Search Results

Search found 7473 results on 299 pages for 'usage statistics'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 17/299 | < Previous Page | 13 14 15 16 17 18 19 20 21 22 23 24  | Next Page >

  • Even distribution through a chain of resources

    - by ClosetGeek
    I'm working on an algorithm which routes tasks through a chain of distributed resources based on a hash (or random number). For example, say you have 10 gateways into a service which distribute tasks to 1000 handlers through 100 queues. 10,000 connected clients are expected to be connected to gateways at any given time (numbers are very general to keep it simple). Thats 10,000 clients 10 gateways (producers) 100 queues 1000 workers/handlers (consumers) The flow of each task is client-gateway-queue-worker Each client will have it's own hash/number which is used to route each task from the client to the same worker each time, with each task going through the same gateway and queue each time. Yet the algorithm handles distribution evenly, meaning each gateway, queue, and worker will have an even workload. My question is what exactly would this be called? Does such a thing already exist? This started off as a DHT, but I realized that DHTs can't do exactly what I need, so I started from scratch.

    Read the article

  • SQL SERVER – Solution – Challenge – Puzzle – Usage of FAST Hint

    - by pinaldave
    Earlier I had posted quick puzzle and I had received wonderful response to the same from Brad Schulz. Today we will go over the solution. The puzzle was posted here: SQL SERVER – Challenge – Puzzle – Usage of FAST Hint The question was in what condition the hint FAST will be useful. In the response to this puzzle blog post here is what SQL Server Expert Brad Schulz has pointed me to his blog post where he explain how FAST hint can be useful. I strongly recommend to read his blog post over here. With the permission of the Brad, I am reproducing following queries here. He has come up with example where FAST hint improves the performance. USE AdventureWorks GO DECLARE @DesiredDateAtMidnight DATETIME = '20010709' DECLARE @NextDateAtMidnight DATETIME = DATEADD(DAY,1,@DesiredDateAtMidnight) -- Query without FAST SELECT OrderID=h.SalesOrderID ,h.OrderDate ,h.TerritoryID ,TerritoryName=t.Name ,c.CardType ,c.CardNumber ,CardExpire=RIGHT(STR(100+ExpMonth),2)+'/'+STR(ExpYear,4) ,h.TotalDue FROM Sales.SalesOrderHeader h LEFT JOIN Sales.SalesTerritory t ON h.TerritoryID=t.TerritoryID LEFT JOIN Sales.CreditCard c ON h.CreditCardID=c.CreditCardID WHERE OrderDate>=@DesiredDateAtMidnight AND OrderDate<@NextDateAtMidnight ORDER BY h.SalesOrderID; -- Query with FAST(10) SELECT OrderID=h.SalesOrderID ,h.OrderDate ,h.TerritoryID ,TerritoryName=t.Name ,c.CardType ,c.CardNumber ,CardExpire=RIGHT(STR(100+ExpMonth),2)+'/'+STR(ExpYear,4) ,h.TotalDue FROM Sales.SalesOrderHeader h LEFT JOIN Sales.SalesTerritory t ON h.TerritoryID=t.TerritoryID LEFT JOIN Sales.CreditCard c ON h.CreditCardID=c.CreditCardID WHERE OrderDate>=@DesiredDateAtMidnight AND OrderDate<@NextDateAtMidnight ORDER BY h.SalesOrderID OPTION(FAST 10) Now when you check the execution plan for the same, you will find following visible difference. You will find query with FAST returns results with much lower cost. Thank you Brad for excellent post and teaching us something. I request all of you to read original blog post written by Brad for much more information. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, Readers Contribution, Readers Question, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • SYS2 Scripts Updated – Scripts to monitor database backup, database space usage and memory grants now available

    - by Davide Mauri
    I’ve just released three new scripts of my “sys2” script collection that can be found on CodePlex: Project Page: http://sys2dmvs.codeplex.com/ Source Code Download: http://sys2dmvs.codeplex.com/SourceControl/changeset/view/57732 The three new scripts are the following sys2.database_backup_info.sql sys2.query_memory_grants.sql sys2.stp_get_databases_space_used_info.sql Here’s some more details: database_backup_info This script has been made to quickly check if and when backup was done. It will report the last full, differential and log backup date and time for each database. Along with these information you’ll also get some additional metadata that shows if a database is a read-only database and its recovery model: By default it will check only the last seven days, but you can change this value just specifying how many days back you want to check. To analyze the last seven days, and list only the database with FULL recovery model without a log backup select * from sys2.databases_backup_info(default) where recovery_model = 3 and log_backup = 0 To analyze the last fifteen days, and list only the database with FULL recovery model with a differential backup select * from sys2.databases_backup_info(15) where recovery_model = 3 and diff_backup = 1 I just love this script, I use it every time I need to check that backups are not too old and that t-log backup are correctly scheduled. query_memory_grants This is just a wrapper around sys.dm_exec_query_memory_grants that enriches the default result set with the text of the query for which memory has been granted or is waiting for a memory grant and, optionally, its execution plan stp_get_databases_space_used_info This is a stored procedure that list all the available databases and for each one the overall size, the used space within that size, the maximum size it may reach and the auto grow options. This is another script I use every day in order to be able to monitor, track and forecast database space usage. As usual feedbacks and suggestions are more than welcome!

    Read the article

  • Why is the root partition on my disk full?

    - by Agmenor
    I installed Ubuntu 12.04 by doing a fresh install where there was previously Ubuntu 11.10. My computer warns me now that my disk is nearly full. After having run apt-get purge, run apt-get autoremove and emptied the Trash can, I still have this problem as shown by this screenshot of Gparted: The disk /dev/sda7 is indeed full. I ran the Disk Usage Analyzer (Baobab) and I am still not sure of what is happening: One of my hypothesis is that when installing Ubuntu 12.04, I didn't configure my disks well and the disk /dev/sda6 is not mounted well as /home. Is this the reason indeed? What should I do to verify this and then to get the things fixed? Here are a few additional details to answer the questions I received (thank you everybody): My home directory is not encrypted. The Backup utility (Déjà Dup) is not set for automatic backups. (I do it myself and manually.) After I mount /dev/sda6, the command df -h gives Filesystem Size Used Avail Use% Mounted on /dev/sda7 244G 221G 12G 96% / udev 3,9G 4,0K 3,9G 1% /dev tmpfs 1,6G 904K 1,6G 1% /run none 5,0M 0 5,0M 0% /run/lock none 3,9G 164K 3,9G 1% /run/shm /dev/sda6 653G 189G 433G 31% /media/8ec2fa69-039b-4c52-ab1b-034d785132a1 (sorry but formatting this into code does not work, for an unknown reason) Thanks to izx's post, I realized /dev/sda6 was not even mounted before. It contains all the documents I used to have when I was running Ubuntu 11.10.

    Read the article

  • improve Collision detection memory usage (blocks with bullets)

    - by Eddy
    i am making a action platform 2D game, something like Megaman. I am using XNA to make it. already made player phisics,collisions, bullets, enemies and AIs, map editor, scorolling X Y camera (about 75% of game is finished ). as i progressed i noticed that my game would be more interesting to play if bullets would be destroyed on collision with regular(stationary ) map blocks, only problem is that if i use my collision detection (each bullet with each block) sometimes it begins to lag(btw if my bullet exits the screen player can see it is removed from bullet list) So how to improve my collision detection so that memory usage would be so high? :) ( on a map 300x300 blocks for example don't think that bigger map should be made); int block = 0; int bulet= 0; bool destroy_bullet = false; while (bulet < bullets.Count) { while (block < blocks.Count) { if (bullets[bulet].P_Bul_rec.Intersects( blocks[block].rect)) {//bullets and block are Lists that holds objects of bullet and block classes //P_Bul_rec just bullet rectangle destroy_bullet = true; } block++; } if (destroy_bullet) { bullets.RemoveAt(bulet); destroy_bullet = false; } else { bulet++; } block = 0; }

    Read the article

  • Software licensing template that gives room for restricting usage to certain industries/uses of software/source

    - by BSara
    *Why this question is not a duplicate of the questions specified as such: I did not ask if there was a license that restricted specific uses and I did not ask if I could rewrite every line of any open source project. I asked very specifically: "Does there exist X? If not, can I Y with Z?". As far as I can tell, the two questions that were specified as duplicates do not answer my specific question. Please remove the duplicate status placed on the question. I'm developing some software that I would like to be "semi" open source. I would like to allow for anyone to use my software/source unless they are using the software/source for certain purposes. For example, I don't want to allow usage of the software/source if it is being used to create, distribute, view or otherwise support pornography, illegal purposes, etc. I'm no lawyer and couldn't ever hope to write a license myself nor do I have to time to figure how to best do this. My question is this: Does there exist a freely available license or a template for a license that I can use to license my software under they conditions explained above just like one can use the Creative Commons licenses? If not, am I allowed to just alter one of Creative Commons licenses to meet my needs?

    Read the article

  • Best Usage of Multiple Computers For a Developer

    - by whaley
    I have two Macbook Pros - both are comparable in hardware. One is a 17" and the other a 15". The 17" has a slightly swifter CPU clock speed, but beyond that the differences are completely negligible. I tried a setup a while back where I had the 17" hooked up to an external monitor in the middle of my desk with the 15" laptop immediately to the right of it, and was using teleport to control the 15" from my 17". All development, terminal usage, etc. etc. was being done on the 17" and the 15" was primarily used for email / IM / IRC... or anything secondary to what I was working on. I have a MobileMe account so preferences were synced, but otherwise I didn't really use anything else to keep the computers in sync (I use dropbox/git but probably not optimally). For reasons I can't put my finger on, this setup never felt quite right. A few things that irked me was the 15" was way under-utlized and the 17" was overutilized having 2 laptops and a 21" monitor all on one desk actually took up lots of desk space and it felt like I had too much to look at. I reverted back to just using the 17" and the external monitor and keeping the 15" around the house (and using it very sparingly). For those of you who are using multiple laptops (or just multiple machines for that matter), I'd like to see setups that work for you for when you have 2 or more machines that gives you optimal productivity and why. I'd like to give this one more shot but with a different approach than my previous - which was using the 15" as a machine for secondary things (communication, reading documentation, etc. etc).

    Read the article

  • Where is my ram?

    - by gsedej
    I have 2GB installed on my machine running Ubuntu 12.04. After some time of use, I see much of my RAM used. The RAM does not free enough even though I closed all my programs. I included 2 screenshots. First is "Gnome system monitor" (all process) and second is "htop" (with sudo), both sorted by memory usage. From both you see, that it's not possible that all running apps takes together 1GB of memory. First 7 biggest programs sum 250, but others are much smaller (all can't sum even 100MB). The cache is 300MB (yellow ||| on htop) and is not included in 1GB used. Also 260MB is already on swap. (which actually makes 1,3GB of used memory) If i start Firefox (or Chrome) with many tabs, it has only 1GB available and not potentially 1,5 GB (assume 0,5GB is for system). When I need more ram, swapping happens. So where is my ram? Which program is using it? How can i free it, to be available for e.g. Firefox? Gnome system monitor htop

    Read the article

  • Why is my disk full?

    - by Agmenor
    I installed Ubuntu 12.04 by doing a fresh install where there was previously Ubuntu 11.10. My computer warns me now that my disk is nearly full. After having run apt-get purge, run apt-get autoremove and emptied the Trash can, I still have this problem as shown by this screenshot of Gparted: The disk /dev/sda7 is indeed full. I ran the Disk Usage Analyzer (Baobab) and I am still not sure of what is happening: One of my hypothesis is that when installing Ubuntu 12.04, I didn't configure my disks well and the disk /dev/sda6 is not mounted well as /home. Is this the reason indeed? What should I do to verify this and then to get the things fixed? Here are a few additional details to answer the questions I received (thank you everybody): My home directory is not encrypted. The Backup utility (Déjà Dup) is not set for automatic backups. (I do it myself and manually.) After I mount /dev/sda6, the command df -h gives Filesystem Size Used Avail Use% Mounted on /dev/sda7 244G 221G 12G 96% / udev 3,9G 4,0K 3,9G 1% /dev tmpfs 1,6G 904K 1,6G 1% /run none 5,0M 0 5,0M 0% /run/lock none 3,9G 164K 3,9G 1% /run/shm /dev/sda6 653G 189G 433G 31% /media/8ec2fa69-039b-4c52-ab1b-034d785132a1 (sorry but formatting this into code does not work, for an unknown reason) Thanks to izx's post, I realized /dev/sda6 was not even mounted before. It contains all the documents I used to have when I was running Ubuntu 11.10.

    Read the article

  • Updating to linux-image-3.2.0-26-generic occupies all disk space

    - by user42228
    I just ran a normal update through the update manager that wanted to update me to linux-image-3.2.0-26-generic. The installation paused halfway with a message that the root was full. I checked the disk usage, and noticed that one of the newly installed files: /lib/modules/3.2.0-26-generic/modules.ccwmap took up 63GB(!). Compared to the previous version: /lib/modules/3.2.0-24-generic/modules.ccwmap that took up only 4KB it seems like something went awfully wrong! As mentioned the update was paused when i ran out of disk space. There is no option in the update dialog to cancel or perform rollback on the update. Is it asking for trouble to kill the update manager? Any ideas as to what went wrong, and what I can do to remedy it? It's only minimal how much space I can free on that partition (without deleting the above mentioned file). If it is any help, the update was paused after this: Examining /etc/kernel/postinst.d. run-parts: executing /etc/kernel/postinst.d/dkms 3.2.0-26-generic /boot/vmlinuz-3.2.0-26-generic

    Read the article

  • Getting a per thread cpu stats

    - by viraptor
    I'm interested in the current usage of cpu - precisely cpu% and wait% - for each thread in a specific application. Is it possible to get that information from somewhere? I know that top can split information per real thread (ones with pid), but it doesn't show the system/user/wait cpu usage split for each of them. I would also like some way to log that info. Do you know any apps (or apis) that can do that?

    Read the article

  • Postfix log.... spam attempt?

    - by luri
    I have some weird entries in my mail.log. What I'd like to ask is if postfix is avoiding correctly (according with the main.cf attached below) what seems to be relay attempts, presumably for spamming, or if I can enhance it's security somehow. Feb 2 11:53:25 MYSERVER postfix/smtpd[9094]: connect from catv-80-99-46-143.catv.broadband.hu[80.99.46.143] Feb 2 11:53:25 MYSERVER postfix/smtpd[9094]: warning: non-SMTP command from catv-80-99-46-143.catv.broadband.hu[80.99.46.143]: GET / HTTP/1.1 Feb 2 11:53:25 MYSERVER postfix/smtpd[9094]: disconnect from catv-80-99-46-143.catv.broadband.hu[80.99.46.143] Feb 2 11:56:45 MYSERVER postfix/anvil[9097]: statistics: max connection rate 1/60s for (smtp:80.99.46.143) at Feb 2 11:53:25 Feb 2 11:56:45 MYSERVER postfix/anvil[9097]: statistics: max connection count 1 for (smtp:80.99.46.143) at Feb 2 11:53:25 Feb 2 11:56:45 MYSERVER postfix/anvil[9097]: statistics: max cache size 1 at Feb 2 11:53:25 Feb 2 12:09:19 MYSERVER postfix/smtpd[9302]: connect from vs148181.vserver.de[62.75.148.181] Feb 2 12:09:19 MYSERVER postfix/smtpd[9302]: warning: non-SMTP command from vs148181.vserver.de[62.75.148.181]: GET / HTTP/1.1 Feb 2 12:09:19 MYSERVER postfix/smtpd[9302]: disconnect from vs148181.vserver.de[62.75.148.181] Feb 2 12:12:39 MYSERVER postfix/anvil[9304]: statistics: max connection rate 1/60s for (smtp:62.75.148.181) at Feb 2 12:09:19 Feb 2 12:12:39 MYSERVER postfix/anvil[9304]: statistics: max connection count 1 for (smtp:62.75.148.181) at Feb 2 12:09:19 Feb 2 12:12:39 MYSERVER postfix/anvil[9304]: statistics: max cache size 1 at Feb 2 12:09:19 Feb 2 14:17:02 MYSERVER postfix/smtpd[10847]: connect from unknown[202.46.129.123] Feb 2 14:17:02 MYSERVER postfix/smtpd[10847]: warning: non-SMTP command from unknown[202.46.129.123]: GET / HTTP/1.1 Feb 2 14:17:02 MYSERVER postfix/smtpd[10847]: disconnect from unknown[202.46.129.123] Feb 2 14:20:22 MYSERVER postfix/anvil[10853]: statistics: max connection rate 1/60s for (smtp:202.46.129.123) at Feb 2 14:17:02 Feb 2 14:20:22 MYSERVER postfix/anvil[10853]: statistics: max connection count 1 for (smtp:202.46.129.123) at Feb 2 14:17:02 Feb 2 14:20:22 MYSERVER postfix/anvil[10853]: statistics: max cache size 1 at Feb 2 14:17:02 Feb 2 20:57:33 MYSERVER postfix/smtpd[18452]: warning: 95.110.224.230: hostname host230-224-110-95.serverdedicati.aruba.it verification failed: Name or service not known Feb 2 20:57:33 MYSERVER postfix/smtpd[18452]: connect from unknown[95.110.224.230] Feb 2 20:57:33 MYSERVER postfix/smtpd[18452]: lost connection after CONNECT from unknown[95.110.224.230] Feb 2 20:57:33 MYSERVER postfix/smtpd[18452]: disconnect from unknown[95.110.224.230] Feb 2 21:00:53 MYSERVER postfix/anvil[18455]: statistics: max connection rate 1/60s for (smtp:95.110.224.230) at Feb 2 20:57:33 Feb 2 21:00:53 MYSERVER postfix/anvil[18455]: statistics: max connection count 1 for (smtp:95.110.224.230) at Feb 2 20:57:33 Feb 2 21:00:53 MYSERVER postfix/anvil[18455]: statistics: max cache size 1 at Feb 2 20:57:33 Feb 2 21:13:44 MYSERVER pop3d: Connection, ip=[::ffff:219.94.190.222] Feb 2 21:13:44 MYSERVER pop3d: LOGIN FAILED, user=admin, ip=[::ffff:219.94.190.222] Feb 2 21:13:50 MYSERVER pop3d: LOGIN FAILED, user=test, ip=[::ffff:219.94.190.222] Feb 2 21:13:56 MYSERVER pop3d: LOGIN FAILED, user=danny, ip=[::ffff:219.94.190.222] Feb 2 21:14:01 MYSERVER pop3d: LOGIN FAILED, user=sharon, ip=[::ffff:219.94.190.222] Feb 2 21:14:07 MYSERVER pop3d: LOGIN FAILED, user=aron, ip=[::ffff:219.94.190.222] Feb 2 21:14:12 MYSERVER pop3d: LOGIN FAILED, user=alex, ip=[::ffff:219.94.190.222] Feb 2 21:14:18 MYSERVER pop3d: LOGIN FAILED, user=brett, ip=[::ffff:219.94.190.222] Feb 2 21:14:24 MYSERVER pop3d: LOGIN FAILED, user=mike, ip=[::ffff:219.94.190.222] Feb 2 21:14:29 MYSERVER pop3d: LOGIN FAILED, user=alan, ip=[::ffff:219.94.190.222] Feb 2 21:14:35 MYSERVER pop3d: LOGIN FAILED, user=info, ip=[::ffff:219.94.190.222] Feb 2 21:14:41 MYSERVER pop3d: LOGIN FAILED, user=shop, ip=[::ffff:219.94.190.222] Feb 3 06:49:29 MYSERVER postfix/smtpd[25834]: warning: 71.6.142.196: hostname db4142196.aspadmin.net verification failed: Name or service not known Feb 3 06:49:29 MYSERVER postfix/smtpd[25834]: connect from unknown[71.6.142.196] Feb 3 06:49:29 MYSERVER postfix/smtpd[25834]: lost connection after CONNECT from unknown[71.6.142.196] Feb 3 06:49:29 MYSERVER postfix/smtpd[25834]: disconnect from unknown[71.6.142.196] Feb 3 06:52:49 MYSERVER postfix/anvil[25837]: statistics: max connection rate 1/60s for (smtp:71.6.142.196) at Feb 3 06:49:29 Feb 3 06:52:49 MYSERVER postfix/anvil[25837]: statistics: max connection count 1 for (smtp:71.6.142.196) at Feb 3 06:49:29 Feb 3 06:52:49 MYSERVER postfix/anvil[25837]: statistics: max cache size 1 at Feb 3 06:49:29 I have Postfix 2.7.1-1 running on Ubuntu 10.10. This is my (modified por privacy) main.cf: smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu) biff = no append_dot_mydomain = no readme_directory = no smtpd_tls_cert_file = /etc/ssl/certs/smtpd.crt smtpd_tls_key_file = /etc/ssl/private/smtpd.key myhostname = mymailserver.org alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases myorigin = /etc/mailname mydestination = mymailserver.org, MYSERVER, localhost relayhost = mynetworks = 127.0.0.0/8, 192.168.1.0/24 mailbox_size_limit = 0 recipient_delimiter = + inet_interfaces = all inet_protocols = all home_mailbox = Maildir/ smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination mailbox_command = smtpd_sasl_local_domain = smtpd_sasl_auth_enable = yes smtpd_sasl_security_options = noanonymous broken_sasl_auth_clients = yes smtpd_tls_security_level = may smtpd_tls_auth_only = no smtp_tls_note_starttls_offer = yes smtpd_tls_CAfile = /etc/ssl/certs/cacert.pem smtpd_tls_loglevel = 1 smtpd_tls_received_header = yes smtpd_tls_session_cache_timeout = 3600s tls_random_source = dev:/dev/urandom smtp_tls_security_level = may

    Read the article

  • obiee memory usage

    - by user554629
    Heap memory is a frequent customer topic. Here's the quick refresher, oriented towards AIX, but the principles apply to other unix implementations. 1. 32-bit processes have a maximum addressability of 4GB; usable application heap size of 2-3 GB.  On AIX it is controlled by an environment variable: export LDR_CNTRL=....=MAXDATA=0x080000000   # 2GB ( The leading zero is deliberate, not required )   1a. It is  possible to get 3.25GB  heap size for a 32-bit process using @DSA (Discontiguous Segment Allocation)     export LDR_CNTRL=MAXDATA=0xd0000000@DSA  # 3.25 GB 32-bit only        One side-effect of using AIX segments "c" and "d" is that shared libraries will be loaded privately, and not shared.        If you need the additional heap space, this is worth the trade-off.  This option is frequently used for 32-bit java.   1b. 64-bit processes have no need for the @DSA option. 2. 64-bit processes can double the 32-bit heap size to 4GB using: export LDR_CNTRL=....=MAXDATA=0x100000000  # 1 with 8-zeros    2a. But this setting would place the same memory limitations on obiee as a 32-bit process    2b. The major benefit of 64-bit is to break the binds of 32-bit addressing.  At a minimum, use 8GB export LDR_CNTRL=....=MAXDATA=0x200000000  # 2 with 8-zeros    2c.  Many large customers are providing extra safety to their servers by using 16GB: export LDR_CNTRL=....=MAXDATA=0x400000000  # 4 with 8-zeros There is no performance penalty for providing virtual memory allocations larger than required by the application.  - If the server only uses 2GB of space in 64-bit ... specifying 16GB just provides an upper bound cushion.    When an unexpected user query causes a sudden memory surge, the extra memory keeps the server running. 3.  The next benefit to 64-bit is that you can provide huge thread stack sizes for      strange queries that might otherwise crash the server.      nqsserver uses fast recursive algorithms to traverse complicated control structures.    This means lots of thread space to hold the stack frames.    3a. Stack frames mostly contain register values;  64-bit registers are twice as large as 32-bit          At a minimum you should  quadruple the size of the server stack threads in NQSConfig.INI          when migrating from 32- to 64-bit, to prevent a rogue query from crashing the server.           Allocate more than is normally necessary for safety.    3b. There is no penalty for allocating more stack size than you need ...           it is just virtual memory;   no real resources  are consumed until the extra space is needed.    3c. Increasing thread stack sizes may require the process heap size (MAXDATA) to be increased.          Heap space is used for dynamic memory requests, and for thread stacks.          No performance penalty to run with large heap and thread stack sizes.           In a 32-bit world, this safety would require careful planning to avoid exceeding 2GM usable storage.     3d. Increasing the number of threads also may require additional heap storage.          Most thread stack frames on obiee are allocated when the server is started,          and the real memory usage increases as threads run work. Does 2.8GB sound like a lot of memory for an AIX application server? - I guess it is what you are accustomed to seeing from "grandpa's applications". - One of the primary design goals of obiee is to trade memory for services ( db, query caches, etc) - 2.8GB is still well under the 4GB heap size allocated with MAXDATA=0x100000000 - 2.8GB process size is also possible even on 32-bit Windows applications - It is not unusual to receive a sudden request for 30MB of contiguous storage on obiee.- This is not a memory leak;  eventually the nqsserver storage will stabilize, but it may take days to do so. vmstat is the tool of choice to observe memory usage.  On AIX vmstat will show  something that may be  startling to some people ... that available free memory ( the 2nd column ) is always  trending toward zero ... no available free memory.  Some customers have concluded that "nearly zero memory free" means it is time to upgrade the server with more real memory.   After the upgrade, the server again shows very little free memory available. Should you be concerned about this?   Many customers are !!  Here is what is happening: - AIX filesystems are built on a paging model.   If you read/write a  filesystem block it is paged into memory ( no read/write system calls ) - This filesystem "page" has its own "backing store" on disk, the original filesystem block.   When the system needs the real memory page holding the file block, there is no need to "page out".    The page can be stolen immediately, because the original is still on disk in the filesystem. - The filesystem  pages tend to collect ... every filesystem block that was ever seen since    system boot is available in memory.  If another application needs the file block, it is retrieved with no physical I/O. What happens if the system does need the memory ... to satisfy a 30MB heap request by nqsserver, for example? - Since the filesystem blocks have their own backing store ( not on a paging device )   the kernel can just steal any filesystem block ... on a least-recently-used basis   to satisfy a new real memory request for "computation pages". No cause for alarm.   vmstat is accurately displaying whether all filesystem blocks have been touched, and now reside in memory.   Back to nqsserver:  when should you be worried about its memory footprint? Answer:  Almost never.   Stop monitoring it ... stop fussing over it ... stop trying to optimize it. This is a production application, and nqsserver uses the memory it requires to accomplish the job, based on demand. C'mon ... never worry?   I'm from New York ... worry is what we do best. Ok, here is the metric you should be watching, using vmstat: - Are you paging ... there are several columns of vmstat outputbash-2.04$ vmstat 3 3 System configuration: lcpu=4 mem=4096MB kthr    memory              page              faults        cpu    ----- ------------ ------------------------ ------------ -----------  r  b    avm   fre  re  pi  po  fr   sr  cy  in   sy  cs us sy id wa  0  0 208492  2600   0   0   0   0    0   0  13   45  73  0  0 99  0  0  0 208492  2600   0   0   0   0    0   0   9   12  77  0  0 99  0  0  0 208492  2600   0   0   0   0    0   0   9   40  86  0  0 99  0 avm is the "available free memory" indicator that trends toward zerore   is "re-page".  The kernel steals a real memory page for one process;  immediately repages back to original processpi  "page in".   A process memory page previously paged out, now paged back in because the process needs itpo "page out" A process memory block was paged out, because it was needed by some other process Light paging activity ( re, pi, po ) is not a concern for worry.   Processes get started, need some memory, go away. Sustained paging activity  is cause for concern.   obiee users are having a terrible day if these counters are always changing. Hang on ... if nqsserver needs that memory and I reduce MAXDATA to keep the process under control, won't the nqsserver process crash when the memory is needed? Yes it will.   It means that nqsserver is configured to require too much memory and there are  lots of options to reduce the real memory requirement.  - number of threads  - size of query cache  - size of sort But I need nqsserver to keep running. Real memory is over-committed.    Many things can cause this:- running all application processes on a single server    ... DB server, web servers, WebLogic/WebSphere, sawserver, nqsserver, etc.   You could move some of those to another host machine and communicate over the network  The need for real memory doesn't go away, it's just distributed to other host machines. - AIX LPAR is configured with too little memory.     The AIX admin needs to provide more real memory to the LPAR running obiee. - More memory to this LPAR affects other partitions. Then it's time to visit your friendly IBM rep and buy more memory.

    Read the article

  • Understanding Plesk Watchdog statistics

    - by weotch
    We have Plesk 8.3 installed. I've started using their Watchdog module to track server useage. Our server routinely has trouble with the amount of traffic we have and I think our MySQL queries need to be smarter. Anyway, looking at the stats from Watchdog, it seems like MySQL usage is low compared to so something else making up the "overall" usage. See this: I was hoping someone with a lot of Plesk exeprience could help me understand what I'm seeing here. Can I not trust Watchdog's reports or am I missing something?

    Read the article

  • sar command to generate only CPU utilization and network statistics in Linux

    - by Vijay Shankar Kalyanaraman
    I want to be able to generate the system activity report every 30 seconds or every minute and store in a file and use it for diagnostic purposes on my VM. So I give an output file for the sar command and read it using the "-f" option. But I only use the CPU utilization and network utilization part of the report and so rest is all that I don't want to save (waste the space in the disk to store these reports). Also the sar files that are generated are all binary. Is there a way to collect these stats for the CPU and network utilization alone? and so save almost 2/3rds the space on the disk?

    Read the article

  • Performance Monitor (perfmon) showing some unusual statistics

    - by Param
    Recently i have thought to used perfmon.msc to monitor process utilization of remote computer. But i am faced with some peculiar situation. Please see the below Print-screen I have selected three computer -- QDIT049, QDIT199V6 & QNIVN014. Please observer the processor Time % which i have marked in Red Circle. How it can be more than 100%.? The Total Processor Time can never go above 100%, am i right? If i am right? than why the processor time % is showing 200% Please let me know, how it is possible or where i have done mistake. Thanks & Regards, Param

    Read the article

  • need assistance with my.cnf - 1500% CPU usage

    - by Alan Long
    I'm running into a few issues with our new database server. It is a HP G8 with 2 INTEL XEON E5-2650 processors and 32GB of ram. This server is dedicated as a MySQL server (5.1.69) for our intranet portal. I have been having issues with this server staying alive - I notice high CPU usage during certain times of day (8% ~ 1500%+) and see very low memory usage (7 ~ 15%) based on using the 'top' command. When the CPU usage passes 1000%, that is when the app usually dies. I'm trying to see what I'm doing wrong with the config file, hopefully one of the experts can chime in and let me know what they think. See below for my.cnf file: [mysqld] default-storage-engine=InnoDB datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock #user=mysql large-pages # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 max_connections=275 tmp_table_size=1G key_buffer_size=384M key_buffer=384M thread_cache_size=1024 long_query_time=5 low_priority_updates=1 max_heap_table_size=1G myisam_sort_buffer_size=8M concurrent_insert=2 table_cache=1024 sort_buffer_size=8M read_buffer_size=5M read_rnd_buffer_size=6M join_buffer_size=16M table_definition_cache=6k open_files_limit=8k slow_query_log #skip-name-resolve # Innodb Settings innodb_buffer_pool_size=18G innodb_thread_concurrency=0 innodb_log_file_size=1G innodb_log_buffer_size=16M innodb_flush_log_at_trx_commit=2 innodb_lock_wait_timeout=50 innodb_file_per_table #innodb_buffer_pool_instances=4 #eliminating double buffering innodb_flush_method = O_DIRECT flush_time=86400 innodb_additional_mem_pool_size=40M #innodb_io_capacity = 5000 #innodb_read_io_threads = 64 #innodb_write_io_threads = 64 # increase until threads_created doesnt grow anymore thread_cache=1024 query_cache_type=1 query_cache_limit=4M query_cache_size=256M # Try number of CPU's*2 for thread_concurrency thread_concurrency = 0 wait_timeout = 1800 connect_timeout = 10 interactive_timeout = 60 [mysqldump] max_allowed_packet=32M [mysqld_safe] log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid log-slow-queries=/var/log/mysql/slow-queries.log long_query_time = 1 log-queries-not-using-indexes we connect to one database with 75 tables, the largest table has 1,150,000 entries and the second largest has 128,036 entries. I have also verified that our PHP queries are optimized as best as possible. Reference - MySQLtuner: >> MySQLTuner 1.2.0 - Major Hayden <[email protected]> >> Bug reports, feature requests, and downloads at http://mysqltuner.com/ >> Run with '--help' for additional options and output filtering -------- General Statistics -------------------------------------------------- [--] Skipped version check for MySQLTuner script [OK] Currently running supported MySQL version 5.1.69-log [OK] Operating on 64-bit architecture -------- Storage Engine Statistics ------------------------------------------- [--] Status: -Archive -BDB -Federated +InnoDB -ISAM -NDBCluster [--] Data in InnoDB tables: 420M (Tables: 75) [!!] Total fragmented tables: 75 -------- Security Recommendations ------------------------------------------- [!!] User '[email protected]' has no password set. -------- Performance Metrics ------------------------------------------------- [--] Up for: 1h 14m 50s (8M q [1K qps], 705 conn, TX: 6B, RX: 892M) [--] Reads / Writes: 68% / 32% [--] Total buffers: 19.7G global + 35.2M per thread (275 max threads) [!!] Maximum possible memory usage: 29.1G (93% of installed RAM) [OK] Slow queries: 0% (472/8M) [OK] Highest usage of available connections: 66% (183/275) [OK] Key buffer size / total MyISAM indexes: 384.0M/91.0K [OK] Key buffer hit rate: 100.0% (173 cached / 0 reads) [OK] Query cache efficiency: 96.2% (7M cached / 7M selects) [!!] Query cache prunes per day: 553614 [OK] Sorts requiring temporary tables: 0% (3 temp sorts / 1K sorts) [!!] Temporary tables created on disk: 49% (3K on disk / 7K total) [OK] Thread cache hit rate: 74% (183 created / 705 connections) [OK] Table cache hit rate: 97% (231 open / 238 opened) [OK] Open file limit used: 0% (17/8K) [OK] Table locks acquired immediately: 100% (432K immediate / 432K locks) [OK] InnoDB data size / buffer pool: 420.9M/18.0G -------- Recommendations ----------------------------------------------------- General recommendations: Run OPTIMIZE TABLE to defragment tables for better performance MySQL started within last 24 hours - recommendations may be inaccurate Reduce your overall MySQL memory footprint for system stability Increasing the query_cache size over 128M may reduce performance Temporary table size is already large - reduce result set size Reduce your SELECT DISTINCT queries without LIMIT clauses Variables to adjust: *** MySQL's maximum memory usage is dangerously high *** *** Add RAM before increasing MySQL buffer variables *** query_cache_size (> 256M) [see warning above] Thanks in advanced for your help!

    Read the article

  • Setting Key Usage attributes with Makecert

    - by nlawalker
    Is it possible to set Key Usage attributes using makecert, or any other tool I can use to generate my own test certificates? The reason I'm interested is that certificates used for BizTalk Server AS2 transport require a key usage of Digital Signature for signing and Data Encipherment or Key Encipherment for encryption/decryption, and I want to play around with this feature. I see how to set enhanced key usage attributes with makecert, but not key usage.

    Read the article

  • is Boost Library's weighted median broken?

    - by user624188
    I confess that I am no expert in C++. I am looking for a fast way to compute weighted median, which Boost seemed to have. But it seems I am not able to make it work. #include <iostream> #include <boost/accumulators/accumulators.hpp> #include <boost/accumulators/statistics/stats.hpp> #include <boost/accumulators/statistics/median.hpp> #include <boost/accumulators/statistics/weighted_median.hpp> using namespace boost::accumulators; int main() { // Define an accumulator set accumulator_set<double, stats<tag::median > > acc1; accumulator_set<double, stats<tag::median >, float> acc2; // push in some data ... acc1(0.1); acc1(0.2); acc1(0.3); acc1(0.4); acc1(0.5); acc1(0.6); acc2(0.1, weight=0.); acc2(0.2, weight=0.); acc2(0.3, weight=0.); acc2(0.4, weight=1.); acc2(0.5, weight=1.); acc2(0.6, weight=1.); // Display the results ... std::cout << " Median: " << median(acc1) << std::endl; std::cout << "Weighted Median: " << median(acc2) << std::endl; return 0; } produces the following output, which is clearly wrong. Median: 0.3 Weighted Median: 0.3 Am I doing something wrong? Any help will be greatly appreciated. * however, the weighted sum works correctly * @glowcoder: The weighted sum works perfectly fine like this. #include <iostream> #include <boost/accumulators/accumulators.hpp> #include <boost/accumulators/statistics/stats.hpp> #include <boost/accumulators/statistics/sum.hpp> #include <boost/accumulators/statistics/weighted_sum.hpp> using namespace boost::accumulators; int main() { // Define an accumulator set accumulator_set<double, stats<tag::sum > > acc1; accumulator_set<double, stats<tag::sum >, float> acc2; // accumulator_set<double, stats<tag::median >, float> acc2; // push in some data ... acc1(0.1); acc1(0.2); acc1(0.3); acc1(0.4); acc1(0.5); acc1(0.6); acc2(0.1, weight=0.); acc2(0.2, weight=0.); acc2(0.3, weight=0.); acc2(0.4, weight=1.); acc2(0.5, weight=1.); acc2(0.6, weight=1.); // Display the results ... std::cout << " Median: " << sum(acc1) << std::endl; std::cout << "Weighted Median: " << sum(acc2) << std::endl; return 0; } and the result is Sum: 2.1 Weighted Sum: 1.5

    Read the article

  • MongoDB usage best practices

    - by andresv
    The project I'm working on uses MongoDB for some stuff so I'm creating some documents to help developers speedup the learning curve and also avoid mistakes and help them write clean & reliable code. This is my first version of it, so I'm pretty sure I will be adding more stuff to it, so stay tuned! C# Official driver notes The 10gen official MongoDB driver should always be referenced in projects by using NUGET. Do not manually download and reference assemblies in any project. C# driver quickstart guide: http://www.mongodb.org/display/DOCS/CSharp+Driver+Quickstart Reference links C# Language Center: http://www.mongodb.org/display/DOCS/CSharp+Language+Center MongoDB Server Documentation: http://www.mongodb.org/display/DOCS/Home MongoDB Server Downloads: http://www.mongodb.org/downloads MongoDB client drivers download: http://www.mongodb.org/display/DOCS/Drivers MongoDB Community content: http://www.mongodb.org/display/DOCS/CSharp+Community+Projects Tutorials Tutorial MongoDB con ASP.NET MVC - Ejemplo Práctico (Spanish):http://geeks.ms/blogs/gperez/archive/2011/12/02/tutorial-mongodb-con-asp-net-mvc-ejemplo-pr-225-ctico.aspx MongoDB and C#:http://www.codeproject.com/Articles/87757/MongoDB-and-C C# driver LINQ tutorial:http://www.mongodb.org/display/DOCS/CSharp+Driver+LINQ+Tutorial C# driver reference: http://www.mongodb.org/display/DOCS/CSharp+Driver+Tutorial Safe Mode Connection The C# driver supports two connection modes: safe and unsafe. Safe connection mode (only applies to methods that modify data in a database like Inserts, Deletes and Updates. While the current driver defaults to unsafe mode (safeMode == false) it's recommended to always enable safe mode, and force unsafe mode on specific things we know aren't critical. When safe mode is enabled, the driver internal code calls the MongoDB "getLastError" function to ensure the last operation is completed before returning control the the caller. For more information on using safe mode and their implicancies on performance and data reliability see: http://www.mongodb.org/display/DOCS/getLastError+Command If safe mode is not enabled, all data modification calls to the database are executed asynchronously (fire & forget) without waiting for the result of the operation. This mode could be useful for creating / updating non-critical data like performance counters, usage logging and so on. It's important to know that not using safe mode implies that data loss can occur without any notification to the caller. As with any wait operation, enabling safe mode also implies dealing with timeouts. For more information about C# driver safe mode configuration see: http://www.mongodb.org/display/DOCS/CSharp+getLastError+and+SafeMode The safe mode configuration can be specified at different levels: Connection string: mongodb://hostname/?safe=true Database: when obtaining a database instance using the server.GetDatabase(name, safeMode) method Collection: when obtaining a collection instance using the database.GetCollection(name, safeMode) method Operation: for example, when executing the collection.Insert(document, safeMode) method Some useful SafeMode article: http://stackoverflow.com/questions/4604868/mongodb-c-sharp-safemode-official-driver Exception Handling The driver ensures that an exception will be thrown in case of something going wrong, in case of using safe mode (as said above, when not using safe mode no exception will be thrown no matter what the outcome of the operation is). As explained here https://groups.google.com/forum/?fromgroups#!topic/mongodb-user/mS6jIq5FUiM there is no need to check for any returned value from a driver method inserting data. With updates the situation is similar to any other relational database: if an update command doesn't affect any records, the call will suceed anyway (no exception thrown) and you manually have to check for something like "records affected". For MongoDB, an Update operation will return an instance of the "SafeModeResult" class, and you can verify the "DocumentsAffected" property to ensure the intended document was indeed updated. Note: Please remember that an Update method might return a null instance instead of an "SafeModeResult" instance when safe mode is not enabled. Useful Community Articles Comments about how MongoDB works and how that might affect your application: http://ethangunderson.com/blog/two-reasons-to-not-use-mongodb/ FourSquare using MongoDB had serious scalability problems: http://mashable.com/2010/10/07/mongodb-foursquare/ Is MongoDB a replacement for Memcached? http://www.quora.com/Is-MongoDB-a-good-replacement-for-Memcached/answer/Rick-Branson MongoDB Introduction, shell, when not to use, maintenance, upgrade, backups, memory, sharding, etc: http://www.markus-gattol.name/ws/mongodb.html MongoDB Collection level locking support: https://jira.mongodb.org/browse/SERVER-1240 MongoDB performance tips: http://www.quora.com/MongoDB/What-are-some-best-practices-for-optimal-performance-of-MongoDB-particularly-for-queries-that-involve-multiple-documents Lessons learned migrating from SQL Server to MongoDB: http://www.wireclub.com/development/TqnkQwQ8CxUYTVT90/read MongoDB replication performance: http://benshepheard.blogspot.com.ar/2011/01/mongodb-replication-performance.html

    Read the article

  • SQL SERVER – How to Ignore Columnstore Index Usage in Query

    - by pinaldave
    Earlier I wrote about SQL SERVER – Fundamentals of Columnstore Index and very first question I received in email was as following. “We are using SQL Server 2012 CTP3 and so far so good. In our data warehouse solution we have created 1 non-clustered columnstore index on our large fact table. We have very unique situation but your article did not cover it. We are running few queries on our fact table which is working very efficiently but there is one query which earlier was running very fine but after creating this non-clustered columnstore index this query is running very slow. We dropped the columnstore index and suddenly this one query is running fast but other queries which were benefited by this columnstore index it is running slow. Any workaround in this situation?” In summary the question in simple words “How can we ignore using columnstore index in selective queries?” Very interesting question – you can use I can understand there may be the cases when columnstore index is not ideal and needs to be ignored the same. You can use the query hint IGNORE_NONCLUSTERED_COLUMNSTORE_INDEX to ignore the columnstore index. SQL Server Engine will use any other index which is best after ignoring the columnstore index. Here is the quick script to prove the same. We will first create sample database and then create columnstore index on the same. Once columnstore index is created we will write simple query. This query will use columnstore index. We will then show the usage of the query hint. USE AdventureWorks GO -- Create New Table CREATE TABLE [dbo].[MySalesOrderDetail]( [SalesOrderID] [int] NOT NULL, [SalesOrderDetailID] [int] NOT NULL, [CarrierTrackingNumber] [nvarchar](25) NULL, [OrderQty] [smallint] NOT NULL, [ProductID] [int] NOT NULL, [SpecialOfferID] [int] NOT NULL, [UnitPrice] [money] NOT NULL, [UnitPriceDiscount] [money] NOT NULL, [LineTotal] [numeric](38, 6) NOT NULL, [rowguid] [uniqueidentifier] NOT NULL, [ModifiedDate] [datetime] NOT NULL ) ON [PRIMARY] GO -- Create clustered index CREATE CLUSTERED INDEX [CL_MySalesOrderDetail] ON [dbo].[MySalesOrderDetail] ( [SalesOrderDetailID]) GO -- Create Sample Data Table -- WARNING: This Query may run upto 2-10 minutes based on your systems resources INSERT INTO [dbo].[MySalesOrderDetail] SELECT S1.* FROM Sales.SalesOrderDetail S1 GO 100 -- Create ColumnStore Index CREATE NONCLUSTERED COLUMNSTORE INDEX [IX_MySalesOrderDetail_ColumnStore] ON [MySalesOrderDetail] (UnitPrice, OrderQty, ProductID) GO Now we have created columnstore index so if we run following query it will use for sure the same index. -- Select Table with regular Index SELECT ProductID, SUM(UnitPrice) SumUnitPrice, AVG(UnitPrice) AvgUnitPrice, SUM(OrderQty) SumOrderQty, AVG(OrderQty) AvgOrderQty FROM [dbo].[MySalesOrderDetail] GROUP BY ProductID ORDER BY ProductID GO We can specify Query Hint IGNORE_NONCLUSTERED_COLUMNSTORE_INDEX as described in following query and it will not use columnstore index. -- Select Table with regular Index SELECT ProductID, SUM(UnitPrice) SumUnitPrice, AVG(UnitPrice) AvgUnitPrice, SUM(OrderQty) SumOrderQty, AVG(OrderQty) AvgOrderQty FROM [dbo].[MySalesOrderDetail] GROUP BY ProductID ORDER BY ProductID OPTION (IGNORE_NONCLUSTERED_COLUMNSTORE_INDEX) GO Let us clean up the database. -- Cleanup DROP INDEX [IX_MySalesOrderDetail_ColumnStore] ON [dbo].[MySalesOrderDetail] GO TRUNCATE TABLE dbo.MySalesOrderDetail GO DROP TABLE dbo.MySalesOrderDetail GO Again, make sure that you use hint sparingly and understanding the proper implication of the same. Make sure that you test it with and without hint and select the best option after review of your administrator. Here is the question for you – have you started to use SQL Server 2012 for your validation and development (not on production)? It will be interesting to know the answer. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Index, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • Clever memory usage through the years

    - by Ben Emmett
    A friend and I were recently talking about the really clever tricks people have used to get the most out of memory. I thought I’d share my favorites, and would love to hear yours too! Interleaving on drum memory Back in the ye olde days before I’d been born (we’re talking the 50s / 60s here), working memory commonly took the form of rotating magnetic drums. These would spin at a constant speed, and a fixed head would read from memory when the correct part of the drum passed it by, a bit like a primitive platter disk. Because each revolution took a few milliseconds, programmers took to manually arranging information non-sequentially on the drum, timing when an instruction or memory address would need to be accessed, then spacing information accordingly around the edge of the drum, thus reducing the access delay. Similar techniques were still used on hard disks and floppy disks into the 90s, but have become irrelevant with modern disk technologies. The Hashlife algorithm Conway’s Game of Life has attracted numerous implementations over the years, but Bill Gosper’s Hashlife algorithm is particularly impressive. Taking advantage of the repetitive nature of many cellular automata, it uses a quadtree structure to store the hashes of pieces of the overall grid. Over time there are fewer and fewer new structures which need to be evaluated, so it starts to run faster with larger grids, drastically outperforming other algorithms both in terms of speed and the size of grid which can be simulated. The actual amount of memory used is huge, but it’s used in a clever way, so makes the list . Elite’s procedural generation Ok, so this isn’t exactly a memory optimization – more a storage optimization – but it gets an honorable mention anyway. When writing Elite, David Braben and Ian Bell wanted to build a rich world which gamers could explore, but their 22K memory was something of a limitation (for comparison that’s about the size of my avatar picture at the top of this page). They procedurally generated all the characteristics of the 2048 planets in their virtual universe, including the names, which were stitched together using a lookup table of parts of names. In fact the original plans were for 2^52 planets, but it was decided that that was probably too many. Oh, and they did that all in assembly language. Other games of the time used similar techniques too – The Sentinel’s landscape generation algorithm being another example. Modern Garbage Collectors Garbage collection in managed languages like Java and .NET ensures that most of the time, developers stop needing to care about how they use and clean up memory as the garbage collector handles it automatically. Achieving this without killing performance is a near-miraculous feet of software engineering. Much like when learning chemistry, you find that every time you think you understand how the garbage collector works, it turns out to be a mere simplification; that there are yet more complexities and heuristics to help it run efficiently. Of course introducing memory problems is still possible (and there are tools like our memory profiler to help if that happens to you) but they’re much, much rarer. A cautionary note In the examples above, there were good and well understood reasons for the optimizations, but cunningly optimized code has usually had to trade away readability and maintainability to achieve its gains. Trying to optimize memory usage without being pretty confident that there’s actually a problem is doing it wrong. So what have I missed? Tell me about the ingenious (or stupid) tricks you’ve seen people use. Ben

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 13 14 15 16 17 18 19 20 21 22 23 24  | Next Page >