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Configuring the ClearCase registry server to utilize multiple threads

Technote (FAQ)


How can I configure the IBM Rational ClearCase registry server (rgy_server) to run in multithreaded mode?


ClearCase version 9.0.1 and later can be configured to spawn a user-specified number of worker threads for rgy_server operations.


Your registry server host must be a multi-processor/multi-core machine to take advantage of this feature.

Stop ClearCase and then modify the albd_rt_params.conf file to uncomment the line with:


You can specify a numerical value to replace 4. The numerical value for the maximum number of worker threads is, in general, set depending on the activity on the registry server. Because the performance benefit will decline, do not set this value above 8.

The albd_rt_params.conf file can be found in /opt/rational/common/AdminDir/clearcase/config on Unix and Linux, and in RationalSDLC\ClearCase\config\services on Windows. If it does not already exist on Windows, you must create the file and enter a line for MAX_RGY_WORKER_THREADS with the numerical value you want.

After modifying and saving the config file, restart ClearCase. On startup, the registry server spawns the specified number of worker threads: for use in registry lookup operations if running ClearCase 9.0.1, and for use in all registry operations if running ClearCase,, or a later release.

To turn off multithreading, stop ClearCase, comment out the MAX_RGY_WORKER_THREADS line in the albd_rt_params.conf file, and restart ClearCase. The registry server then resumes legacy single-threaded lookup operations.

Document information

More support for: Rational ClearCase
ClearCase Registry

Software version:, 9.0.1,

Operating system(s): Linux, Solaris, Windows

Reference #: 2004423

Modified date: 13 September 2017

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