[ https://issues.apache.org/jira/browse/HDFS-12487?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Anu Engineer updated HDFS-12487: -------------------------------- Labels: (was: patch) > FsDatasetSpi.isValidBlock() lacks null pointer check inside and neither do > the callers > -------------------------------------------------------------------------------------- > > Key: HDFS-12487 > URL: https://issues.apache.org/jira/browse/HDFS-12487 > Project: Hadoop HDFS > Issue Type: Bug > Components: balancer & mover, diskbalancer > Affects Versions: 3.0.0 > Environment: CentOS 6.8 x64 > CPU:4 core > Memory:16GB > Hadoop: Release 3.0.0-alpha4 > Reporter: liumi > Fix For: 3.0.0 > > Original Estimate: 0h > Remaining Estimate: 0h > > BlockIteratorImpl.nextBlock() will look for the blocks in the source volume, > if there are no blocks any more, it will return null up to > DiskBalancer.getBlockToCopy(). However, the DiskBalancer.getBlockToCopy() > will check whether it's a valid block. > When I look into the FsDatasetSpi.isValidBlock(), I find that it doesn't > check the null pointer! In fact, we firstly need to check whether it's null > or not, or exception will occur. > This bug is hard to find, because the DiskBalancer hardly copy all the data > of one volume to others. Even if some times we may copy all the data of one > volume to other volumes, when the bug occurs, the copy process has already > done. > However, when we try to copy all the data of two or more volumes to other > volumes in more than one step, the thread will be shut down, which is caused > by the bug above. > The bug can fixed by two ways: > 1)Before the call of FsDatasetSpi.isValidBlock(), we check the null pointer > 2)Check the null pointer inside the implementation of > FsDatasetSpi.isValidBlock() -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org