Thanks, it all makes sense now. Cheers.
---- Saad On Mon, Feb 19, 2018 at 5:40 AM Anoop John <[email protected]> wrote: > Hi > Seems you have write ops happening as you mentioned abt > minor compactions. When the compaction happens, the compacted file's > blocks will get evicted. Whatever be the value of > 'hbase.rs.evictblocksonclose'. This config comes to play when the > Store is closed. Means the region movement is happening or split and > so a close on stores. Also the table might get disabled or deleted. > All such store close cases this config comes to picture. But minor > compactions means there will be evictions. These are not via the > eviction threads which monitor the less spaces and select LRU blocks > for eviction. This is done by the compaction threads. That is why you > can see the evict ops (done by Eviction thread) is zero but the > #evicted blocks are there. Those might be the blocks of the compacted > away files. Hope this helps you to understand what is going on. > > -Anoop- > > > On Mon, Feb 19, 2018 at 5:25 AM, Saad Mufti <[email protected]> wrote: > > Sorry I meant BLOCKCACHE => 'false' on the one column family we don't > want > > getting cached. > > > > Cheers. > > > > ---- > > Saad > > > > > > On Sun, Feb 18, 2018 at 6:51 PM, Saad Mufti <[email protected]> > wrote: > > > >> Hi, > >> > >> We have an HBase system running HBase 1.3.1 on an AWS EMR service. Our > >> BucketCache is configured for 400 GB on a set of attached EBS disk > volumes, > >> with all column families marked for in-memory in their column family > >> schemas using INMEMORY => 'true' (except for one column family we only > ever > >> write to, so we set BUCKETCACHE => 'false' on that one). > >> > >> Even though all column families are marked INMEMORY, we have the > following > >> ratios set: > >> > >> "hbase.bucketcache.memory.factor":"0.8", > >> > >> "hbase.bucketcache.single.factor":"0.1", > >> > >> > >> "hbase.bucketcache.multi.factor":"0.1", > >> > >> Currently the bucket cache shows evictions even though it has tons of > free > >> space. I am trying to understand why we get any evictions at all? We do > >> have minor compactions going on, but we have not set > hbase.rs.evictblocksonclose > >> to any value and from looking at the code, it defaults to false. The > total > >> bucket cache size is nowhere near any of the above limits, in fact on > some > >> long running servers where we stopped traffic, the cache size went down > to > >> 0. Which makes me think something is evicting blocks from the bucket > cache > >> in the background. > >> > >> You can see a screenshot from one of the regionserver L2 stats UI pages > at > >> https://imgur.com/a/2ZUSv . Another interesting thing to me on this > page > >> is that it has non-zero evicted blocks but says Evictions: 0 > >> > >> Any help understanding this would be appreciated. > >> > >> ---- > >> Saad > >> > >> >
