Performance tuning is the process of modifying a system to improve its efficiency. This is also known as optimizing.
3
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2answers
367 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
votes
2answers
189 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 ...
1
vote
2answers
300 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
506 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 ...
0
votes
2answers
98 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 ...
4
votes
1answer
504 views
How do I test the effect of ionice (against a device using the cfq scheduler)?
I'm trying to construct an experiment to measure the effect of ionice. What I'd like to do is to (per another answer on serverfault) cause frequent enough I/O that a sufficiently "niced" process is ...
4
votes
1answer
492 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:
...
2
votes
1answer
629 views
InnoDB options crashing mysql start AND mysql tuning
I have an innodb on a Ubuntu 10.10 server running on an ESXi platform. I have dedicated 8 CPUs, 32 Gigs of ram, and files stored in a Raid 5 HP SAN of SAS 10k rpm disks. I'm expecting FAST queries! ...
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1answer
331 views
Manage Win7 Performance Options via GPO
Our company has many virtual Windows 7 instances. Based on recommendations from VMWare, we want to customize the visual effects to optimize performance. We have found that we can change the following ...
1
vote
1answer
328 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.
...
1
vote
1answer
837 views
NGinx vs Varnish as a reverse proxy in front of Apache w/php
I am using apache with mod_php to serve content. Mostly the content is fetched form memcache over the network. All of my images, css and js are already on a cdn
What are the pros and cons of putting ...
1
vote
1answer
605 views
How to check for bottlenecks in Windows Server 2008 R2
I recently switched out a 10 year old server for a brand new server in a small office and upgraded from Windows Server 2000 to Windows Server 2008 R2. After the switch was complete and some ...
1
vote
1answer
441 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 ...
0
votes
1answer
47 views
How do I increase UDP Recv-Q
I have a gigabit connection that is not fully utilized but I am getting packet receiving loss.
When I do netstat, it shows the Recv-Q sometimes maxes out at 262656 during heavy traffic.
Proto Recv-Q
...
0
votes
1answer
59 views
Too much I/O generated by postgres stats collector process
I am using XenServer with several virtual machines having local postgres databases. Even when all applications are unused and the databases are idle, each vm causes constant storage network traffic ...
0
votes
1answer
73 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 ...
0
votes
1answer
207 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 ...
0
votes
1answer
430 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, ...
0
votes
1answer
541 views
MySQL Memory usage
Our MySQL server seems to be using a lot of memory.
I've tried looking for slow queries and queries with no index and have halved the peak CPU usage and Apache memory usage but the MySQL memory stays ...
0
votes
1answer
185 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 ...
0
votes
1answer
233 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 ...
0
votes
1answer
138 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 ...
0
votes
1answer
812 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 ...
-1
votes
1answer
217 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 ...
-3
votes
1answer
117 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
159 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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0answers
51 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
136 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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0answers
388 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 ...
0
votes
0answers
17 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 ...
0
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0answers
28 views
Distributed Ehcache Performance vs StandAlone
i am fairly new to Terracotta and EhCache.
I am actaully using the Bigmemory Max version (EhCache 2.7.0 ang TSA 4.0.0) to my project.
I managed to successfully deploy a Terracotta Cluster with two ...
0
votes
0answers
55 views
Varnish: Exclude section of page
Is there any way to exclude some webpage parts from cache? For example, I have Recent Additions block on my homepage which gets refreshed after every 15mins.
I know there is something like ESI ...
0
votes
0answers
100 views
How to start digging into my Apache + PHP-FPM performance issues
I've found lots of discussion here and elsewhere about the tradeoffs between Apache vs. Nginx, worker vs. prefork, mod_php vs. FastCGI + PHP-FPM, etc., but I'm finding it difficult to determine how I ...
0
votes
0answers
142 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 ...
0
votes
0answers
144 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 - ...
0
votes
0answers
32 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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0answers
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 ...
0
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0answers
397 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 ...
0
votes
0answers
451 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 ...
0
votes
0answers
161 views
SQL server peformance, virtual memory usage
I have a very large DB used mostly for analytics. The performance overall is very sluggish. I just noticed that when running the query below, the amount of virtual memory used greatly exceeds the ...
