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Chen Liang commented on HDFS-14116: ----------------------------------- Thanks for the finding [~shv], seems this error is different though. Because this is triggering a different code path, causing a different class casting. For fsck to work, as a current workaround, we can override configs to use configured proxy provider in the fsck command. For example if we have fs.defaultFS=ns1, we can call fsck as {code} hdfs fsck -Ddfs.client.failover.proxy.provider.ns1= \ org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider hdfs://ns1/<path> {code} Still need to fix this though. > Fix a potential class cast error in ObserverReadProxyProvider > ------------------------------------------------------------- > > Key: HDFS-14116 > URL: https://issues.apache.org/jira/browse/HDFS-14116 > Project: Hadoop HDFS > Issue Type: Sub-task > Components: hdfs-client > Reporter: Chen Liang > Assignee: Chao Sun > Priority: Major > > Currently in {{ObserverReadProxyProvider}} constructor there is this line > {code} > ((ClientHAProxyFactory<T>) factory).setAlignmentContext(alignmentContext); > {code} > This could potentially cause failure, because it is possible that factory can > not be casted here. Specifically, > {{NameNodeProxiesClient.createFailoverProxyProvider}} is where the > constructor will be called, and there are two paths that could call into this: > (1).{{NameNodeProxies.createProxy}} > (2).{{NameNodeProxiesClient.createFailoverProxyProvider}} > (2) works fine because it always uses {{ClientHAProxyFactory}} but (1) uses > {{NameNodeHAProxyFactory}} which can not be casted to > {{ClientHAProxyFactory}}, this happens when, for example, running > NNThroughputBenmarck. To fix this we can at least: > 1. introduce setAlignmentContext to HAProxyFactory which is the parent of > both ClientHAProxyFactory and NameNodeHAProxyFactory OR > 2. only setAlignmentContext when it is ClientHAProxyFactory by, say, having a > if check with reflection. > Depending on whether it make sense to have alignment context for the case (1) > calling code paths. -- 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