Difference between revisions of "TCP-Tuning"

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= Performance TCP =
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= TCP Performance =
  
Cette page décrit les paramètres du kernel Linux qui sont importants pour améliorer la performance réseaux.
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This page describes how to enhance the performance of data transfers. It mainly focus on the optimization of the Linux kernel parameters.
  
== Les paramètres importants ==
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== Kernel parameters ==
Les paramètres suivants sont importants :
 
* net.ipv4.tcp_rmem
 
* net.ipv4.tcp_wmem
 
* net.ipv4.tcp_mem
 
* net.core.rmem_default
 
* net.core.wmem_default
 
* net.core.rmem_max
 
* net.core.wmem_max
 
* net.ipv4.tcp_dsack
 
* net.ipv4.tcp_sack
 
* net.ipv4.tcp_timestamps
 
* net.core.netdev_max_backlog
 
  
Ces paramètres sont modifiés :
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The following are important for TCP tuning:
* par Quattor
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* <code>net.ipv4.tcp_rmem</code>
* par YAIM
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* <code>net.ipv4.tcp_wmem</code>
* en modifiant manuellement le fichier /etc/sysctl.conf
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* <code>net.core.rmem_default</code>
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* <code>net.core.wmem_default</code>
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* <code>net.core.rmem_max</code>
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* <code>net.core.wmem_max</code>
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* <code>net.ipv4.tcp_dsack</code>
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* <code>net.ipv4.tcp_sack</code>
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* <code>net.ipv4.tcp_timestamps</code>
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* <code>net.core.netdev_max_backlog</code>
  
 +
They can be modified with:
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* Quattor ;
 +
* YAIM ;
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* Manually by modifying the <code>/etc/sysctl.conf</code> file.
  
== Valeurs proposées ==
 
  
net.ipv4.tcp_rmem = 131072      1048576 2097152
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== Recommended values ==
net.ipv4.tcp_wmem = 131072      1048576 2097152
 
net.ipv4.tcp_mem = 10%mem      25%mem  50%mem
 
net.core.rmem_default = 1048576
 
net.core.wmem_default = 1048576
 
net.core.rmem_max = 2097152
 
net.core.wmem_max = 2097152
 
net.ipv4.tcp_dsack = 0
 
net.ipv4.tcp_sack = 0
 
net.ipv4.tcp_timestamps = 0
 
net.core.netdev_max_backlog = 10000
 
  
 +
* <code>net.ipv4.tcp_rmem = 131072 1048576 2097152</code>
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* <code>net.ipv4.tcp_wmem = 131072 1048576 2097152</code>
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* <code>net.core.rmem_default = 1048576</code>
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* <code>net.core.wmem_default = 1048576</code>
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* <code>net.core.rmem_max = 2097152</code>
 +
* <code>net.core.wmem_max = 2097152</code>
 +
* <code>net.ipv4.tcp_dsack = 0</code>
 +
* <code>net.ipv4.tcp_sack = 0</code>
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* <code>net.ipv4.tcp_timestamps = 0</code>
 +
* <code>net.core.netdev_max_backlog = 10000</code>
  
== Liens externes ==
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 +
== External links ==
 +
* http://fasterdata.es.net/
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* http://monalisa.cern.ch/FDT/documentation_syssettings.html
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* http://indico.cern.ch/contributionDisplay.py?sessionId=31&amp;contribId=55&amp;confId=61917
 +
* http://www.psc.edu/networking/projects/tcptune/
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* http://onlamp.com/pub/a/onlamp/2005/11/17/tcp_tuning.html
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* http://en.wikipedia.org/wiki/TCP_tuning

Version du 14:20, 8 avril 2010

TCP Performance

This page describes how to enhance the performance of data transfers. It mainly focus on the optimization of the Linux kernel parameters.

Kernel parameters

The following are important for TCP tuning:

  • net.ipv4.tcp_rmem
  • net.ipv4.tcp_wmem
  • net.core.rmem_default
  • net.core.wmem_default
  • net.core.rmem_max
  • net.core.wmem_max
  • net.ipv4.tcp_dsack
  • net.ipv4.tcp_sack
  • net.ipv4.tcp_timestamps
  • net.core.netdev_max_backlog

They can be modified with:

  • Quattor ;
  • YAIM ;
  • Manually by modifying the /etc/sysctl.conf file.


Recommended values

  • net.ipv4.tcp_rmem = 131072 1048576 2097152
  • net.ipv4.tcp_wmem = 131072 1048576 2097152
  • net.core.rmem_default = 1048576
  • net.core.wmem_default = 1048576
  • net.core.rmem_max = 2097152
  • net.core.wmem_max = 2097152
  • net.ipv4.tcp_dsack = 0
  • net.ipv4.tcp_sack = 0
  • net.ipv4.tcp_timestamps = 0
  • net.core.netdev_max_backlog = 10000


External links