[HBASE-25237] 'hbase master stop' shuts down the cluster, not the master only

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0-alpha-1, 1.7.0, 2.4.0, 2.2.7, 2.3.4
• Hadoop Flags: Reviewed

Release Note

`hbase master stop` should shutdown only master by default.
1. Help added to `hbase master stop`:
To stop cluster, use `stop-hbase.sh` or `hbase master stop --shutDownCluster`

2. Help added to `stop-hbase.sh`:
stop-hbase.sh can only be used for shutting down entire cluster. To shut down (HMaster|HRegionServer) use hbase-daemon.sh stop (master|regionserver)

• Assignee: Lokesh Khurana
• Reporter: Michael Stack
• Created: 02/Nov/20 23:24
• Updated: 30/Nov/20 11:24
• Resolved: 27/Nov/20 11:06

Description

This is confusing (an operator at place-of-employment shut down a massive cluster mistakenly thinking he was shutting down the master only).

If I run 'hbase master --help', it says unsupported and then dumps out:

org.apache.hbase.thirdparty.org.apache.commons.cli.UnrecognizedOptionException: Unrecognized option: --help
 at org.apache.hbase.thirdparty.org.apache.commons.cli.Parser.processOption(Parser.java:383)
 at org.apache.hbase.thirdparty.org.apache.commons.cli.Parser.parse(Parser.java:210)
 at org.apache.hbase.thirdparty.org.apache.commons.cli.Parser.parse(Parser.java:88)
 at org.apache.hadoop.hbase.master.HMasterCommandLine.run(HMasterCommandLine.java:89)
 at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:76)
 at org.apache.hadoop.hbase.util.ServerCommandLine.doMain(ServerCommandLine.java:149)
 at org.apache.hadoop.hbase.master.HMaster.main(HMaster.java:2945)
Usage: Master [opts] start|stop|clear
 start Start Master. If local mode, start Master and RegionServer in same JVM
 stop Start cluster shutdown; Master signals RegionServer shutdown
 clear Delete the master znode in ZooKeeper after a master crashes
 where [opts] are:
 --minRegionServers=<servers> Minimum RegionServers needed to host user tables.
 --localRegionServers=<servers> RegionServers to start in master process when in standalone mode.
 --masters=<servers> Masters to start in this process.
 --backup Master should start in backup mode

 

... so the 'help' is clear that its the cluster that goes down, not just the master – but that is hardly compensates for the unexpected behavior.

 

'hbase master stop' is actually what is used internally you run stop-hbase.sh.

 

Stopping the cluster when your run 'hbase master stop' is actually very old behavior. Its still confusing though. We could change this.

If I run 'hbase regionserver stop', it does this:

System.err.println(
  "To shutdown the regionserver run " +
  "hbase-daemon.sh stop regionserver or send a kill signal to " +
  "the regionserver pid");

I'd think we could make improvement here. We could do something like the RS output if user types 'hbase master stop' at a minimum requiring operator add a '–force' flag if they want the cluster to go down or point them to a new hbase cluster stop/hbase cluster start or point them at stop-hbase.sh.  Should also change mode so 'hbase master stop' stops the master and not the cluster (there was no stopMaster when the 'hbase master stop' was added originally – but there is one now).

 

Issue Links

• links to: GitHub Pull Request #2705
• links to: GitHub Pull Request #2713