Tuning the Siebel Server for AIX

This topic is part of Tuning Siebel CRM for AIX.

AIX provides several environment variables that can be tuned to optimize Siebel Server performance. These environment variables and their values are used as start parameters when the Siebel Server is started. The following tables describe each of these environment variables and their recommended settings.

Note: For more information about tuning the Siebel Server, see Tuning the Siebel Server for All UNIX and Linux Operating Systems.

Environment Variable	Value	Description
AIXTHREAD_SCOPE	S	Controls contention scope. S signifies system-based contention scope (1:1).
AIXTHREAD_MNRATIO	1:1	Controls the M:N ratio of number of kernel threads that must be employed to handle runnable pthreads.
AIXTHREAD_MUTEX_DEBUG	OFF	Maintains a list of active mutexes for use by the debugger.
AIXTHREAD_RWLOCK_DEBUG	OFF	Maintains a list of read-write locks for use by the debugger.
AIXTHREAD_COND_DEBUG	OFF	Maintains a list of condition variables for use by the debugger.

Environment Variable	Value	Description
SPINLOOPTIME	1000	Controls the number of times to retry a busy lock before yielding to another processor.
YIELDLOOPTIME	>=n A number greater than or equal to the number of processors.	Controls the number of times to yield the processor before blocking on a busy lock (only for libpthreads). Set this variable, at the minimum, equal to the number of processors on the computer.
MALLOCOPTIONS	buckets,considersize,mu ltiheap:4	Include in the value an integer representing the number of processors on this computer. In this case, the value 4 would be used for a four-processor computer.
LDR_CNTRL	Example values: LOADPUBLIC@MAXDATA=0x50000000 (this value, which specifies five segments, sets a maximum process size of 1.25 GB) LOADPUBLIC@MAXDATA=0x60000000 (this value, which specifies six segments, sets a maximum process size of 1.5 GB)	The LOADPUBLIC option directs the system loader to load all modules requested by an application into the global shared library segment. Set LDR_CNTRL in the environment of the user, or, preferably, in the shell script that launches the executable program that needs the extra memory.