Eric Sirianni created HDFS-5769: ----------------------------------- Summary: Bootstrap a write pipeline from read-only replicas Key: HDFS-5769 URL: https://issues.apache.org/jira/browse/HDFS-5769 Project: Hadoop HDFS Issue Type: Improvement Components: hdfs-client, namenode Affects Versions: 2.4.0 Reporter: Eric Sirianni
HDFS-1606 added the capability for the {{DFSClient}} to add DataNodes to an existing write pipeline. HDFS-2832 and HDFS-5318 introduce read-only replicas to HDFS. This JIRA proposes using the HDFS-1606 {{addDatanode2ExistingPipeline()}} capability to enable recovering in scenarios where only read-only replicas are available (i.e. all read-write replicas are offline). The following scenarios should be supported: # _Recovering_ an initial write pipeline with repcount=1 (see HDFS-5434) when the datanode hosting the r/w replica fails (but r/o replicas are available) # _Constructing_ an append pipeline for a block where the r/w replica is offline (but r/o replicas are available) In both cases, a pipeline of length 0 can be "bootstrapped" to a pipeline of length 1 using available r/o replicas. -- This message was sent by Atlassian JIRA (v6.1.5#6160)