hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From donmai <dood...@gmail.com>
Subject Re: hbase.bucketcache.percentage.in.combinedcache with ioengine=<FILE ON SSD> on HBase 0.98
Date Tue, 06 Oct 2015 20:29:17 GMT
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" <ndimiduk@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.nguyen@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>
> >
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message