How can I limit z/OS Communications Server TCP/IP private and common storage use?

You can limit the PRIVATE and COMMON storage used by TCP/IP with the following -

Private (pool) storage

• REGION keyword in TCP/IP's start up JCL. The REGION size can also be overridden by use of installation exits such as IEFUSI. If used, you should also set limitations in the TCP/IP profile.

• TCP/IP Profile statement - GLOBALCONFIG POOLLIMIT xxK or xxM . Use of 0 means no limit and is the default

Common (ECSA) storage

• TCP/IP Profile statement - GLOBALCONFIG ECSALIMIT xxK or xxM . Use of 0 means no limit and is the default

If you choose to set TCP/IP GLOBALCONFIG POOL and ECSA limits you should consider -

• Monitoring TCP/IP storage use during your acceptable peak periods. This can be accomplished with the command D TCPIP,,STOR

  • Add a reasonable "fudge" factor to the observed maximum usage values.
    

  • Accommodate for temporary application "hang" conditions, where TCP/IP must buffer large amounts of inbound and outbound data.

• If you limit POOL storage, make sure you use a value that is lower than or equal to what your installation exit (IEFUSI) enforces.