[HBASE-5603] rolling-restart.sh script hangs when attempting to detect expiration of /hbase/master znode.

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 0.92.0, 0.94.0, 0.95.2
• Fix Version/s: 0.94.0, 0.95.0
• Component/s: Zookeeper
• Hadoop Flags: Reviewed
• Assignee: Jonathan Hsieh
• Reporter: Jonathan Hsieh
• Created: 20/Mar/12 07:53
• Updated: 18/Sep/13 22:23
• Resolved: 20/Mar/12 22:53

Description

Due to bugfix ZOOKEEPER-1059 (ZK 3.4.0+), the rolling-restart.sh script will hang when attempting to make sure the /hbase/master znode is deleted.

Here's the code

# make sure the master znode has been deleted before continuing
    zparent=`$bin/hbase org.apache.hadoop.hbase.util.HBaseConfTool zookeeper.znode.parent`
    if [ "$zparent" == "null" ]; then zparent="/hbase"; fi
    zmaster=`$bin/hbase org.apache.hadoop.hbase.util.HBaseConfTool zookeeper.znode.master`
    if [ "$zmaster" == "null" ]; then zmaster="master"; fi
    zmaster=$zparent/$zmaster
    echo -n "Waiting for Master ZNode ${zmaster} to expire"
    while bin/hbase zkcli stat $zmaster >/dev/null 2>&1; do
      echo -n "."
      sleep 1
    done
    echo #force a newline

Prior to ZOOKEEPER-1059, stat on a null znode would NPE and cause zkcli to exit with retcode 1. Afterwards, the null is caught, zkcli will exit with 0 in the case where the znode is present and in the case where it does not exist.

Issue Links

• depends upon: HBASE-2418 add support for ZooKeeper authentication
• is related to: HBASE-5589 Add of the offline call to the Master Interface