Hi Carmelo, Glad you to hear you are making progress. vm.drop_caches is disruptive, it will likely dump the cache for your local filesystem, mysql buffer, etc. Too aggressive vfs_cache_pressure values can cause similar problems. I found running the lru_size=clear command hourly gave about the same results as setting lru_max_age to one hour, YMMV.
regards, chris hunter yale hpc group On 05/08/2015 10:47 AM, Carmelo Ponti (CSCS) wrote: > Chris > > On Thu, 2015-05-07 at 11:56 -0400, Chris Hunter wrote: >> Hi Carmelo, >> >> What I found is once the local vfs cache is full, robinhood GET_INFO_FS >> speed drops. You can monitor (via /proc/meminfo) buffer, cached & slab >> memory usage when starting robinhood, you will see these values reach >> threshold after a time. Once this state is reached, parameters >> lru_max_age and vfs_cache_pressure are important. > > I see your point now. I increased vfs_cache_pressure to 125 and I > monitoring buffer, cached & slab as you suggested. I will check on > Monday and let you know. > >> You can also "flush" lustre cached ldlm locks by echoing "clear" to >> lru_size parameter. > > I scheduled this every hour in cron. > In addition on > https://urldefense.proofpoint.com/v2/url?u=https-3A__www.kernel.org_doc_Documentation_sysctl_vm.txt&d=AwICaQ&c=-dg2m7zWuuDZ0MUcV7Sdqw&r=d_G2h_sZYG4xtHMeKo8QgjDmOcMVdQvYgM-5Dri1AOY&m=2e-uiK2hYQaNO4gSQJmS-sbkcCSotxt3gGa7oYx5vds&s=j5zzS6pU4jPUsa4HvMfpFTrBqUXcffJvk08rLyK0sNg&e= > I'm reading about /proc/sys/vm/drop_caches. Do you think it could help > dropping slab objects and pagecache? (echo 3 >> /proc/sys/vm/drop_caches). > > Carmelo > ------------------------------------------------------------------------------ One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y _______________________________________________ robinhood-support mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/robinhood-support
