Performance tuning is the process of modifying a system to improve its efficiency. This is also known as optimizing.

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422 views

IIS 7 — how to track down mysterious network & cpu usage?

I've got a 64-bit Server 2008 (R1) box running IIS. Users were complaining about extremely slow-loading pages. After digging around I found: After isolating the box so only one user was able to ...
2
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2answers
601 views

Changing memory allocator to Jemalloc Centos 6

After reading this blog post about the impact of memory allocators like jemalloc on highly threaded applications, I wanted to test things on a larger scale on some of our cluster of servers. We run ...
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2answers
398 views

Solaris: Increase TCP's Initial Congestion Window to 10 segments (tcp slow-start)

How can the Initial Congestion Window be increased to 10? It seems it can be done with TCP_INIT_CWND, but I don't know how to do that.
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2answers
571 views

Diagnosing poor performance on IIS / ASP.NET / MSSQL app

I'm trying to diagnose the cause of poor performance from a third-party web application we've deployed; the environment is: ASP.NET on IIS, Windows 2003 Server SQL Server 2008 on a separate Windows ...
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2answers
100 views

what to check for limitations if a linux machine maxes out at a certain connection/s

I have a linux machine with a dummy HTTP server on it. It accepts a certain number of connections/second. Neither the CPU (it is a multicore) nor the memory nor IO are exhausted. What else can be ...
3
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1answer
606 views

How to remove the pause during JBoss 5.1.0 GA boot between ProfileServiceBootstrap and AnnotationCreator?

I've managed to strip down my JBoss profile enough that it boots in 1.5 minutes. I started with the web profile and started pulling out stuff I didn't need. The bulk of my boot time can be seen here: ...
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1answer
133 views

KVM Slow performance on XP Guest

The system is very slow to do anything, even browse a local folder, and CPU sits at 100% frequently. Guest is XP 32 bit. Host is Scientific Linux 6.2, Libvirt 0.10, Guest XP OS shows ACPI ...
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1answer
482 views

How do change the max IO request size on Windows Server 2008 R2

As I understand it Windows Server 2008 R2 has the ability to send IO requests to the storage subsystem of up to 1MB in size. Back in the Server 2003 era (and before) this used to be limited to 64KB. ...
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1answer
465 views

Why is MySQL table_cache full but never used

I have been using the tuning-primer.sh script to tune my my.cnf settings. I have most things working well but the part about TABLE CACHE makes no sense: TABLE CACHE Current table_cache value = 900 ...
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1answer
38 views

how to disable all caches types in mysql server in order to do performance testing for my queries

I'm using Mysql Server 5.6.15 and i have a huge database with many complex queries. it seems that when I run the query the first time it takes X amount of time. when I execute it again it takes ...
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1answer
55 views

PHP Settings [pm.max_children, pm.start_servers, pm.min_spare_servers and pm.max_spare_servers]

In the midst of transferring a website from a GoDaddy shared server to an EC2 instance. Handling the traffic, which during peak times on a typical day is around 300 active visitors, has been ...
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1answer
88 views

performance monitor in iis 7 to monitor which website is using most resources (asp.net)

I am using Windows Server 2008 R2 and IIS 7.5, and am hosting multiple websites on the same webserver. Is it possible to use Performance Monitor to know on average which website is using the most ...
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1answer
171 views

Why am I getting a Sudden Drop in throughput and sluggishness with no CPU increase

Occasionally, during random parts of the day, I get a 10 minute period of extreme sluggishness where my requests are taking 50-1000 times longer then they normally do. Note: I am on Apache/2.2.16 ...
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1answer
233 views

Windows 2003 IIS webserver (testserver) is slow

I have a test environment for my Asp.Net 4.0 web applications. It runs on a Dedicated Windows 2003 Webserver (IIS 6) But it's slow! The machine never has 100% cpu and the same for memory. When I run ...
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1answer
511 views

Improving TCP performance over a network with small packet loss

I’m trying to improve my TCP throughput over a “high delay network”, with some packet drops, between Linux machines. I set tcp_mem, tcp_wmem and tcp_rmem to “8192 20530752 20530752”. I set rmem_max, ...
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1answer
237 views

ionice or chrt for Bonnie benchmark

I am running Bonnie benchmark on an embedded device and I am getting variable results for every run. I am contemplating using ionice and / or chrt to get around it. Can you suggest which option is ...
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1answer
269 views

IIS 7.0 - responses throttled to 500ms blocks?

Scenario: ASP.NET MVC wep app sitting on my local machine (Vista Ultimate, IIS 7.0), nothing going on except one user (me) logged in and viewing an index page. The page includes 9 dynamic images drawn ...
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1answer
144 views

Need help tuning Mysql and linux server

We have multi-user application (like MailChimp,Constant Contact) . Each of our customers has it's own contact's list (from 5 to 100.000 contacts). Everything is stored in one BIG database (currently ...
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1answer
890 views

apache and ajp performance

I have an apache sitting in front of two tomcat app servers(one on the same physical server, the other on a different one) that does time consuming work(0.5 sec to 10sec per request). The apache http ...
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1answer
418 views

MySQL runs at >=100% CPU, heavy disk I/O?

Recently my Debian Linux server has been experiencing slow web server response times. I've investigated and it seems that MySQL is the culprit, yet there are no slow queries indicated by the slow ...
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1answer
147 views

Can a large number of network hardware interrupts cause a machine to be underutilized?

I don't know much about networking sorry. I'm building a client / server where the server streams a lot of data to the client and I'm trying to maximise throughput (through TCP). If I run both client ...
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0answers
225 views

Copying cause big iowait

I have dedicated server with 3 HDD. System disk, backup disk (same as system disk) and data disk. When I copy lot of data with cp (say, between backup disk and data disk) load average goes sky high. ...
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77 views

Getting the virtual memory address for (major) page faults

On a Linux (Cent OS 5) system, I have a process that accesses a large amount of memory mapped files. The process is generating a large amount of page faults because the aggregated size of the mapped ...
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0answers
184 views

Can I tune my Debian KVM server to benefit my Windows guest?

Debian Squeeze KVM server with Win2k8 server guest. The server has 16GBs of RAM and the guest only runs MS SQL, with a 15GB database on it. I am wondering if there is anything I can tune from the ...
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424 views

server benchmarking with apache benchmark

We are testing one of our production server with ab and what we found is apr_socket_recv: Connection timed out (110) Total of 176 requests completed after some time above output.That means the ...
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0answers
33 views

Lots of packets pruned from receive queue because of socket buffer overrun - reason to worry?

I know this question has been asked before, but maybe not in this particular context: I have a setup with a couple of MS2008R2 HyperVisor servers running a number of Ubuntu guests. Our webproxy runs ...
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0answers
27 views

famd/gamin timeout issue with courier-imap

I'm running a mail server for about 200 users with courier-imap on Debian 7. This server is running a linux kernel 2.6.38 inside a Xen guest having 2 cpu cores and 2 GB RAM. The server accept ...
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0answers
69 views

What's the bottle neck of server hit 100K request?

The following are two graph of my digital ocean vps instance handle load test request. 10K/s, The only different is the request file size, first is 10K, the second is 20K. Can any one point out the ...
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0answers
59 views

tuning apache for low ram low traffic server

I have a low end VPS server with 512megs of ram to host downloads of files (~10-25megs each). what is a good configuration for the following parameters in apache. I expect no more than 10 human users ...
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0answers
40 views

OpenSSL performance oddity

I've seen something odd regarding OpenSSL performance. This is the output of 'openssl speed aes-128-cbc' on a physical HP Bl460c Gen8 with dual E5-2680's running RHEL/OEL 6.4x64 and OpenSSL ...
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0answers
29 views

Ubuntu backup script kills performance

I run a nightly backup, which takes about 1 hour. During that the performance is bad as hell. It looks pretty much like this: # DB dump ionice -c 3 nice -n 20 mysqldump --skip-lock-tables --user=foo ...
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22 views

SQL Server : Improve SIMPLE SELECT to retun 2 LAC Rows faster?

We have a stored procedure in which we are creating a temp table which has more than 200,000 rows with 30 columns (2 of DATETIME, 4 of INT, 5 of [numeric](20, 3) and rest of VARCHAR(500) data types. ...
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0answers
153 views

How to avoid Memory “Hard Fault/sec”

i've a problem on my windows 2008 server x64, and i cannot understand how can i solve it. i'm looking to Resource Monitor and see about 100 to 200 hard faults/sec. and generally the machine is slow. ...
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0answers
101 views

Mysql Server Performance Hit from Triggers

I have 50 databases on a reasonably spec'd Debian MySQL Server v5.1.63 The size of these database vary from about 3MB -> 7GB each. Each database has a history database and most( but not all) tables ...
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0answers
175 views

RAID10 (4x SSD) system is super slow for 'dd' and 'find' commands

I have configured two servers each with 32 GByte RAM, 2x Xeon 2.4 GHz, 4x 480 GByte Intel SSD on a LSI MegaRAID SAS 9261-8i controller. They should be identical, however one of them has a very poor ...
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370 views

Ubuntu 12.04 64bit - What would cause high System CPU %sys during high MySQL loads?

128GB RAM, 32cores Xeon RAID 10 SSD. Mysql version is the latest 5.5 for Ubuntu 12.04 . We have a lot of queries - about 1800+ per second. During high MySQL load - 2700+% load on a 32 CPU system - ...
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0answers
37 views

Job run-time variations on dual socket computer

I'm running scientific software (WRF-NMM, atmosphere simulation, weather prediction). On all computers I used it, job running times of run cycles were consistent. All those machines were one socket, ...
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39 views

issues with IEEE authentication

We have an application managing other systems in the network solving thier issues.After some days it became un-responsive (applications became unresponsive and windows freezes) I have confirmed ...
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0answers
490 views

Cannot enlarge MySQL Innodb_Buffer_Size, causes MySQL to crash

I currently have innodb_buffer_size set to 2GB - yet I have well over 5GB of innodb databases, and another 4 gigs of free ram on the server (Centos 5). I tried to increase the value to 3 gig, but ...
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501 views

Nginx Slower than Apache?

I've just setup 2x identical Rackspace Cloud instances and am doing some comparisons and benchmarks to compare Apache and Nginx. I'm testing with a 3.4k png file and initially 512MB server instances ...