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1 Reply Latest reply: Sep 6, 2011 4:44 AM by RenévanWijk RSS

TCP Tuning Perameters.

863710 Newbie
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Dear support,

How to find out current settings of below TCP tuning perameters for solaris 10, and how can we change or upgrade these perameters your urgent responce will be highly appreciable .

sq_max_size
tcp_conn_req_max_q
tcp_conn_req_max_q0

Thanks.
  • 1. Re: TCP Tuning Perameters.
    RenévanWijk Oracle ACE
    Currently Being Moderated
    Problem concerning TCP has to do wait TCP connections going into TIME_WAIT state.

    To see if there are any sockets in the TIME_WAIT state you can use
    netstat -a | grep TIME_WAIT | wc -l
    When the number of TCP connections in TIME_WAIT state approach the maximum number of file descriptions your application throughput will suffer degradation

    To determine the time wait interval you can use:
    /usr/sbin/ndd /dev/tcp tcp_time_wait_interval
    Try setting this value to 60000 milliseconds
    /usr/sbin/ndd -set /dev/tcp tcp_time_wait_interval 60000
    Note that some values cannot be set using the ndd command but must be changed in /etc/system.
    To check which commands are read-write or read-only you can use
    ndd /dev/tcp \?
    On solaris 10 you might also want to change ipc1_conn_hash_size (controls the hash table to locate the
    TCP socket data structure in the kernel) by changing the /etc/system file
    set ip:ipcl_conn_hash_size=8192
    Note that the parameter tcp_conn_req_max_q controls the maximum allowed number of completed connections
    waiting to return from an accept call. This parameter should only be increased if the system is dropping connections.
    To determine the number of connection drops you can use:
    netstat -s | grep tcpListenDrop
    If the system is dropping connection try increasing the value to 1024.

    If your machine is to host a HTTP server, it is wise to increase the open file descriptor hard and soft limits, for example to 4096
    set rlim_fd_cur=4096
    set rlim_fd_max=4096
    More information on tunable parameters can be found here: http://download.oracle.com/docs/cd/E19253-01/817-0404/
    and http://download.oracle.com/docs/cd/E11035_01/wls100/perform/OSTuning.html

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