hbase-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Anoop Sam John (JIRA)" <j...@apache.org>
Subject [jira] [Created] (HBASE-19357) Bucket cache no longer L2 for LRU cache
Date Tue, 28 Nov 2017 05:38:00 GMT
Anoop Sam John created HBASE-19357:

             Summary: Bucket cache no longer L2 for LRU cache
                 Key: HBASE-19357
                 URL: https://issues.apache.org/jira/browse/HBASE-19357
             Project: HBase
          Issue Type: Sub-task
            Reporter: Anoop Sam John
            Assignee: Anoop Sam John
             Fix For: 2.0.0-beta-1

When Bucket cache is used, by default we dont configure it as an L2 cache alone. The default
setting is combined mode ON where the data blocks to Bucket cache and index/bloom blocks go
to LRU cache. But there is a way to turn this off and make LRU as L1 and Bucket cache as a
victim handler for L1. It will be just L2.   
After the off heap read path optimization Bucket cache is no longer slower compared to L1.
We have test results on data sizes from 12 GB.  The Alibaba use case was also with 12 GB and
they have observed a ~30% QPS improve over the LRU cache.
This issue is to remove the option for combined mode = false. So when Bucket cache is in use,
data blocks will go to it only and LRU will get only index /meta/bloom blocks.   Bucket cache
will no longer be configured as a victim handler for LRU.

Note : WHen external cache is in use, there only the L1 L2 thing comes. LRU will be L1 and
external cache act as its L2. That make full sense.

This message was sent by Atlassian JIRA

View raw message