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Ship it! Ship It! - Alejandro Fernandez On April 21, 2016, 10:24 p.m., Jayush Luniya wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/46544/ > ----------------------------------------------------------- > > (Updated April 21, 2016, 10:24 p.m.) > > > Review request for Ambari, Alejandro Fernandez, Robert Nettleton, and Sumit > Mohanty. > > > Bugs: AMBARI-16028 > https://issues.apache.org/jira/browse/AMBARI-16028 > > > Repository: ambari > > > Description > ------- > > 1. During Namenode HA blueprint deployment, we configure the name nodes to > start in active/standby mode based on the following properties > { > "hadoop-env": { > "properties" : { > "dfs_ha_initial_namenode_active" : "host1", > "dfs_ha_initial_namenode_standby" : "host2” > } > } > } > 2. The current logic is to always bootstrap the name node marked as standby. > 3. This will lead to the Namenode marked as Standby to never start under the > following situation > > - Cluster is deployed successfully > - Both name nodes are stopped > - Start the name node marked as standby. Namenode will never start. > - This is because the standby name node will try to bootstrap again. > - However to bootstrap a name node an active name node is required. Based on > the HDFS logic the first step done when bootstrapping is to connect to the > Active Namenode. > - Also there is no need to bootstrap here as the name node should already be > bootstrapped and should come back up as “Active" > > > Fix: > - The fix is to maintain a bootstrap marker file (similar to the way we keep > a name node formatted marker file) > - In the INITIAL_START phase (during cluster deployment) we will always force > bootstrap so as to enforce the name node marked as Standby to wait for the > Active name node to come up, bootstrap and start in STANDBY node. > - Once we are out of INITIAL_START phase, we will bootstrap only if this name > node has not been bootstrapped in the past. > - We will not enforce bootstrapping only in the INITIAL_START phase because > there is a possibility during cluster deployment that both name nodes don’t > start and hence bootstrapping out of INITIAL_START phase would be required in > this case. > > > Diffs > ----- > > > ambari-server/src/main/resources/common-services/HDFS/2.1.0.2.0/package/scripts/hdfs_namenode.py > 8b6c924 > > ambari-server/src/main/resources/common-services/HDFS/2.1.0.2.0/package/scripts/params_linux.py > d8ff3c5 > ambari-server/src/test/python/stacks/2.0.6/HDFS/test_namenode.py 1c08d57 > > Diff: https://reviews.apache.org/r/46544/diff/ > > > Testing > ------- > > Verified scenarios on live cluster. > > mvn clean test -DskipSurefireTests > [INFO] > ------------------------------------------------------------------------ > [INFO] BUILD SUCCESS > [INFO] > ------------------------------------------------------------------------ > [INFO] Total time: 54.784s > [INFO] Finished at: Thu Apr 21 15:22:52 PDT 2016 > [INFO] Final Memory: 64M/1172M > [INFO] > ------------------------------------------------------------------------ > > > Thanks, > > Jayush Luniya > >
