[jira] [Updated] (HDFS-13132) Ozone: Handle datanode failures in Storage Container Manager
[ https://issues.apache.org/jira/browse/HDFS-13132?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Mukul Kumar Singh updated HDFS-13132: - Attachment: HDFS-13132-HDFS-7240.002.patch > Ozone: Handle datanode failures in Storage Container Manager > > > Key: HDFS-13132 > URL: https://issues.apache.org/jira/browse/HDFS-13132 > Project: Hadoop HDFS > Issue Type: Sub-task > Components: ozone >Affects Versions: HDFS-7240 >Reporter: Mukul Kumar Singh >Assignee: Mukul Kumar Singh >Priority: Major > Fix For: HDFS-7240 > > Attachments: HDFS-13132-HDFS-7240.001.patch, > HDFS-13132-HDFS-7240.002.patch > > > Currently SCM receives heartbeat from the datanodes in the cluster receiving > container reports. Apart from this Ratis leader also receives the heartbeats > from the nodes in a Raft ring. The ratis heartbeats are at a smaller interval > (500 ms) whereas SCM heartbeats are at (30s), it is thereby considered safe > to assume that a datanode is really lost when SCM missed heartbeat from such > a node. > The pipeline recovery will follow the following steps > 1) As noted earlier, SCM will identify a dead DN via the heartbeats. Current > stale interval is (1.5m). Once a stale node has been identified, SCM will > find the list of containers for the pipelines the datanode was part of. > 2) SCM sends close container command to the datanodes, note that at this > time, the Ratis ring has 2 nodes in the ring and consistency can still be > guaranteed by Ratis. > 3) If another node dies before the close container command succeeded, then > ratis cannot guarantee consistency of the data being written/ close > container. The pipeline here will be marked in a inconsistent state. > 4) Closed container will be replicated via the close container replication > protocol. > If the dead datanode comes back, as part of the re-register command, SCM will > ask the Datanode to format all the open containers. > 5) Return the healthy nodes back to the free node pool for the next pipeline > allocation > 6) Read operation to close containers will succeed however read operation to > a open container on a single node cluster will be disallowed. It will only be > allowed under a special flag aka ReadInconsistentData flag. > This jira will introduce the mechanism to identify and handle datanode > failure. > However handling of a) 2 nodes simultaneously and b) Return the nodes to > healthy state c) allow inconsistent data reads and d) purging of open > container on a zombie node will be done as part of separate bugs. -- This message was sent by Atlassian JIRA (v7.6.3#76005) - To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
[jira] [Updated] (HDFS-13132) Ozone: Handle datanode failures in Storage Container Manager
[ https://issues.apache.org/jira/browse/HDFS-13132?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Mukul Kumar Singh updated HDFS-13132: - Attachment: HDFS-13132-HDFS-7240.001.patch > Ozone: Handle datanode failures in Storage Container Manager > > > Key: HDFS-13132 > URL: https://issues.apache.org/jira/browse/HDFS-13132 > Project: Hadoop HDFS > Issue Type: Sub-task > Components: ozone >Affects Versions: HDFS-7240 >Reporter: Mukul Kumar Singh >Assignee: Mukul Kumar Singh >Priority: Major > Fix For: HDFS-7240 > > Attachments: HDFS-13132-HDFS-7240.001.patch > > > Currently SCM receives heartbeat from the datanodes in the cluster receiving > container reports. Apart from this Ratis leader also receives the heartbeats > from the nodes in a Raft ring. The ratis heartbeats are at a smaller interval > (500 ms) whereas SCM heartbeats are at (30s), it is thereby considered safe > to assume that a datanode is really lost when SCM missed heartbeat from such > a node. > The pipeline recovery will follow the following steps > 1) As noted earlier, SCM will identify a dead DN via the heartbeats. Current > stale interval is (1.5m). Once a stale node has been identified, SCM will > find the list of containers for the pipelines the datanode was part of. > 2) SCM sends close container command to the datanodes, note that at this > time, the Ratis ring has 2 nodes in the ring and consistency can still be > guaranteed by Ratis. > 3) If another node dies before the close container command succeeded, then > ratis cannot guarantee consistency of the data being written/ close > container. The pipeline here will be marked in a inconsistent state. > 4) Closed container will be replicated via the close container replication > protocol. > If the dead datanode comes back, as part of the re-register command, SCM will > ask the Datanode to format all the open containers. > 5) Return the healthy nodes back to the free node pool for the next pipeline > allocation > 6) Read operation to close containers will succeed however read operation to > a open container on a single node cluster will be disallowed. It will only be > allowed under a special flag aka ReadInconsistentData flag. > This jira will introduce the mechanism to identify and handle datanode > failure. > However handling of a) 2 nodes simultaneously and b) Return the nodes to > healthy state c) allow inconsistent data reads and d) purging of open > container on a zombie node will be done as part of separate bugs. -- This message was sent by Atlassian JIRA (v7.6.3#76005) - To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
[jira] [Updated] (HDFS-13132) Ozone: Handle datanode failures in Storage Container Manager
[ https://issues.apache.org/jira/browse/HDFS-13132?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Mukul Kumar Singh updated HDFS-13132: - Status: Patch Available (was: Open) > Ozone: Handle datanode failures in Storage Container Manager > > > Key: HDFS-13132 > URL: https://issues.apache.org/jira/browse/HDFS-13132 > Project: Hadoop HDFS > Issue Type: Sub-task > Components: ozone >Affects Versions: HDFS-7240 >Reporter: Mukul Kumar Singh >Assignee: Mukul Kumar Singh >Priority: Major > Fix For: HDFS-7240 > > Attachments: HDFS-13132-HDFS-7240.001.patch > > > Currently SCM receives heartbeat from the datanodes in the cluster receiving > container reports. Apart from this Ratis leader also receives the heartbeats > from the nodes in a Raft ring. The ratis heartbeats are at a smaller interval > (500 ms) whereas SCM heartbeats are at (30s), it is thereby considered safe > to assume that a datanode is really lost when SCM missed heartbeat from such > a node. > The pipeline recovery will follow the following steps > 1) As noted earlier, SCM will identify a dead DN via the heartbeats. Current > stale interval is (1.5m). Once a stale node has been identified, SCM will > find the list of containers for the pipelines the datanode was part of. > 2) SCM sends close container command to the datanodes, note that at this > time, the Ratis ring has 2 nodes in the ring and consistency can still be > guaranteed by Ratis. > 3) If another node dies before the close container command succeeded, then > ratis cannot guarantee consistency of the data being written/ close > container. The pipeline here will be marked in a inconsistent state. > 4) Closed container will be replicated via the close container replication > protocol. > If the dead datanode comes back, as part of the re-register command, SCM will > ask the Datanode to format all the open containers. > 5) Return the healthy nodes back to the free node pool for the next pipeline > allocation > 6) Read operation to close containers will succeed however read operation to > a open container on a single node cluster will be disallowed. It will only be > allowed under a special flag aka ReadInconsistentData flag. > This jira will introduce the mechanism to identify and handle datanode > failure. > However handling of a) 2 nodes simultaneously and b) Return the nodes to > healthy state c) allow inconsistent data reads and d) purging of open > container on a zombie node will be done as part of separate bugs. -- This message was sent by Atlassian JIRA (v7.6.3#76005) - To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
