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Mike Drob commented on CURATOR-167: ----------------------------------- [~cammckenzie] - Can you make sure that the PR is current and then merge what we can fix? [~randgalt] - What is the JIRA for the fix using the clear watchers API? > All registered watchers should be cleared on close > -------------------------------------------------- > > Key: CURATOR-167 > URL: https://issues.apache.org/jira/browse/CURATOR-167 > Project: Apache Curator > Issue Type: Bug > Components: Client > Affects Versions: 2.6.0 > Environment: Linux 3.13.0-37-generic #64~precise1-Ubuntu SMP Wed Sep > 24 21:39:43 UTC 2014 i686 i686 i386 GNU/Linux > java version "1.7.0_13" > Java(TM) SE Runtime Environment (build 1.7.0_13-b20) > Java HotSpot(TM) Server VM (build 23.7-b01, mixed mode) > Reporter: Craig McNally > Assignee: Cameron McKenzie > Priority: Critical > Labels: heap, memory-leak, node-cache > Fix For: 2.9.0 > > Attachments: heap.png, yourKit_NodeCacheMemoryLeakTest.png, > yourKit_NodeCache_ConnectionListenerLeak.png > > > There's a memory leak in NodeCache. I was able to reliably reproduce the > problem using a very simple test that performs the following: > 1) Creates a CuratorFramework instance and starts it. > 2) in a loop: Creates a NodeCache and starts it, then closes it. > Eventually you get a java.lang.OutOfMemoryError: Java heap space. This > happens regardless of the heap size, though it happens much faster with a > small heap. > Upon furher investigation w/ a profiler, I can see that each NodeCache is > being referenced by the NamespaceWatcherMap. > Here's the test code: > {code:title=NodeCacheLeakTest.java|borderStyle=solid} > import java.util.Date; > import org.apache.curator.framework.CuratorFramework; > import org.apache.curator.framework.CuratorFrameworkFactory; > import org.apache.curator.framework.recipes.cache.NodeCache; > import org.apache.curator.retry.ExponentialBackoffRetry; > public class NodeCacheLeakTest { > public static void main(String[] args) throws Exception { > String zkConnect; > if (args.length > 0 && args[0] != null) > zkConnect = args[0]; > else > zkConnect = "localhost:2181/test"; > CuratorFramework curator = > CuratorFrameworkFactory.newClient(zkConnect, > new ExponentialBackoffRetry(500, 10)); > curator.start(); > int count = 0; > while (true) { > String nodePath = "/foo/node-" + (count); > NodeCache cache = new NodeCache(curator, nodePath); > cache.start(true); > cache.close(); > count++; > if (count % 1000 == 0) > System.out.println(new Date() + " Started and > Closed " + count > + " NodeCache instances"); > } > } > } > {code} > And here's the output/OOM Error when using (-Xms10m -Xmx10m -XX:+UseG1GC): > {noformat} > log4j:WARN No appenders could be found for logger > (org.apache.curator.framework.imps.CuratorFrameworkImpl). > log4j:WARN Please initialize the log4j system properly. > log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more > info. > Tue Nov 18 15:59:12 GMT+00:00 2014 Started and Closed 1000 NodeCache instances > Tue Nov 18 15:59:16 GMT+00:00 2014 Started and Closed 2000 NodeCache instances > Tue Nov 18 15:59:20 GMT+00:00 2014 Started and Closed 3000 NodeCache instances > Tue Nov 18 15:59:23 GMT+00:00 2014 Started and Closed 4000 NodeCache instances > Tue Nov 18 15:59:27 GMT+00:00 2014 Started and Closed 5000 NodeCache instances > Tue Nov 18 15:59:31 GMT+00:00 2014 Started and Closed 6000 NodeCache instances > Tue Nov 18 15:59:36 GMT+00:00 2014 Started and Closed 7000 NodeCache instances > Tue Nov 18 15:59:40 GMT+00:00 2014 Started and Closed 8000 NodeCache instances > Tue Nov 18 15:59:45 GMT+00:00 2014 Started and Closed 9000 NodeCache instances > Tue Nov 18 15:59:49 GMT+00:00 2014 Started and Closed 10000 NodeCache > instances > Tue Nov 18 16:00:01 GMT+00:00 2014 Started and Closed 11000 NodeCache > instances > java.lang.OutOfMemoryError: Java heap space > at java.io.BufferedWriter.<init>(BufferedWriter.java:105) > at java.io.BufferedWriter.<init>(BufferedWriter.java:88) > at java.io.PrintStream.<init>(PrintStream.java:112) > at java.io.PrintStream.<init>(PrintStream.java:175) > at org.apache.jute.CsvOutputArchive.<init>(CsvOutputArchive.java:57) > at > org.apache.zookeeper.proto.RequestHeader.toString(RequestHeader.java:62) > at java.lang.String.valueOf(String.java:2854) > at java.lang.StringBuilder.append(StringBuilder.java:128) > at org.apache.zookeeper.ClientCnxn$Packet.toString(ClientCnxn.java:308) > at java.lang.String.valueOf(String.java:2854) > at java.lang.StringBuilder.append(StringBuilder.java:128) > at > org.apache.zookeeper.ClientCnxn$SendThread.readResponse(ClientCnxn.java:815) > at > org.apache.zookeeper.ClientCnxnSocketNIO.doIO(ClientCnxnSocketNIO.java:94) > at > org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:355) > at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1068) > java.lang.OutOfMemoryError: Java heap space > at java.io.BufferedWriter.<init>(BufferedWriter.java:105) > at java.io.BufferedWriter.<init>(BufferedWriter.java:88) > at java.io.PrintStream.<init>(PrintStream.java:112) > at java.io.PrintStream.<init>(PrintStream.java:175) > at org.apache.jute.CsvOutputArchive.<init>(CsvOutputArchive.java:57) > at > org.apache.zookeeper.proto.RequestHeader.toString(RequestHeader.java:62) > at java.lang.String.valueOf(String.java:2854) > at java.lang.StringBuilder.append(StringBuilder.java:128) > at org.apache.zookeeper.ClientCnxn$Packet.toString(ClientCnxn.java:308) > at java.lang.String.valueOf(String.java:2854) > at java.lang.StringBuilder.append(StringBuilder.java:128) > at > org.apache.zookeeper.ClientCnxn$SendThread.readResponse(ClientCnxn.java:815) > at > org.apache.zookeeper.ClientCnxnSocketNIO.doIO(ClientCnxnSocketNIO.java:94) > at > org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:355) > at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1068) > java.lang.OutOfMemoryError: Java heap space > at java.io.BufferedWriter.<init>(BufferedWriter.java:105) > at java.io.BufferedWriter.<init>(BufferedWriter.java:88) > at java.io.PrintStream.<init>(PrintStream.java:112) > at java.io.PrintStream.<init>(PrintStream.java:175) > at org.apache.jute.CsvOutputArchive.<init>(CsvOutputArchive.java:57) > at > org.apache.zookeeper.proto.RequestHeader.toString(RequestHeader.java:62) > at java.lang.String.valueOf(String.java:2854) > at java.lang.StringBuilder.append(StringBuilder.java:128) > at org.apache.zookeeper.ClientCnxn$Packet.toString(ClientCnxn.java:308) > at java.lang.String.valueOf(String.java:2854) > at java.lang.StringBuilder.append(StringBuilder.java:128) > at > org.apache.zookeeper.ClientCnxn$SendThread.readResponse(ClientCnxn.java:815) > at > org.apache.zookeeper.ClientCnxnSocketNIO.doIO(ClientCnxnSocketNIO.java:94) > at > org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:355) > at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1068) > java.lang.OutOfMemoryError: Java heap space > at java.io.BufferedWriter.<init>(BufferedWriter.java:105) > at java.io.BufferedWriter.<init>(BufferedWriter.java:88) > at java.io.PrintStream.<init>(PrintStream.java:112) > at java.io.PrintStream.<init>(PrintStream.java:175) > at org.apache.jute.CsvOutputArchive.<init>(CsvOutputArchive.java:57) > at > org.apache.zookeeper.proto.RequestHeader.toString(RequestHeader.java:62) > at java.lang.String.valueOf(String.java:2854) > at java.lang.StringBuilder.append(StringBuilder.java:128) > at org.apache.zookeeper.ClientCnxn$Packet.toString(ClientCnxn.java:308) > at java.lang.String.valueOf(String.java:2854) > at java.lang.StringBuilder.append(StringBuilder.java:128) > at > org.apache.zookeeper.ClientCnxn$SendThread.readResponse(ClientCnxn.java:815) > at > org.apache.zookeeper.ClientCnxnSocketNIO.doIO(ClientCnxnSocketNIO.java:94) > at > org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:355) > at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1068) > Exception: java.lang.OutOfMemoryError thrown from the > UncaughtExceptionHandler in thread "main" > {noformat} > Additional Notes: > * When I don't specify the G1 collector I still get OutOfMemoryErrors, only > the cause is "GC overhead limit exceeded". > {noformat}java.lang.OutOfMemoryError: GC overhead limit exceeded > at java.io.BufferedWriter.<init>(BufferedWriter.java:105) > at java.io.BufferedWriter.<init>(BufferedWriter.java:88) > at java.io.PrintStream.<init>(PrintStream.java:112) > at java.io.PrintStream.<init>(PrintStream.java:175) > at org.apache.jute.CsvOutputArchive.<init>(CsvOutputArchive.java:57) > at > org.apache.zookeeper.proto.GetDataRequest.toString(GetDataRequest.java:62) > at java.lang.String.valueOf(String.java:2854) > at java.lang.StringBuilder.append(StringBuilder.java:128) > at org.apache.zookeeper.ClientCnxn$Packet.toString(ClientCnxn.java:310) > at java.lang.String.valueOf(String.java:2854) > at java.lang.StringBuilder.append(StringBuilder.java:128) > at > org.apache.zookeeper.ClientCnxn$SendThread.readResponse(ClientCnxn.java:815) > at > org.apache.zookeeper.ClientCnxnSocketNIO.doIO(ClientCnxnSocketNIO.java:94) > at > org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:355) > at > org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1068){noformat} > * This has been around for a while as I first noticed it with v1.3.3. I > upgraded to v2.6.0 and re-ran the test, but as you can see this still appears > to be an issue. > * I ran this test on a x86_64 Ubuntu 10.043 system and observed the same > behavior -- This message was sent by Atlassian JIRA (v6.3.4#6332)