Questions tagged [performance-tuning]
Performance tuning is the process of modifying a system to improve its efficiency. This is also known as optimizing.
413
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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 ...
3
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2
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How do I disable "Processor Power and Utilization Monitoring" on an HP ProLiant server?
I'm tuning my server for low-latency. The HP low-latency guide suggests to disable this option "Processor Power and Utilization Monitoring" because:
Disables iLO Processor State Mode Switching
and ...
0
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1
answer
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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
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1
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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 ...
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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
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1
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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: ...
11
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3
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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 ...
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1
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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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2
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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
...
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0
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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 ...
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2
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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 ...
3
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2
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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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1
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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
1
answer
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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 ...
4
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3
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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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2
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765
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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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1
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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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3
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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 ...
6
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1
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13k
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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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1
answer
992
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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 ...
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6
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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 3....
6
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1
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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 ubuntu-12....
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1
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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 ...
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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 ...
2
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0
answers
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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
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1
answer
264
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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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1
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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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1
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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:
http://www.experts-exchange.com/OS/Linux/...
12
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3
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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.
...
5
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2
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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 27 ...
0
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1
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MySQL Threads or what is this
How can I reduce that number? I have a quad core machine. Do I need to edit thread_pool_size and by reducing them do I get better performance?
Should a lot of queries or something happen could is ...
2
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2
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Troubleshooting poor disk IO performance
Note that while this question is a little Redis-specific, the main problem is generic: a process takes so much HDD IO write bandwidth that other processes can't write anything.
We've got an Ubuntu VM ...
0
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1
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503 error Varnish cache when eAccelerator is started
I have a Magento installation running on x-large Amazon server. I have Varnish, memcached and eAccelerator installed on the server. At first everything was working fine, but then at some point it ...
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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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1
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JVM tuning in JBOSS AS 7
Can anyone explain as to where and how do I configure the following JVM parameters to tune JBOSS. I am using the latest JBOSS AS 7.
I am using openJDK-6 on Linux.
The following are the parameters ...
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1
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RRAS (Routing and Remote Access) change process priority to "realtime"?
I have a windows server 2012 running RRAS and some other services.
Beacause of that I guess I have experience some slowdowns and dropout of package.
My question is how to find, and change the ...
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1
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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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1
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Doubled up RAM to 32 GB - now how to speed up a "LAPP" server?
I run a small Facebook game at a CentOS 6.3 quad core machine with PostgreSQL 8.4.3 + few PHP scripts (doing mostly select queries) + 1 Perl daemon and even though the server worked ok, I've suggested ...
3
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3
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HP P410 RAID + Samsung 830 SSDs + Debian 6.0 - What performance to expect?
I'm renting two dedicated servers from a hosting company. Here are the specs:
server1:
HP ProLiant DL165 G7
2x AMD Opteron 6164 HE 12-Core
40 GB RAM
HP Smart Array P410 RAID controller
2x Samsung 830 ...
5
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1
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4k
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Openfiler iSCSI performance
Hoping someone can point me in the right direction with some iSCSI performance issues I'm having. I'm running Openfiler 2.99 on an older ProLiant DL360 G5. Dual Xeon processor, 6GB ECC RAM, Intel ...
2
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1
answer
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Server hanging when serving random file on page load
I'm optimising a website, and the problem I'm facing with now is server related. During page load, there are about 40-50 requests sent to server (depending on the page), and in every case, server ...
2
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1
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Different block sizes for partition and underlying logical disk on HP Raid Controller (Linux)
Following links collected in this thread I started to check blockdev and found the following output indicating different sizes for partition c0d9p1 and the underlying device (c0d9):
[root@machine ~]# ...
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0
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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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1
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Perfmon - Redirector current command 0 result
I'd like to monitor how many SMB connections there are at any given time for my 2008R2 file server, but when I add Redirector/Current Commands in perfmon, I get 0 results.
This KB from Microsoft isn't ...
6
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1
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How to prevent IO Load under Linux for Video serving?
I'm currently serving videos of conferences via Nginx on 3 servers; 4 cores, enough memory (no swap used) and RAID-10 with 8 drives per server. Unfortunately iostat -xd 1 gives me 100% on all 3 ...
9
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4
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How to achieve 500K requests per second on my webserver? [closed]
I recently gifted myself a new dedicated server and I am trying to squeeze maximum performance out of it, for fun and learning.
I am trying to achieve maximum possible requests per second this server ...
18
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9
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Apache Tomcat chokes after 300 connections
We have an apache webserver in front of Tomcat hosted on EC2, instance type is extra large with 34GB memory.
Our application deals with lot of external webservices and we have a very lousy external ...
0
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1
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Linux kernel 3 TCP IP tuning
I found several resources about tuning linux TCP/IP stack parameters in /etc/sysctl.conf for high bandwidth connections, but all refer to kernel 2.6.
Does anyone have suggestions about how to tune ...
0
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4
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Exchange 2010 SP2 OWA performance
How do I increase performance in OWA 2010 SP2?
I am running CAS on a seperate installation, which has 8GB RAM and 4 CPU cores - running virtualized in a vmware environment.
However, the load times ...
0
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2
answers
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How can I decide up the nature of performed IO?
I am using Linux (3.2.12-3.2.4).
I have few "syncer" processes which updates lots and lots SQLite db files in a loop. The database sizes vary from 1 MB to few GB.
I have a "searcher" process which ...