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Tom DeVoe commented on KAFKA-4477: ---------------------------------- An additional comment - after we restart the node with this issue, there are a large number of Unclean Leader Elections (presumably all topic-partitions that the bad node was the leader of) and so we may lose a bit of data. > Node reduces its ISR to itself, and doesn't recover. Other nodes do not take > leadership, cluster remains sick until node is restarted. > -------------------------------------------------------------------------------------------------------------------------------------- > > Key: KAFKA-4477 > URL: https://issues.apache.org/jira/browse/KAFKA-4477 > Project: Kafka > Issue Type: Bug > Components: core > Affects Versions: 0.10.1.0 > Environment: RHEL7 > java version "1.8.0_66" > Java(TM) SE Runtime Environment (build 1.8.0_66-b17) > Java HotSpot(TM) 64-Bit Server VM (build 25.66-b17, mixed mode) > Reporter: Michael Andre Pearce (IG) > Priority: Critical > Labels: reliability > Attachments: kafka.jstack > > > We have encountered a critical issue that has re-occured in different > physical environments. We haven't worked out what is going on. We do though > have a nasty work around to keep service alive. > We do have not had this issue on clusters still running 0.9.01. > We have noticed a node randomly shrinking for the partitions it owns the > ISR's down to itself, moments later we see other nodes having disconnects, > followed by finally app issues, where producing to these partitions is > blocked. > It seems only by restarting the kafka instance java process resolves the > issues. > We have had this occur multiple times and from all network and machine > monitoring the machine never left the network, or had any other glitches. > Below are seen logs from the issue. > Node 7: > [2016-12-01 07:01:28,112] INFO Partition > [com_ig_trade_v1_position_event--demo--compacted,10] on broker 7: Shrinking > ISR for partition [com_ig_trade_v1_position_event--demo--compacted,10] from > 1,2,7 to 7 (kafka.cluster.Partition) > All other nodes: > [2016-12-01 07:01:38,172] WARN [ReplicaFetcherThread-0-7], Error in fetch > kafka.server.ReplicaFetcherThread$FetchRequest@5aae6d42 > (kafka.server.ReplicaFetcherThread) > java.io.IOException: Connection to 7 was disconnected before the response was > read > All clients: > java.util.concurrent.ExecutionException: > org.apache.kafka.common.errors.NetworkException: The server disconnected > before a response was received. > After this occurs, we then suddenly see on the sick machine an increasing > amount of close_waits and file descriptors. > As a work around to keep service we are currently putting in an automated > process that tails and regex's for: and where new_partitions hit just itself > we restart the node. > "\[(?P<time>.+)\] INFO Partition \[.*\] on broker .* Shrinking ISR for > partition \[.*\] from (?P<old_partitions>.+) to (?P<new_partitions>.+) > \(kafka.cluster.Partition\)" -- This message was sent by Atlassian JIRA (v6.3.4#6332)