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

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348 views

How to identify which MySQL queries take a lot of time?

My MySQL server is consuming a lot of memory. Memory footprint 1. Memory consumption in descending order (top 4) MySQL's memory consumption in particular - Why is there so many number of mysqld ...
0
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1answer
377 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 ...
1
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1answer
266 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 ...
2
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1answer
8k views

Improving OpenVPN Performance

I've been trying to improve my OpenVPN performance and this is my current setup: cat /etc/openvpn/server.conf port 443 #- port proto tcp #- protocol dev tun #tun-mtu 1500 tun-mtu-extra 32 #mssfix ...
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2answers
42 views

How to exclude requests from unwanted sources

Scenario: Client buys our analytics services and includes our analytics SDK in his mobile app. Users who download the app will start sending us lots of data. When the client stops paying for our ...
5
votes
2answers
136 views

ZFS Equivalent of lvdisplay snap_percent

I've been using LVM snapshots for backing up MySQL databases. FLUSH TABLES WITH READ LOCK is issued and then lvcreate --snapshot --size 4G etc. Because the database is live while the snapshot is ...
0
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1answer
241 views

PCIe SSD vs SSD vs SAS - which is best for Database?

Since I am going on shipping soon I wonder which generally will mostly boost the database performance ? The bridge question is - which will boost mostly a database which having a lot of random block ...
0
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2answers
185 views

Centos 6.4 Installed in System X3750 M4 IBM Server [duplicate]

We have installed Centos 6.4 in System X3750 M4 IBM Server. But the server is not showing the performance of at-least a normal Desktop Configuration. We haven't done any performance tuning in the ...
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1answer
131 views

MySQL settings for MAXIMUM performance / can be specific to particular DB or user? [closed]

We have a dedicated server, a very powerful one, and I don't believe we are getting the most out of MySQL. Even when running ultra-heavy processes that take a very long time to complete, I'm showing ...
0
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1answer
24 views

One Slower/Larger VS Two Faster/Smaller RAM [closed]

Generally speaking, performance-wise, which one is the best (putting brands aside)? 1x 8GB 1333MHz RAM or 2x 4GB 2400MHz RAM Both DDR3.
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votes
1answer
173 views

Server optimization for long running script [duplicate]

I have a system running on a remote VPS whose main feature is a long running script (it could run for about 10 hours, depending on the user input). The following are some of its features: Database ...
0
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0answers
558 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. ...
4
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3answers
4k views

Understanding RedHat's recommended tuned profiles

We are going to roll out tuned (and numad) on ~1000 servers, the majority of them being VMware servers either on NetApp or 3Par storage. According to RedHats documentation we should choose the ...
0
votes
2answers
2k views

LAMP -> CPU usage of Apache processes too high

I have a LAMP system with CentOS 6.4, Apache 2.2.15, MySQL 5.5.32 and PHP 5.3.26 with APC 3.1.10 using a Drupal CMS (https) on a virtual machine with 4 CPUs and 6 GB RAM. My problem is the CPU usage ...
0
votes
1answer
154 views

How do I go about finding the bottleneck in a slow web based chat application

I am working on a one-to-one chat application running in production. It uses StropheJS to connect to Ejabberd server over BOSH (using ejabberd's default connection manager). The main problem we are ...
-1
votes
1answer
88 views

IIS - Overuse of memory is normal? [closed]

I have two servers running Asp.net applications. Sometimes applications are too slow and memory usage seems exaggerated. Specifications: SERVER #1 OS: Microsoft Windows 2003 R2 Memory: 4GB ...
-2
votes
1answer
435 views

HP DL360p Gen8 for low latency trading - what to upgrade? [closed]

I'm using HP DL360p Gen8 for low latency trading (but not ultra-low-latency!). It means that i'm working in frame about "10+ microseconds" and i don't care about "1-5 microsecond" or nanoseconds. I ...
2
votes
1answer
2k views

How do I disable “Processor Power and Utilization Monitoring” on an HP ProLiant server?

I'm tuning my server for low-latency The guide suggests to disable this option "Processor Power and Utilization Monitoring" because: Disables iLO Processor State Mode Switching and Insight Power ...
1
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1answer
228 views

TCP RWIN, MSS and MTU [closed]

I have been doing some reading into TCP Receive Window (RWIN), Maximum Segment Size (MSS) and Maximum Transmission Unit (MTU). Right off the bat I have some questions and I need a power user's help! ...
0
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1answer
157 views

epoll timeout configuration in lighttpd

Is there a configuration option to tune epoll timeout in lighttpd? I'm developing an embedded Linux (2.6) device, with lighttpd 1.4.30. And I'm observing the following issue: even when the system is ...
0
votes
1answer
33 views

Before buying it, how can I tell if a storage array makes certain performance counters available over SNMP?

I've noticed that documentation for SNMP reporting that is built-in to devices (i.e. doesn't need an agent running in an OS) usually doesn't include a list of performance counters that are available ...
1
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1answer
3k 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 ...
2
votes
1answer
329 views

Apache high CPU usage, setting a overload limit

On a ubuntu server, I run a LAMP environment with APC, and fast-cgi as php mod, to host 2 wordpress sites, and both sites have Wordpress Total Cache (W3TC) plugin configured. The server's specs are: ...
4
votes
2answers
1k 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
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1answer
330 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
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2answers
769 views

virtual memory optimization on exchange server 2010

Hi I did some Google searching but came up blank I know mycomputer/computer > Properties > advance System settings > Advance[tab] > Settings[Performance] > Advance [Tab] > Change > customsige ...
3
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0answers
260 views

TCP tunning for ssh port forwarding [closed]

I am using an ubuntu openssh server to allow users to connect to and do dynamic port forwarding. the performance is good until about 100 users are connected. beyond that the performance is dropped too ...
10
votes
2answers
8k views

Should we mount with data=writeback and barrier=0 on ext3?

We've been running a server on a VM at a hosting company, and have just signed up for a dedicated host (AMD Opteron 3250, 4 cores, 8GB RAM, 2 x 1TB in software RAID, ext3). While running performance ...
2
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2answers
2k 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 ...
0
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1answer
472 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 ...
2
votes
1answer
4k views

Apache HTTPD configuration for high load [duplicate]

Good day, I want to be able to serve at least 7000 (preferably 10k) concurrent requests from my Apache Httpd. I have configured my httpd.conf with MPM worker with the following setup ServerLimit ...
2
votes
1answer
6k 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 ...
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2answers
203 views

Visualize overloaded nic in linux (kernel time)?

I have a linux server that keeps getting its NIC overloaded and I need to visualize how and why this is occurring based on connections and CPU utilization. How do I do this? For example; for me to ...
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0answers
306 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
192 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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0answers
570 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
47 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, ...
3
votes
3answers
749 views

Disk write speed much slower than read speed

I have a VPS server (WiredTree), running CentOS. After experiencing some performance issues I created a simple benchmark for disk read/write speed using the following script: echo Write to disk dd ...
3
votes
1answer
2k views

Strange high CPU I/O wait on postgresql server

I'm really struggling with a performance issue currently, where all my database queries takes up to a 1000 times more than normally, when my database server is under "heavy" load. I have a server ...
0
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1answer
366 views

High response time with pingdom

I have a server hosted at my end, I am monitoring the server with pingdom and also my router. Strange thing is the response time towards the router is fine, but when the traffic flows towards the ...
1
vote
6answers
2k views

How to know if my nginx is in good health?

I am running a nginx on EC2 (m1.small) for SSL termination. I am using 2 workers on Ubuntu, with latest nginx (stable), the network throughput is around 2Mbps and system load average is around 2 to ...
1
vote
1answer
3k views

Lot of FIN_WAIT2, CLOSE_WAIT , LAST_ACK and TIME_WAIT in Haproxy

We are running haproxy in production for around 10k+ concurrent users. But we are seeing lot of FIN_WAIT2, CLOSE_WAIT , LAST_ACK and TIME_WAIT in the netstat output. This output is on a 8G ...
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votes
1answer
255 views

Which will give more free RAM to linux? [closed]

Trying to avoid some issues so I've been trying to learn vm. in kernel tuning but still a little confused even after googling. The lower background_ratio is the sooner the flushes? the lower ...
1
vote
1answer
521 views

VM Tuning to enhance performance

vm.bdflush = 100 1200 128 512 15 5000 500 1884 2 vm.dirty_ratio = 20 vm.dirty_background_ratio = 10 vm.swappiness = 10 vm.min_free_kbytes = 300000 That means that the MOST dirty data that can be in ...
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0answers
89 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 ...
0
votes
1answer
167 views

Adding varnish and memcached to an running single server web site

Current set up; I have a single dedicated server running a web site (it's a lamp stack forum) OS : CentOS CPU : Dual 3.2Ghz Quad-core Xeons RAM : 40GBs (10x4GB DIMMs) Storage : Software RAID1 with ...
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1answer
262 views

CFQ vs Deadline - performance benefits [closed]

Running CPanel and wondering what would be the best for web hosting? deadline is more balanced over CFQ right so would allow for more I/O activities right
3
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1answer
3k views

Disabling CPU management

If I add the following processor.max_cstate=0 to the kernel command line for boot up, does that disable all CPU power management and throttling? I also found: ...
7
votes
2answers
3k views

CPU0 is swamped with eth1 interrupts

I've got an Ubuntu VM, running inside Ubuntu-based Xen XCP. It hosts a custom FCGI-based HTTP service, behind nginx. Under load from ab the first CPU core is saturated, and the rest is under-loaded. ...
3
votes
2answers
338 views

Uneven CPU core utilization

tl;dr: First CPU core is consistently saturated, all other cores are consistently under-loaded. A VM, inside Ubuntu-based Xen XCP: $ uname -a Linux MYHOST 2.6.38-15-virtual #59-Ubuntu SMP Fri Apr ...