[HBASE-10569] Co-locate meta and master

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.99.0
• Component/s: master, Region Assignment
• Hadoop Flags: Reviewed

Release Note

With this patch, HMaster is also a HRegionServer. Active master can serve some small tables per configuration (by default, it doesn't). Backup masters don't serve any region.

HMaster and HRegionServer share the same RPC server. That's transparent to clients since the master information is in ZK. The master and the regionserver also shares the same web UI server.

There is no protocol, or API change. So this feature is backward compatible, and rolling upgradable. In case it's needed, some configurations (HBASE-10815) will be added so that (1) we can have two web UI servers in the master (and backup masters), one for the master, and the other for the region server; (2) we can leave backup masters alone and don't put any regions on them. So that things are the same as before.

With this patch, the following configurations are removed (and not used any more):

hbase.master.dns.interface
hbase.master.dns.nameserver
hbase.master.port
hbase.master.ipc.address
hbase.master.zksession.recover.timeout
fail.fast.expired.active.master
hbase.master.handler.count

• Assignee: Jimmy Xiang
• Reporter: Jimmy Xiang
• Created: 19/Feb/14 17:00
• Updated: 06/Apr/18 17:50
• Resolved: 25/Mar/14 20:10

Description

I was thinking simplifying/improving the region assignments. The first step is to co-locate the meta and the master as many people agreed on HBASE-5487.

Issue Links

• breaks: HBASE-14644 Region in transition metric is broken
• is related to: HBASE-12034 If I kill single RS in branch-1, all regions end up on Master!
• is related to: HBASE-10923 Control where to put meta region
• relates to: HBASE-11146 HMaster instantiates both MasterCoprocessorHost and RegionServerCoprocessorHost
• relates to: HBASE-5487 Generic framework for Master-coordinated tasks