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Todd Lipcon commented on HDFS-5399: ----------------------------------- The javadoc warnings are currently showing up on all builds (HADOOP-10325 should address this). I'll commit this to trunk, branch-2, and branch-2.3 > Revisit SafeModeException and corresponding retry policies > ---------------------------------------------------------- > > Key: HDFS-5399 > URL: https://issues.apache.org/jira/browse/HDFS-5399 > Project: Hadoop HDFS > Issue Type: Improvement > Affects Versions: 2.3.0 > Reporter: Jing Zhao > Assignee: Jing Zhao > Attachments: HDFS-5399.000.patch, HDFS-5399.001.patch, > HDFS-5399.003.patch, hdfs-5399.002.patch > > > Currently for NN SafeMode, we have the following corresponding retry policies: > # In non-HA setup, for certain API call ("create"), the client will retry if > the NN is in SafeMode. Specifically, the client side's RPC adopts > MultipleLinearRandomRetry policy for a wrapped SafeModeException when retry > is enabled. > # In HA setup, the client will retry if the NN is Active and in SafeMode. > Specifically, the SafeModeException is wrapped as a RetriableException in the > server side. Client side's RPC uses FailoverOnNetworkExceptionRetry policy > which recognizes RetriableException (see HDFS-5291). > There are several possible issues in the current implementation: > # The NN SafeMode can be a "Manual" SafeMode (i.e., started by administrator > through CLI), and the clients may not want to retry on this type of SafeMode. > # Client may want to retry on other API calls in non-HA setup. > # We should have a single generic strategy to address the mapping between > SafeMode and retry policy for both HA and non-HA setup. A possible > straightforward solution is to always wrap the SafeModeException in the > RetriableException to indicate that the clients should retry. -- This message was sent by Atlassian JIRA (v6.1.5#6160)