[jira] [Assigned] (NIFI-5663) FlowFile load balancing keeps re-partitioning

["Mark Payne (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/NIFI-5663?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Mark Payne reassigned NIFI-5663:
--------------------------------

    Assignee: Mark Payne

> FlowFile load balancing keeps re-partitioning
> ---------------------------------------------
>
>                 Key: NIFI-5663
>                 URL: https://issues.apache.org/jira/browse/NIFI-5663
>             Project: Apache NiFi
>          Issue Type: Bug
>          Components: Core Framework
>    Affects Versions: 1.8.0
>            Reporter: Koji Kawamura
>            Assignee: Mark Payne
>            Priority: Critical
>
> Scenario
>  # Start a brand-new cluster with only 1 node (nifi0). Using existing multi-node clusters don't reproduce the issue.
>  # Create GenerateFlowFile -> LogAttribute
>  # Then set 'Partition by attribute' LB strategy at the connection
>  # Add 2nd node, nifi1
>  # Generate some FlowFiles. Then load-balance activity never finishes.
> With a 2-node cluster, for some reason, each node ended up having different queuePartitions order at SocketLoadBalancedFlowFileQueue. By adding debug logs, I found each node has followings:
>  * nifi0
>  ** queuePartitions[0} = RemoteQueuePartition[queueId=14ac9634-0166-1000-ffff-ffffd9ae7f4b, nodeId=nifi1.example.com:8080]
>  ** queuePartitions[1} = SwappablePriorityQueueLocalPartition[queueId=14ac9634-0166-1000-ffff-ffffd9ae7f4b]
>  * nifi1
>  ** queuePartitions[0} = RemoteQueuePartition[queueId=14ac9634-0166-1000-ffff-ffffd9ae7f4b, nodeId=nifi0.example.com:8080]
>  ** queuePartitions[1} = SwappablePriorityQueueLocalPartition[queueId=14ac9634-0166-1000-ffff-ffffd9ae7f4b]
> Because of this, 'Partition by attribute' LB strategy keeps re-partitioning received FlowFiles between each other in case the calculated attribute value hash points to queuePartitions[0]. Following log is written endlessly:
> {code:java}
> 2018-10-05 07:09:32,372 DEBUG [Load Balance Server Thread-3] o.a.n.c.q.c.SocketLoadBalancedFlowFileQueue Received the following FlowFiles from Peer: ...offset=7452, length=180],offset=162,name=10653317458635,size=18]]. Will re-partition FlowFiles to ensure proper balancing across the cluster.
> {code}
> SocketLoadBalancedFlowFileQueue maintains queuePartitions by listening to cluster topology change using ClusterTopologyEventListener. SocketLoadBalancedFlowFileQueueClusterEventListener.onNodeAdded debug log shows the array was empty when the 2nd node (nifi1) is added:
> {code:java}
> ClusterEventListener.onNodeAdded. 2018-10-05 07:06:42,883 DEBUG [Process Cluster Protocol Request-10] o.a.n.c.q.c.SocketLoadBalancedFlowFileQueue Node Identifier nifi1.example.com:8080 added to cluster. Node ID's changing from [] to [nifi1.example.com:8080]
> {code}



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)