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Hive QA commented on HIVE-21469: -------------------------------- | (x) *{color:red}-1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || || || || || {color:brown} Prechecks {color} || | {color:green}+1{color} | {color:green} @author {color} | {color:green} 0m 0s{color} | {color:green} The patch does not contain any @author tags. {color} | || || || || {color:brown} master Compile Tests {color} || | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 8m 52s{color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 1m 25s{color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 0m 44s{color} | {color:green} master passed {color} | | {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue} 4m 27s{color} | {color:blue} ql in master has 2255 extant Findbugs warnings. {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 1m 6s{color} | {color:green} master passed {color} | || || || || {color:brown} Patch Compile Tests {color} || | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 1m 40s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 1m 11s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} javac {color} | {color:green} 1m 11s{color} | {color:green} the patch passed {color} | | {color:red}-1{color} | {color:red} checkstyle {color} | {color:red} 0m 41s{color} | {color:red} ql: The patch generated 1 new + 49 unchanged - 34 fixed = 50 total (was 83) {color} | | {color:green}+1{color} | {color:green} whitespace {color} | {color:green} 0m 0s{color} | {color:green} The patch has no whitespace issues. {color} | | {color:red}-1{color} | {color:red} findbugs {color} | {color:red} 4m 32s{color} | {color:red} ql generated 1 new + 2252 unchanged - 3 fixed = 2253 total (was 2255) {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 1m 5s{color} | {color:green} the patch passed {color} | || || || || {color:brown} Other Tests {color} || | {color:green}+1{color} | {color:green} asflicense {color} | {color:green} 0m 18s{color} | {color:green} The patch does not generate ASF License warnings. {color} | | {color:black}{color} | {color:black} {color} | {color:black} 26m 41s{color} | {color:black} {color} | \\ \\ || Reason || Tests || | FindBugs | module:ql | | | Write to static field org.apache.hadoop.hive.ql.lockmgr.zookeeper.ZooKeeperHiveLockManager.metrics from instance method org.apache.hadoop.hive.ql.lockmgr.zookeeper.ZooKeeperHiveLockManager.setContext(HiveLockManagerCtx) At ZooKeeperHiveLockManager.java:from instance method org.apache.hadoop.hive.ql.lockmgr.zookeeper.ZooKeeperHiveLockManager.setContext(HiveLockManagerCtx) At ZooKeeperHiveLockManager.java:[line 124] | \\ \\ || Subsystem || Report/Notes || | Optional Tests | asflicense javac javadoc findbugs checkstyle compile | | uname | Linux hiveptest-server-upstream 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1+deb8u1 (2016-09-03) x86_64 GNU/Linux | | Build tool | maven | | Personality | /data/hiveptest/working/yetus_PreCommit-HIVE-Build-16626/dev-support/hive-personality.sh | | git revision | master / b953c4e | | Default Java | 1.8.0_111 | | findbugs | v3.0.0 | | checkstyle | http://104.198.109.242/logs//PreCommit-HIVE-Build-16626/yetus/diff-checkstyle-ql.txt | | findbugs | http://104.198.109.242/logs//PreCommit-HIVE-Build-16626/yetus/new-findbugs-ql.html | | modules | C: ql U: ql | | Console output | http://104.198.109.242/logs//PreCommit-HIVE-Build-16626/yetus.txt | | Powered by | Apache Yetus http://yetus.apache.org | This message was automatically generated. > Review of ZooKeeperHiveLockManager > ---------------------------------- > > Key: HIVE-21469 > URL: https://issues.apache.org/jira/browse/HIVE-21469 > Project: Hive > Issue Type: Improvement > Components: Locking > Affects Versions: 4.0.0, 3.2.0 > Reporter: David Mollitor > Assignee: David Mollitor > Priority: Major > Attachments: HIVE-21469.1.patch, HIVE-21469.2.patch, > HIVE-21469.3.patch, HIVE-21469.4.patch > > > A lot of sins in this class to resolve: > {code:java} > @Override > public void setContext(HiveLockManagerCtx ctx) throws LockException { > try { > curatorFramework = CuratorFrameworkSingleton.getInstance(conf); > parent = conf.getVar(HiveConf.ConfVars.HIVE_ZOOKEEPER_NAMESPACE); > try{ > curatorFramework.create().withMode(CreateMode.PERSISTENT).forPath("/" > + parent, new byte[0]); > } catch (Exception e) { > // ignore if the parent already exists > if (!(e instanceof KeeperException) || ((KeeperException)e).code() != > KeeperException.Code.NODEEXISTS) { > LOG.warn("Unexpected ZK exception when creating parent node /" + > parent, e); > } > } > {code} > Every time a new session is created and this {{setContext}} method is called, > it attempts to create the root node. I have seen that, even though the root > node exists, an create node action is written to the ZK logs. Check first if > the node exists before trying to create it. > {code:java} > try { > curatorFramework.delete().forPath(zLock.getPath()); > } catch (InterruptedException ie) { > curatorFramework.delete().forPath(zLock.getPath()); > } > {code} > There has historically been a quite a few bugs regarding leaked locks. The > Driver will signal the session {{Thread}} by performing an interrupt. That > interrupt can happen any time and it can kill a create/delete action within > the ZK framework. We can see one example of workaround for this. If the ZK > action is interrupted, simply do it again. Well, what if it's interrupted > yet again? The lock will be leaked. Also, when the {{InterruptedException}} > is caught in the try block, the thread's interrupted flag is cleared. The > flag is not reset in this code and therefore we lose the fact that this > thread has been interrupted. This flag should be preserved so that other > code paths will know that it's time to exit. > {code:java} > if (tryNum > 1) { > Thread.sleep(sleepTime); > } > unlockPrimitive(hiveLock, parent, curatorFramework); > break; > } catch (Exception e) { > if (tryNum >= numRetriesForUnLock) { > String name = ((ZooKeeperHiveLock)hiveLock).getPath(); > throw new LockException("Node " + name + " can not be deleted after > " + numRetriesForUnLock + " attempts.", > e); > } > } > {code} > ... related... the sleep here may be interrupted, but we still need to delete > the lock (again, for fear of leaking it). This sleep should be > uninterruptible. If we need to get the lock deleted, and there's a problem, > interrupting the sleep will cause the code to eventually exit and locks will > be leaked. > It also requires a bunch more TLC. -- This message was sent by Atlassian JIRA (v7.6.3#76005)