[ https://issues.apache.org/jira/browse/HDFS-14116?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16710795#comment-16710795 ]
Chao Sun commented on HDFS-14116: --------------------------------- Agree this seems like a separate issue, and I think this problem is not restrict to {{ObserverReadProxyProvider}}. If you change the above command to use {{RequestHedgingProxyProvider}} it will run into the same issue. > 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