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    ORA-12520: TNS:listener could not find available handler for requested

    • Article Type: General
    • Product: Aleph
    • Product Version: 19.01

    Description:
    We are running p_manage_01 on our Production database.

    We find that the $data_scratch/p_manage_01_a_1 - p_manage_01_a_6 processes are processing normally, but p_manage_01_a_7 and p_manage_01_a_8 are just going rapidly on to the next cycle. (This can be seen in the p_manage_01_a.cycles file.)

    The fcl03 $data_scratch/p_manage_01_a_7.log and p_manage_01_a_8.log's -- which are much bigger than the 1-6 logs -- have errors like this:

    Oracle error: handle_connection
    ORA-12520: TNS:listener could not find available handler for requested type of server
    ^[[2J^[[H^[[0m

    {Note: It sometimes appears in the truncated form:

    ORA-12520: TNS:listener could not find available handler for requested }

    p_manage_01 was initially run with 8 processes. We tried it with 6, then 4, then 3 processes. Though it took a bit longer with 3 than with 8 processes, it ultimately failed (in the p_manage_01_c or p_manage_01_d1 steps, with the same listener error) in each case.

    Resolution:
    It was determined that Oracle was hitting a max-process limit of 150.

    The immediate solution was to stop/restart Aleph and Oracle.

    The maximum number of Oracle processes is set in the $ORACLE_HOME/dbs/init<$ORACLE_SID>.ora file. (For example, "initaleph0.ora")

    I find this in the $ORACLE_HOME/dbs/initaleph0.ora for the old Oracle:

    processes=800

    while the $ORACLE_HOME/dbs/initaleph0.ora for the new Oracle has:

    processes=150

    This # processes needs to be increased to 400 or 800:

    200 for (recommended value for a 'small' system),
    400 for (recommended value for a 'medium' system).


    • Article last edited: 2/19/2014