Add embedded journal

Description

Currently, Alluxio relies on a UFS to persistently log metadata changes so that once we acknowledge a change to the client, the change will never be lost. This works fine when the Alluxio masters are co-located with HDFS, but can hurt performance when using a remote UFS or a UFS which doesn't support streaming writes. This jira proposes a journal mechanism which doesn't rely on a UFS for persistence, instead writing logs to local disks on masters.

Environment

None

Status

Assignee

Lu Qiu

Reporter

Lu Qiu

Labels

None

Components

Affects versions

Priority

Major
Configure