Thanks Nick! Unfortunately, I'm stuck with 0.98. Perhaps it's something I should look into backporting if all else fails...
Would also bigger great if anyone had any insight in the differences between offheap and file:/ in terms of configuration. When RAM to tmpfs was used as the workaround for the RS issue, was MaxDirectMemory size still set? Thanks! On Oct 6, 2015 4:03 PM, "Nick Dimiduk" <ndimi...@apache.org> wrote: > Configuring offheap cache in 0.98 is a huge PITA. There are some example > configs [0] linked from my old blog post [1], maybe that's a starting > point? I also worked with our docs team to get this explained [2] in a > somewhat useful way, using an algorithm/formula as the basis of the > explanation. That algorithm was eventually implemented into Ambari's Stack > Advisor script [3], so if you're really feeling brave you can try to > extract it from there. > > But really, you should upgrade to 1.x and enjoy Stack's nice work on making > it simpler to configure. > > Good luck, > -n > > [0]: https://github.com/ndimiduk/perf_blockcache > [1]: http://www.n10k.com/blog/blockcache-showdown/ > [2]: > > http://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.3.0/bk_Sys_Admin_Guides/content/ref-db219cd6-c586-49c1-bc56-c9c1c5475276.1.html > [3]: > > https://github.com/apache/ambari/blob/trunk/ambari-server/src/main/resources/stacks/HDP/2.2/services/stack_advisor.py#L552-L579 > > On Tue, Oct 6, 2015 at 11:36 AM, Anthony Nguyen < > anthony.an.ngu...@gmail.com > > wrote: > > > Hi all, > > > > I'm running HBase 0.98, with the complicated percentage.in.combinedcache > > setting. What's the best way to set the percentage.in.combinedcache > setting > > when using a file on SSD storage as the location for ioengine? The SSD > > drive is dedicated for the cache. I don't want to modify the > LruBlockCache > > settings at all, keeping it available for index + bloom and just add the > L2 > > SSD cache for storage for the data blocks (not the raw L1+L2 method). > > > > My confusion is in how I should best modify the > percentage.in.combinedcache > > setting. HBASE-11520 makes things much clearer, but unfortunately it > isn't > > in 0.98. To me, it doesn't make much sense to have L1 be set to > > hbase.bucketcache.size (100G) * (1.0 - > > hbase.bucketcache.percentage.in.combinedcache (default=0.9) = 1G when I > > want the L1 to be the same as it was prior to bucketcache > > (hfile.block.cache.size * heap). > > > > Also, I don't want to have any direct addressing of memory since my > offheap > > is completely on SSD. Does this mean I shouldn't change > > XX:MaxDirectMemorySize? > > > > Could someone sanity check these settings for me? Thanks! > > > > 30 GB RAM > > ~120 GB SSD > > HBASE_REGIONSERVER_OPTS -Xms17G -Xmx17G > > XX:MaxDirectMemorySize <- Don't touch since we're not using direct byte > > buffers, right? > > > > <property> > > <name>hbase.bucketcache.ioengine</name> > > <value>file:/mnt/foo/bar</value> > > </property> > > <property> > > <name>hbase.bucketcache.percentage.in.combinedcache</name> > > <value>0.9</value> > > </property> > > > > <property> > > <name>hfile.block.cache.size</name> > > <value>0.6</value> > > </property> > > > > <property> > > <name>hbase.bucketcache.size</name> > > <value>102400</value> > > </property> > > >
