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Yongjun Zhang commented on HDFS-13115: -------------------------------------- Hi [~szetszwo], Sorry I posted my previous comment in wrong Jira here. Would you please move your comment above to HDFS-12051? Thanks. > In getNumUnderConstructionBlocks(), ignore the inodeIds for which the inodes > have been deleted > ----------------------------------------------------------------------------------------------- > > Key: HDFS-13115 > URL: https://issues.apache.org/jira/browse/HDFS-13115 > Project: Hadoop HDFS > Issue Type: Bug > Reporter: Yongjun Zhang > Assignee: Yongjun Zhang > Priority: Major > Attachments: HDFS-13115.001.patch, HDFS-13115.002.patch > > > In LeaseManager, > {code} > private synchronized INode[] getINodesWithLease() { > List<INode> inodes = new ArrayList<>(leasesById.size()); > INode currentINode; > for (long inodeId : leasesById.keySet()) { > currentINode = fsnamesystem.getFSDirectory().getInode(inodeId); > // A file with an active lease could get deleted, or its > // parent directories could get recursively deleted. > if (currentINode != null && > currentINode.isFile() && > !fsnamesystem.isFileDeleted(currentINode.asFile())) { > inodes.add(currentINode); > } > } > return inodes.toArray(new INode[0]); > } > {code} > we can see that given an {{inodeId}}, > {{fsnamesystem.getFSDirectory().getInode(inodeId)}} could return NULL . The > reason is explained in the comment. > HDFS-12985 RCAed a case and solved that case, we saw that it fixes some > cases, but we are still seeing NullPointerException from FSnamesystem > {code} > public long getCompleteBlocksTotal() { > // Calculate number of blocks under construction > long numUCBlocks = 0; > readLock(); > try { > numUCBlocks = leaseManager.getNumUnderConstructionBlocks(); <=== here > return getBlocksTotal() - numUCBlocks; > } finally { > readUnlock(); > } > } > {code} > The exception happens when the inode is removed for the given inodeid, see > LeaseManager code below: > {code} > synchronized long getNumUnderConstructionBlocks() { > assert this.fsnamesystem.hasReadLock() : "The FSNamesystem read lock > wasn't" > + "acquired before counting under construction blocks"; > long numUCBlocks = 0; > for (Long id : getINodeIdWithLeases()) { > final INodeFile cons = > fsnamesystem.getFSDirectory().getInode(id).asFile(); <=== here > Preconditions.checkState(cons.isUnderConstruction()); > BlockInfo[] blocks = cons.getBlocks(); > if(blocks == null) > continue; > for(BlockInfo b : blocks) { > if(!b.isComplete()) > numUCBlocks++; > } > } > LOG.info("Number of blocks under construction: " + numUCBlocks); > return numUCBlocks; > } > {code} > Create this jira to add a check whether the inode is removed, as a safeguard, > to avoid the NullPointerException. > Looks that after the inodeid is returned by {{getINodeIdWithLeases()}}, it > got deleted from FSDirectory map. > Ideally we should find out who deleted it, like in HDFS-12985. > But it seems reasonable to me to have a safeguard here, like other code that > calls to {{fsnamesystem.getFSDirectory().getInode(id)}} in the code base. -- 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