Tuning Linux OS Kernel Parameters for Oracle WebCache

This note is to increase the kernel parameters for better performance in tcp connection on Linux red-hat.

First of all verify the system requirements to install WebCache in oracle.com, and check other required parameters like “kernel.sem” and  “kernel.shmall”.

Tuning:

Add in /etc/sysctl.conf

net.ipv4.nonlocal_bind = 1
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_max_tw_buckets = 2000000
net.ipv4.tcp_sack = 0
net.ipv4.tcp_window_scaling = 0
net.ipv4.tcp_keepalive_time = 900
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_keepalive_intvl = 20
net.ipv4.tcp_fin_timeout = 10
net.ipv4.tcp_syn_retries = 5
net.ipv4.tcp_synack_retries = 5
net.ipv4.tcp_retries2 = 15
net.ipv4.tcp_wmem = 10000000 10000000 10000000
net.ipv4.tcp_rmem = 10000000 10000000 10000000
net.ipv4.tcp_mem = 10000000 10000000 10000000
net.core.wmem_default = 10000000
net.core.wmem_max = 10000000
net.core.rmem_default = 10000000
net.core.rmem_max = 10000000
net.core.hot_list_length = 20000
net.core.optmem_max = 10000000
net.core.hot_list_length = 20000
net.core.optmem_max = 10000000
net.core.netdev_max_backlog = 300000

 

NOTE:

You need to check with your network admin for firewall timeout value.  Then you should modify kernel parameter net.ipv4.tcp_keepalive_time to a value lower than the firewall timeout values. This should give the TCP keepalive a chance to keep the connection alive.

On Linux, the keepalive procedures use three user-driven variables:

tcp_keepalive_time : How often TCP sends out keepalive messages when keepalive is enabled. Default is 7200 seconds.

tcp_keepalive_intvl : How frequent probes are retransmitted, when a probe isn’t acknowledged. Default :75 seconds

tcp_keepalive_probes : How many keepalive probes TCP will send, until it decides that the connection is broken. Default:9 seconds

 

If you need more information about webcache tuning : http://www.help2ora.com/index.php/2011/08/16/oracle-portal-performance

 

Good Luck !

 

4 Comments to "Tuning Linux OS Kernel Parameters for Oracle WebCache"

  1. 08/21/2011 - 1:58 AM | Permalink

    Hello There. I found your blog using msn. This is a really well written article. I will be sure to bookmark it and come back to read more of your useful information. Thanks for the post. I will definitely comeback.

  2. 10/03/2011 - 1:43 AM | Permalink

    Thanks alot! This is what i was looking for

  3. Tina Rowe's Gravatar Tina Rowe
    04/13/2012 - 2:42 PM | Permalink

    Great Article…. do you know of anywhere that has the same information for windows that you provide for Linux for the Webcache?

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