[jira] [Resolved] (HBASE-21065) Try ROW_INDEX_V1 encoding on meta table (fix bloomfilters on meta while we are at it)

["Michael Stack (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HBASE-21065?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Michael Stack resolved HBASE-21065.
-----------------------------------
    Fix Version/s: 3.0.0
     Hadoop Flags: Reviewed
     Release Note: 
Enables ROW_INDEX_V1 encoding on hbase:meta by default. Also enables blooms.

Will NOT enable encoding and blooms on upgrade. Operator will need to do this manually by editing hbase:meta schema (Or we provide a migration script to enable these configs -- out-of-scope for this JIRA).
       Resolution: Fixed

> Try ROW_INDEX_V1 encoding on meta table (fix bloomfilters on meta while we are at it)
> -------------------------------------------------------------------------------------
>
>                 Key: HBASE-21065
>                 URL: https://issues.apache.org/jira/browse/HBASE-21065
>             Project: HBase
>          Issue Type: Improvement
>          Components: meta, Performance
>            Reporter: Michael Stack
>            Assignee: Michael Stack
>            Priority: Major
>             Fix For: 3.0.0
>
>
> Some users end up hitting meta hard. Bulk is probably because our client goes to meta too often, and the real 'fix' for a saturated meta is splitting it, but the encoding that came in with HBASE-16213, ROW_INDEX_V1, could help in the near term. It adds an index on hfile blocks and helped improve random reads against user-space tables (less compares as we used index to go direct to requested Cells rather than look at each Cell in turn until we found what we wanted -- see RN on HBASE-16213 for citation).
> I also noticed code-reading that we don't enable blooms on hbase:meta tables; that could save some CPU and speed things up a bit too:
> {code}
>         // Disable blooms for meta.  Needs work.  Seems to mess w/ getClosestOrBefore.
>         .setBloomFilterType(BloomType.NONE)
> {code}
> This issue is about doing a bit of perf compare of encoding *on* vs current default (and will check diff in size of indexed blocks).
> Meta access is mostly random-read I believe (A review of a user's access showed this so at least for their workload). The nice addition, HBASE-19722 Meta query statistics metrics source, would help verify if it saw some usage on a prod cluster.
> If all is good, I'd like to make a small patch, one that could be easily backported, with minimal changes in it.
> As is, its all a little awkward as the meta table schema is hard-coded and meta is immutable -- stuff we'll have to fix if we want to split meta -- so in the meantime it requires a code change to enable (and a backport of HBASE-16213 -- this patch is in 1.4.0 only currently, perhaps that is enough). Code change to enable is small:
> {code}
> diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSTableDescriptors.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSTableDescriptors.java
> index 28c7ec3c2f..8f08f94dc1 100644
> --- a/hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSTableDescriptors.java
> +++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSTableDescriptors.java
> @@ -160,6 +160,7 @@ public class FSTableDescriptors implements TableDescriptors {
>          .setScope(HConstants.REPLICATION_SCOPE_LOCAL)
>          // Disable blooms for meta.  Needs work.  Seems to mess w/ getClosestOrBefore.
>          .setBloomFilterType(BloomType.NONE)
> +        .setDataBlockEncoding(org.apache.hadoop.hbase.io.encoding.DataBlockEncoding.ROW_INDEX_V1)
>          .build())
>        .setColumnFamily(ColumnFamilyDescriptorBuilder.newBuilder(HConstants.TABLE_FAMILY)
>          .setMaxVersions(conf.getInt(HConstants.HBASE_META_VERSIONS,
> {code}



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