Description of problem: nscd does not appear to be caching anything in RHEL 4.4. Version-Release number of selected component (if applicable): nscd-2.3.4-2.25 How reproducible: Every time. Steps to Reproduce: 1.In /etc/nscd.conf, enable logging to /var/log/nscd.log and set debug level to 99 2. Restart nscd 3. Run attched perl script Actual results: grep 'GETPWBYNAME' /var/log/nscd.log | wc -l ...will show positive values after running script, however... The output of 'nscd -g' will show 0% cache hit rate Expected results: 'nscd -g' should show a 99% (or 100%) cache hit rate Additional info: This works fine on RHEL 3
Created attachment 155842 [details] a script to exercise nscd by repeatedly querying the passwd & group tables
Same results with nscd-2.3.4-2.36 as well.
In RHEL4 nscd.conf defaults to shared yes and persistent yes for all databases. This means that nscd's cache is read-only mapped in applications and they search the cache directly instead of asking nscd to do the cache search for them. Only when a request (or a negative search entry) is not found in the cache, apps ask nscd over the socket and nscd does the search and adds it to the cache. nscd -g stats only report requests that actually made it to nscd, it can't see requests answered just by cache search within the applications.