[ 
https://issues.apache.org/jira/browse/HBASE-19024?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Andrew Purtell updated HBASE-19024:
-----------------------------------
     Environment:     (was: 
)
    Release Note: The default durability setting for the synchronous WAL is 
Durability.SYNC_WAL, which triggers HDFS hflush() to flush edits to the 
datanodes. We also support Durability.FSYNC_WAL, which instead triggers HDFS 
hsync() to flush _and_ fsync edits. This change introduces the new 
configuration setting "hbase.wal.hsync", defaulting to FALSE, that if set to 
TRUE changes the default durability setting for the synchronous WAL to  
FSYNC_WAL.

> Configurable default durability for synchronous WAL
> ---------------------------------------------------
>
>                 Key: HBASE-19024
>                 URL: https://issues.apache.org/jira/browse/HBASE-19024
>             Project: HBase
>          Issue Type: Improvement
>          Components: wal
>            Reporter: Vikas Vishwakarma
>            Assignee: Harshal Jain
>            Priority: Critical
>             Fix For: 3.0.0, 2.1.0, 1.5.0
>
>         Attachments: HBASE-19024-master.v10.patch, 
> HBASE-19024.branch-1.2.001.patch, HBASE-19024.branch-1.2.002.patch, 
> HBASE-19024.branch-1.2.003.patch, HBASE-19024.branch-1.2.004.patch, 
> HBASE-19024.branch-1.2.005.patch, branch-1.branch-1.patch, 
> branch-1.v1.branch-1.patch, master.patch, master.v2.patch, master.v3.patch, 
> master.v5.patch, master.v5.patch, master.v6.patch, master.v9.patch
>
>
> At present we do not have an option to hsync WAL edits to the disk for better 
> durability. In our local tests we see 10-15% latency impact of using hsync 
> instead of hflush which is not very high.  
> We should have a configurable option to hysnc WAL edits instead of just 
> sync/hflush which will call the corresponding API on the hadoop side. 
> Currently HBase handles both SYNC_WAL and FSYNC_WAL as the same calling 
> FSDataOutputStream sync/hflush on the hadoop side. This can be modified to 
> let FSYNC_WAL call hsync on the hadoop side instead of sync/hflush. We can 
> keep the default value to sync as the current behavior and hsync can be 
> enabled based on explicit configuration.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

Reply via email to