If HiRDB receives many connection requests simultaneously, the Listen queue used by the HiRDB server may become insufficient to handle them, in which case the KFPA11723-E message is displayed to the client-side applications to notify them of the error. When this occurs, use an OS command to determine whether or not the Listen queue is insufficient. You can determine that the Listen queue is insufficient if the frequency of insufficient Listen queuing is greater than before the errors began and the errors continue to increase. For details about making this determination, refer to the OS documentation.
If you have determined that the Listen queue is insufficient, enlarge the Listen queue on the HiRDB server machine. To enlarge the Listen queue, have it steadily increase to the 200 level each. However, if the OS cannot enlarge the Listen queue, or if increasing up to the specified maximum number of concurrent connections does not stop the errors, take a measure such as increasing the HiRDB connection processing power by increasing the processing power of the server machine (such as by adding CPUs) or reduce the number of connection requests to HiRDB by reducing the maximum number of concurrent connections.
Table 21-5 shows the parameters (for Linux, option settings file) that are to be changed when the value for the Listen queue is changed. For details about the commands whose parameters are to be changed and how to use them, see the applicable OS documentation.
Table 21-5 Parameters for changing the value for the Listen queue
OS | Parameter to be changed* |
---|---|
HP-UX | /dev/tcp tcp_conn_request_max |
Solaris | /dev/tcp tcp_conn_req_max_q, /dev/tcp tcp_conn_req_max_q0 |
AIX 5L | somaxconn |
Linux | /proc/sys/net/ ipv4.tcp_max_syn_backlog |