June 19 2010

Find top Informix SQL session by using UNIX pid

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Do you have difficulty on finding top informix session by UNIX pid (process id)?


It is common DBA always been asked “Why informix oninit processes always in UNIX top list? What are they doing?”

In general and with common sense, if an UNIX/Linux box is hosting a (or multiple) Informix database instance(s).   Normally, most of the machine resource (CPU, memory, Disk I/O) will be consumed by Informix instance(s). Oninit processes are the daemons that serve application requests (SQL request) and interact between application and making OS system calls.

Logically, oninit processes can relate to Informix session id.  I have following steps to show how it can be done.

Note:  This may not 100% correct, as user threads are switching between CPU VPs from time to time. You may take as reference to capture repeated patterns.