Obtaining view cache information

To examine a view’s cache information, use cleartool getcache –view.

About this task

Using getcache –view causes the view server to display information about the view cache sizes and hit rates. For example:

cleartool getcache –view r5_integration
Lookup cache:   29% full,   1121 entries ( 56.8K),  15832 requests,  75% hits
Readdir cache:   4% full,     24 entries ( 36.5K),   4159 requests,  83% hits
Fstat cache:    31% full,    281 entries (105.1K),  55164 requests, 100% hits
Object cache:   26% full,   1281 entries (176.6K),  40626 requests,  72% hits
Total memory used for view caches: 375.0Kbytes
The current view server cache limits are:
Lookup cache:             201312 bytes
Readdir cache:            838860 bytes
Fstat cache:              352296 bytes
Object cache:             704592 bytes
Total cache size limit:  2097152 bytes

You can use this information in several ways:
  • To determine whether to increase the view cache
  • To check the results after changing the view cache
  • To analyze other view server processes
The view cache includes these types of subcaches:
  • Lookup. Stores data used to accelerate mapping names to objects in the view.
  • Readdir. Stores data used to accelerate read-directory operations (for example, ls or dir) by the view.
  • Fstat. Stores data on file attributes used by the view.
  • Object. Stores data pertaining to objects used by the view.
To find the size of the total view cache, sum the sizes of these components.
Note: On computers running Linux® or the UNIX® system, you can force a view_server process to write cumulative cache-performance (and other) statistics to its log file, /var/adm/hcl/versionvault/log/view_log and then reset all the statistics accumulators to zero, by running the following command on the host where the view server runs:

kill –HUP view_server-process-ID

getcache –view provides this information:
  • Cache type
  • Percentage of the view cache being used
  • Number of entries in cache
  • Number of requests made
  • Percentage of cache hit rates
  • Amount of view cache memory being used
Here are some suggestions for analyzing this information:
  • Check the percentage of view cache being used. This value is very important.
    • If the hit rate is 90% or less and the view cache is 100% full, the view cache might be too small. The combination of a hit rate greater than 90% and view cache that is 100% full indicates that the cache size is about right.
    • If you are at less than 50% on every portion, your cache is probably too large.
  • Check this value more than once to be sure you are not seeing an anomalous, transitory value, such as for a newly started or restarted view server.
  • If you decide to increase the view cache size for a view, use the procedure described in Reconfiguring a view cache.