[
https://issues.apache.org/jira/browse/HBASE-11307?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14020669#comment-14020669
]
stack commented on HBASE-11307:
-------------------------------
>From [~zjushch] in description for HBASE-7404:
{quote}We have studied and test SlabCache first, but the result is bad, because:
SlabCache use SingleSizeCache, its use ratio of memory is low because kinds of
block size, especially using DataBlockEncoding
SlabCache is uesd in DoubleBlockCache, block is cached both in SlabCache and
LruBlockCache, put the block to LruBlockCache again if hit SlabCache , it
causes CMS and heap fragment don't get any better{quote}
The patch in HBASE-4089 has work to dump stats on slabcache and bucketcache and
graphically illustrates difference in their sophistication. I was sort of
hoping for some perf numbers definitively showing it worse before moving to
purge it but its hard to do (so many combinations to try!).
So I'm for just making a call. Intellectually we can see the its deploy type
using DoubleBlockCache is not going to be as good as CombinedBlockCache for GC
and it will take a bunch of work, that no one of us has done nor is likely to
do, trying SlabCache in different deploy scenarios; e.g. use SlabCache in
CombinedBlockCache deploy.
So, in the name of simplification and being able to narrow our limited
attention span, at first I was thinking just talk down SlabCache but
better/cleaner, lets just call it a stepping stone and just remove it
altogether. +1 on patch. Needs to include hardening of the just-added doc in
refguide which discourages SlabCache to instead do violent discouragement
(noting gone in 1.0).
> Deprecate SlabCache
> -------------------
>
> Key: HBASE-11307
> URL: https://issues.apache.org/jira/browse/HBASE-11307
> Project: HBase
> Issue Type: Sub-task
> Components: regionserver
> Reporter: Nick Dimiduk
> Assignee: Nick Dimiduk
> Fix For: 0.99.0
>
> Attachments: HBASE-11307.00.patch
>
>
> BucketCache is more feature-full than SlabCache. My performance testing
> indicates that SlabCache doesn't perform well as memory footprint grows. I
> believe BucketCache is seeing more production usage than SlabCache at this
> point. I suggest we consolidate on BucketCache.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
