1. Performance Tuning Guide
  2. Environment Variables for Operating System Latches

Environment Variables for Operating System Latches

This topic is part of Tuning the Siebel Server for All UNIX and Linux Operating Systems.

Depending on the total number of tasks on the Siebel Server, you might need to set the environment variables described here in order to manage these loads. SIEBEL_OSD_NLATCH controls named latches and SIEBEL_OSD_LATCH controls unnamed latches. Latches, which are similar to mutexes (mutual exclusion objects), are used for communication between processes.

If SIEBEL_OSD_NLATCH and SIEBEL_OSD_LATCH are not defined, the values are 5000 and 1000, respectively. If these values are sufficient for the total number of tasks on the Siebel Server, then you do not need to set these variables. Do not set these variables to values lower than their default values.

Note: Before changing these variables, stop the Siebel Server using the stop_server command, then run the cleansync utility.

Set SIEBEL_OSD_NLATCH and SIEBEL_OSD_LATCH on the Siebel Server computer based on the following formulas (define the variables in the applicable profile for the Siebel Server):

  • SIEBEL_OSD_NLATCH = (7 times (cumulative MaxTasks for all components)) plus 1000

  • SIEBEL_OSD_LATCH = 1.2 times (cumulative MaxTasks for all components)

Assume, for example, that you have enabled two multithreaded server components on the same Siebel Server: SCCObjMgr_enu and WfProcMgr. For SCCObjMgr_enu, MaxTasks = 700 and, for WfProcMgr, MaxTasks = 150. In this example, the parameter values must be set as follows:

  • SIEBEL_OSD_NLATCH = 6950 = 7 times (700 plus 150) plus 1000

  • SIEBEL_OSD_LATCH = 1020 = 1.2 times (700 plus 150)

Note: Although the formulas presented here are expected to work for most deployments, in certain cases you might need to increase (for example, double) the values of these variables, and then monitor system behavior with the adjusted values. (An error message such as SBL-OSD-00217: Error exceeded maximum number of latches can sometimes be generated even when the variables are set according to the recommended formulas.