows XP (only on XP). You can turn it back on in the Visual Studio options, under Environment / General, as shown below. See Jason Zander's post titled Performance Troubleshooting Article and VS2010 SP1 Change.

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  • SQL Server and Hyper-V Dynamic Memory Part 3

    - by SQLOS Team
    In parts 1 and 2 of this series we looked at the basics of Hyper-V Dynamic Memory and SQL Server memory management. In this part Serdar looks at configuration guidelines for SQL Server memory management. Part 3: Configuration Guidelines for Hyper-V Dynamic Memory and SQL Server Now that we understand SQL Server Memory Management and Hyper-V Dynamic Memory basics, let’s take a look at general configuration guidelines in order to utilize benefits of Hyper-V Dynamic Memory in your SQL Server VMs. Requirements Host Operating System Requirements Hyper-V Dynamic Memory feature is introduced with Windows Server 2008 R2 SP1. Therefore in order to use Dynamic Memory for your virtual machines, you need to have Windows Server 2008 R2 SP1 or Microsoft Hyper-V Server 2008 R2 SP1 in your Hyper-V host. Guest Operating System Requirements In addition to this Dynamic Memory is only supported in Standard, Web, Enterprise and Datacenter editions of windows running inside VMs. Make sure that your VM is running one of these editions. For additional requirements on each operating system see “Dynamic Memory Configuration Guidelines” here. SQL Server Requirements All versions of SQL Server support Hyper-V Dynamic Memory. However, only certain editions of SQL Server are aware of dynamically changing system memory. To have a truly dynamic environment for your SQL Server VMs make sure that you are running one of the SQL Server editions listed below: ·         SQL Server 2005 Enterprise ·         SQL Server 2008 Enterprise / Datacenter Editions ·         SQL Server 2008 R2 Enterprise / Datacenter Editions Configuration guidelines for other versions of SQL Server are covered below in the FAQ section. Guidelines for configuring Dynamic Memory Parameters Here is how to configure Dynamic Memory for your SQL VMs in a nutshell: Hyper-V Dynamic Memory Parameter Recommendation Startup RAM 1 GB + SQL Min Server Memory Maximum RAM > SQL Max Server Memory Memory Buffer % 5 Memory Weight Based on performance needs   Startup RAM In order to ensure that your SQL Server VMs can start correctly, ensure that Startup RAM is higher than configured SQL Min Server Memory for your VMs. Otherwise SQL Server service will need to do paging in order to start since it will not be able to see enough memory during startup. Also note that Startup Memory will always be reserved for your VMs. This will guarantee a certain level of performance for your SQL Servers, however setting this too high will limit the consolidation benefits you’ll get out of your virtualization environment. Maximum RAM This one is obvious. If you’ve configured SQL Max Server Memory for your SQL Server, make sure that Dynamic Memory Maximum RAM configuration is higher than this value. Otherwise your SQL Server will not grow to memory values higher than the value configured for Dynamic Memory. Memory Buffer % Memory buffer configuration is used to provision file cache to virtual machines in order to improve performance. Due to the fact that SQL Server is managing its own buffer pool, Memory Buffer setting should be configured to the lowest value possible, 5%. Configuring a higher memory buffer will prevent low resource notifications from Windows Memory Manager and it will prevent reclaiming memory from SQL Server VMs. Memory Weight Memory weight configuration defines the importance of memory to a VM. Configure higher values for the VMs that have higher performance requirements. VMs with higher memory weight will have more memory under high memory pressure conditions on your host. Questions and Answers Q1 – Which SQL Server memory model is best for Dynamic Memory? The best SQL Server model for Dynamic Memory is “Locked Page Memory Model”. This memory model ensures that SQL Server memory is never paged out and it’s also adaptive to dynamically changing memory in the system. This will be extremely useful when Dynamic Memory is attempting to remove memory from SQL Server VMs ensuring no SQL Server memory is paged out. You can find instructions on configuring “Locked Page Memory Model” for your SQL Servers here. Q2 – What about other SQL Server Editions, how should I configure Dynamic Memory for them? Other editions of SQL Server do not adapt to dynamically changing environments. They will determine how much memory they should allocate during startup and don’t change this value afterwards. Therefore make sure that you configure a higher startup memory for your VM because that will be all the memory that SQL Server utilize Tune Maximum Memory and Memory Buffer based on the other workloads running on the system. If there are no other workloads consider using Static Memory for these editions. Q3 – What if I have multiple SQL Server instances in a VM? Having multiple SQL Server instances in a VM is not a general recommendation for predictable performance, manageability and isolation. In order to achieve a predictable behavior make sure that you configure SQL Min Server Memory and SQL Max Server Memory for each instance in the VM. And make sure that: ·         Dynamic Memory Startup Memory is greater than the sum of SQL Min Server Memory values for the instances in the VM ·         Dynamic Memory Maximum Memory is greater than the sum of SQL Max Server Memory values for the instances in the VM Q4 – I’m using Large Page Memory Model for my SQL Server. Can I still use Dynamic Memory? The short answer is no. SQL Server does not dynamically change its memory size when configured with Large Page Memory Model. In virtualized environments Hyper-V provides large page support by default. Most of the time, Large Page Memory Model doesn’t bring any benefits to a SQL Server if it’s running in virtualized environments. Q5 – How do I monitor SQL performance when I’m trying Dynamic Memory on my VMs? Use the performance counters below to monitor memory performance for SQL Server: Process - Working Set: This counter is available in the VM via process performance counters. It represents the actual amount of physical memory being used by SQL Server process in the VM. SQL Server – Buffer Cache Hit Ratio: This counter is available in the VM via SQL Server counters. This represents the paging being done by SQL Server. A rate of 90% or higher is desirable. Conclusion These blog posts are a quick start to a story that will be developing more in the near future. We’re still continuing our testing and investigations to provide more detailed configuration guidelines with example performance numbers with a white paper in the upcoming months. Now it’s time to give SQL Server and Hyper-V Dynamic Memory a try. Use this guidelines to kick-start your environment. See what you think about it and let us know of your experiences. - Serdar Sutay Originally posted at http://blogs.msdn.com/b/sqlosteam/

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  • An Alphabet of Eponymous Aphorisms, Programming Paradigms, Software Sayings, Annoying Alliteration

    - by Brian Schroer
    Malcolm Anderson blogged about “Einstein’s Razor” yesterday, which reminded me of my favorite software development “law”, the name of which I can never remember. It took much Wikipedia-ing to find it (Hofstadter’s Law – see below), but along the way I compiled the following list: Amara’s Law: We tend to overestimate the effect of a technology in the short run and underestimate the effect in the long run. Brook’s Law: Adding manpower to a late software project makes it later. Clarke’s Third Law: Any sufficiently advanced technology is indistinguishable from magic. Law of Demeter: Each unit should only talk to its friends; don't talk to strangers. Einstein’s Razor: “Make things as simple as possible, but not simpler” is the popular paraphrase, but what he actually said was “It can scarcely be denied that the supreme goal of all theory is to make the irreducible basic elements as simple and as few as possible without having to surrender the adequate representation of a single datum of experience”, an overly complicated quote which is an obvious violation of Einstein’s Razor. (You can tell by looking at a picture of Einstein that the dude was hardly an expert on razors or other grooming apparati.) Finagle's Law of Dynamic Negatives: Anything that can go wrong, will—at the worst possible moment. - O'Toole's Corollary: The perversity of the Universe tends towards a maximum. Greenspun's Tenth Rule: Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp. (Morris’s Corollary: “…including Common Lisp”) Hofstadter's Law: It always takes longer than you expect, even when you take into account Hofstadter's Law. Issawi’s Omelet Analogy: One cannot make an omelet without breaking eggs - but it is amazing how many eggs one can break without making a decent omelet. Jackson’s Rules of Optimization: Rule 1: Don't do it. Rule 2 (for experts only): Don't do it yet. Kaner’s Caveat: A program which perfectly meets a lousy specification is a lousy program. Liskov Substitution Principle (paraphrased): Functions that use pointers or references to base classes must be able to use objects of derived classes without knowing it Mason’s Maxim: Since human beings themselves are not fully debugged yet, there will be bugs in your code no matter what you do. Nils-Peter Nelson’s Nil I/O Rule: The fastest I/O is no I/O.    Occam's Razor: The simplest explanation is usually the correct one. Parkinson’s Law: Work expands so as to fill the time available for its completion. Quentin Tarantino’s Pie Principle: “…you want to go home have a drink and go and eat pie and talk about it.” (OK, he was talking about movies, not software, but I couldn’t find a “Q” quote about software. And wouldn’t it be cool to write a program so great that the users want to eat pie and talk about it?) Raymond’s Rule: Computer science education cannot make anybody an expert programmer any more than studying brushes and pigment can make somebody an expert painter.  Sowa's Law of Standards: Whenever a major organization develops a new system as an official standard for X, the primary result is the widespread adoption of some simpler system as a de facto standard for X. Turing’s Tenet: We shall do a much better programming job, provided we approach the task with a full appreciation of its tremendous difficulty, provided that we respect the intrinsic limitations of the human mind and approach the task as very humble programmers.  Udi Dahan’s Race Condition Rule: If you think you have a race condition, you don’t understand the domain well enough. These rules didn’t exist in the age of paper, there is no reason for them to exist in the age of computers. When you have race conditions, go back to the business and find out actual rules. Van Vleck’s Kvetching: We know about as much about software quality problems as they knew about the Black Plague in the 1600s. We've seen the victims' agonies and helped burn the corpses. We don't know what causes it; we don't really know if there is only one disease. We just suffer -- and keep pouring our sewage into our water supply. Wheeler’s Law: All problems in computer science can be solved by another level of indirection... Except for the problem of too many layers of indirection. Wheeler also said “Compatibility means deliberately repeating other people's mistakes.”. The Wrong Road Rule of Mr. X (anonymous): No matter how far down the wrong road you've gone, turn back. Yourdon’s Rule of Two Feet: If you think your management doesn't know what it's doing or that your organisation turns out low-quality software crap that embarrasses you, then leave. Zawinski's Law of Software Envelopment: Every program attempts to expand until it can read mail. Zawinski is also responsible for “Some people, when confronted with a problem, think 'I know, I'll use regular expressions.' Now they have two problems.” He once commented about X Windows widget toolkits: “Using these toolkits is like trying to make a bookshelf out of mashed potatoes.”

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  • On StringComparison Values

    - by Jesse
    When you use the .NET Framework’s String.Equals and String.Compare methods do you use an overloStringComparison enumeration value? If not, you should be because the value provided for that StringComparison argument can have a big impact on the results of your string comparison. The StringComparison enumeration defines values that fall into three different major categories: Culture-sensitive comparison using a specific culture, defaulted to the Thread.CurrentThread.CurrentCulture value (StringComparison.CurrentCulture and StringComparison.CurrentCutlureIgnoreCase) Invariant culture comparison (StringComparison.InvariantCulture and StringComparison.InvariantCultureIgnoreCase) Ordinal (byte-by-byte) comparison of  (StringComparison.Ordinal and StringComparison.OrdinalIgnoreCase) There is a lot of great material available that detail the technical ins and outs of these different string comparison approaches. If you’re at all interested in the topic these two MSDN articles are worth a read: Best Practices For Using Strings in the .NET Framework: http://msdn.microsoft.com/en-us/library/dd465121.aspx How To Compare Strings: http://msdn.microsoft.com/en-us/library/cc165449.aspx Those articles cover the technical details of string comparison well enough that I’m not going to reiterate them here other than to say that the upshot is that you typically want to use the culture-sensitive comparison whenever you’re comparing strings that were entered by or will be displayed to users and the ordinal comparison in nearly all other cases. So where does that leave the invariant culture comparisons? The “Best Practices For Using Strings in the .NET Framework” article has the following to say: “On balance, the invariant culture has very few properties that make it useful for comparison. It does comparison in a linguistically relevant manner, which prevents it from guaranteeing full symbolic equivalence, but it is not the choice for display in any culture. One of the few reasons to use StringComparison.InvariantCulture for comparison is to persist ordered data for a cross-culturally identical display. For example, if a large data file that contains a list of sorted identifiers for display accompanies an application, adding to this list would require an insertion with invariant-style sorting.” I don’t know about you, but I feel like that paragraph is a bit lacking. Are there really any “real world” reasons to use the invariant culture comparison? I think the answer to this question is, “yes”, but in order to understand why we should first think about what the invariant culture comparison really does. The invariant culture comparison is really just a culture-sensitive comparison using a special invariant culture (Michael Kaplan has a great post on the history of the invariant culture on his blog: http://blogs.msdn.com/b/michkap/archive/2004/12/29/344136.aspx). This means that the invariant culture comparison will apply the linguistic customs defined by the invariant culture which are guaranteed not to differ between different machines or execution contexts. This sort of consistently does prove useful if you needed to maintain a list of strings that are sorted in a meaningful and consistent way regardless of the user viewing them or the machine on which they are being viewed. Example: Prototype Names Let’s say that you work for a large multi-national toy company with branch offices in 10 different countries. Each year the company would work on 15-25 new toy prototypes each of which is assigned a “code name” while it is under development. Coming up with fun new code names is a big part of the company culture that everyone really enjoys, so to be fair the CEO of the company spent a lot of time coming up with a prototype naming scheme that would be fun for everyone to participate in, fair to all of the different branch locations, and accessible to all members of the organization regardless of the country they were from and the language that they spoke. Each new prototype will get a code name that begins with a letter following the previously created name using the alphabetical order of the Latin/Roman alphabet. Each new year prototype names would start back at “A”. The country that leads the prototype development effort gets to choose the name in their native language. (An appropriate Romanization system will be used for countries where the primary language is not written in the Latin/Roman alphabet. For example, the Pinyin system could be used for Chinese). To avoid repeating names, a list of all current and past prototype names will be maintained on each branch location’s company intranet site. Assuming that maintaining a single pre-sorted list is not feasible among all of the highly distributed intranet implementations, what string comparison method would you use to sort each year’s list of prototype names so that the list is both meaningful and consistent regardless of the country within which the list is being viewed? Sorting the list with a culture-sensitive comparison using the default configured culture on each country’s intranet server the list would probably work most of the time, but subtle differences between cultures could mean that two different people would see a list that was sorted slightly differently. The CEO wants the prototype names to be a unifying aspect of company culture and is adamant that everyone see the the same list sorted in the same order and there’s no way to guarantee a consistent sort across different cultures using the culture-sensitive string comparison rules. The culture-sensitive sort would produce a meaningful list for the specific user viewing it, but it wouldn’t always be consistent between different users. Sorting with the ordinal comparison would certainly be consistent regardless of the user viewing it, but would it be meaningful? Let’s say that the current year’s prototype name list looks like this: Antílope (Spanish) Babouin (French) Cahoun (Czech) Diamond (English) Flosse (German) If you were to sort this list using ordinal rules you’d end up with: Antílope Babouin Diamond Flosse Cahoun This sort is no good because the entry for “C” appears the bottom of the list after “F”. This is because the Czech entry for the letter “C” makes use of a diacritic (accent mark). The ordinal string comparison does a byte-by-byte comparison of the code points that make up each character in the string and the code point for the “C” with the diacritic mark is higher than any letter without a diacritic mark, which pushes that entry to the bottom of the sorted list. The CEO wants each country to be able to create prototype names in their native language, which means we need to allow for names that might begin with letters that have diacritics, so ordinal sorting kills the meaningfulness of the list. As it turns out, this situation is actually well-suited for the invariant culture comparison. The invariant culture accounts for linguistically relevant factors like the use of diacritics but will provide a consistent sort across all machines that perform the sort. Now that we’ve walked through this example, the following line from the “Best Practices For Using Strings in the .NET Framework” makes a lot more sense: One of the few reasons to use StringComparison.InvariantCulture for comparison is to persist ordered data for a cross-culturally identical display That line describes the prototype name example perfectly: we need a way to persist ordered data for a cross-culturally identical display. While this example is 100% made-up, I think it illustrates that there are indeed real-world situations where the invariant culture comparison is useful.

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  • Can Microsoft Build Appliances?

    - by andrewbrust
    Billy Hollis, my Visual Studio Live! colleague and fellow Microsoft Regional Director said recently, and I am paraphrasing, that the computing world, especially on the consumer side, has shifted from one of building hardware and software that makes things possible to do, to building products and technologies that make things easy to do.  Billy crystalized things perfectly, as he often does. In this new world of “easy to do,” Apple has done very well and Microsoft has struggled.  In the old world, customers wanted a Swiss Army Knife, with the most gimmicks and gadgets possible.  In the new world, people want elegantly cutlery.  They may want cake cutters and utility knives too, but they don’t want one device that works for all three tasks.  People don’t want tools, they want utensils.  People don’t want machines.  They want appliances. Microsoft Appliances: They Do Exist Microsoft has built a few appliance-like devices.  I would say XBox 360 is an appliance,  It’s versatile, mind you, but it’s the kind of thing you plug in, turn on and use, as opposed to set-up, tune, and open up to upgrade the internals.  Windows Phone 7 is an appliance too.  It’s a true smartphone, unlike Windows Mobile which was a handheld computer with a radio stack.  Zune is an appliance too, and a nice one.  It hasn’t attained much traction in the market, but that’s probably because the seminal consumer computing appliance -- the iPod – got there so much more quickly. In the embedded world, Mediaroom, Microsoft’s set-top product for the cable industry (used by AT&T U-Verse and others) is an appliance.  So is Microsoft’s Sync technology, used in Ford automobiles.  Even on the enterprise side, Microsoft has an appliance: SQL Server Parallel Data Warehouse Edition (PDW) combines Microsoft software with select OEMs’ server, networking and storage hardware.  You buy the appliance units from the OEMs, plug them in, connect them and go. I would even say that Bing is an appliance.  Not in the hardware sense, mind you.  But from the software perspective, it’s a single-purpose product that you visit or run, use and then move on.  You don’t have to install it (except the iOS and Android native apps where it’s pretty straightforward), you don’t have to customize it, you don’t have to program it.  Basically, you just use it. Microsoft Appliances that Should Exist But Microsoft builds a bunch of things that are not appliances.  Media Center is not an appliance, and it most certainly should be.  Instead, it’s an app that runs on Windows 7.  It runs full-screen and you can use this configuration to conceal the fact that Windows is under it, but eventually something will cause you to abandon that masquerade (like Patch Tuesday). The next version of Windows Home Server won’t, in my opinion, be an appliance either.  Now that the Drive Extender technology is gone, and users can’t just add and remove drives into and from a single storage pool, the product is much more like a IT server and less like an appliance-premised one.  Much has been written about this decision by Microsoft.  I’ll just sum it up in one word: pity. Microsoft doesn’t have anything remotely appliance-like in the tablet category, either.  Until it does, it likely won’t have much market share in that space either.  And of course, the bulk of Microsoft’s product catalog on the business side is geared to enterprise machines and not personal appliances. Appliance DNA: They Gotta Have It. The consumerization of IT is real, because businesspeople are consumers too.  They appreciate the fit and finish of appliances at home, and they increasingly feel entitled to have it at work too.  Secure and reliable push email in a smartphone is necessary, but it isn’t enough.  People want great apps and a pleasurable user experience too.  The full Microsoft Office product is needed at work, but a PC with a keyboard and mouse, or maybe a touch screen that uses a stylus (or requires really small fingers), to run Office isn’t enough either.  People want a flawless touch experience available for the times they want to read and take quick notes.  Until Microsoft realizes this fully and internalizes it, it will suffer defeats in the consumer market and even setbacks in the business market.  Think about how slow the Office upgrade cycle is…now imagine if the next version of Office had a first-class alternate touch UI and consider the possible acceleration in adoption rates. Can Microsoft make the appliance switch?  Can the appliance mentality become pervasive at the company?  Can Microsoft hasten its release cycles dramatically and shed the “some assembly required” paradigm upon which many of its products are based?  Let’s face it, the chances that Microsoft won’t make this transition are significant. But there are also encouraging signs, and they should not be ignored.  The appliances we have already discussed, especially Xbox, Zune and Windows Phone 7, are the most obvious in this regard.  The fact that SQL Server has an appliance SKU now is a more subtle but perhaps also more significant outcome, because that product sits so smack in the middle of Microsoft’s enterprise stack.  Bing is encouraging too, especially given its integrated travel, maps and augmented reality capabilities.  As Bing gains market share, Microsoft has tangible proof that it can transform and win, even when everyone outside the company, and many within it, would bet otherwise. That Great Big Appliance in the Sky Perhaps the most promising (and evolving) proof points toward the appliance mentality, though, are Microsoft’s cloud offerings -- Azure and BPOS/Office 365.  While the cloud does not represent a physical appliance (quite the opposite in fact) its ability to make acquisition, deployment and use of technology simple for the user is absolutely an embodiment of the appliance mentality and spirit.  Azure is primarily a platform as a service offering; it doesn’t just provide infrastructure.  SQL Azure does likewise for databases.  And Office 365 does likewise for SharePoint, Exchange and Lync. You don’t administer, tune and manage servers; instead, you create databases or site collections or mailboxes and start using them. Upgrades come automatically, and it seems like releases will come more frequently.  Fault tolerance and content distribution is just there.  No muss.  No fuss.  You use these services; you don’t have to set them up and think about them.  That’s how appliances work.  To me, these signs point out that Microsoft has the full capability of transforming itself.  But there’s a lot of work ahead.  Microsoft may say they’re “all in” on the cloud, but the majority of the company is still oriented around its old products and models.  There needs to be a wholesale cultural transformation in Redmond.  It can happen, but product management, program management, the field and executive ranks must unify in the effort. So must partners, and even customers.  New leaders must rise up and Microsoft must be able to see itself as a winner.  If Microsoft does this, it could lock-in decades of new success, and be a standard business school case study for doing so.  If not, the company will have missed an opportunity, and may see its undoing.

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