Hi, I'm running into similar problems, have you find a way to solve/workaround the issue?
Thanks. dcheckoway wrote: > > Hello, > > I have an app that needs to make concurrent HTTP requests to a web service > using persistent (keepalive) connections. I'm using > ThreadSafeClientConnManager. I ran into a performance bottleneck, and I > believe I've pinpointed the issue... > > Affects Version(s): HttpCore 4.1.3, HttpClient 4.1.2 > > I construct my connection manager and client like this: > > connMgr = new > ThreadSafeClientConnManager(SchemeRegistryFactory.createDefault(), -1, > TimeUnit.MILLISECONDS); > connMgr.setMaxTotal(400); > connMgr.setDefaultMaxPerRoute(400); > > httpClient = new DefaultHttpClient(connMgr); > > Note that this app only talks to a single URI on a single server -- thus > defaultMaxPerRoute == maxTotal, which I think is correct...please let me > know if that's bad! > > Anyway, my app has a pool of 400 threads and generally performs quite > well. But when all 400 threads need a connection concurrently, > performance > suffers. I've narrowed it down to contention caused by blocking calls in > the connection manager. For example...a thread dump shows... > > About half my threads are "stuck" (well, not stuck, but slow & waiting) > here: > > "catalina-exec-347" daemon prio=10 tid=0x00007f3a54065000 nid=0x6b73 > waiting on condition [0x00007f3a29b9a000] > java.lang.Thread.State: WAITING (parking) > at sun.misc.Unsafe.park(Native Method) > - parking to wait for <0x00000006147c8318> (a > java.util.concurrent.locks.ReentrantLock$NonfairSync) > at java.util.concurrent.locks.LockSupport.park(LockSupport.java:158) > at > java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:811) > at > java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:842) > at > java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1178) > at > java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:186) > at > java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:262) > at > org.apache.http.impl.conn.tsccm.ConnPoolByRoute.freeEntry(ConnPoolByRoute.java:438) > at > org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager.releaseConnection(ThreadSafeClientConnManager.java:276) > - locked <0x000000062048ebc8> (a > org.apache.http.impl.conn.tsccm.BasicPooledConnAdapter) > at > org.apache.http.impl.conn.AbstractClientConnAdapter.releaseConnection(AbstractClientConnAdapter.java:308) > - locked <0x000000062048ebc8> (a > org.apache.http.impl.conn.tsccm.BasicPooledConnAdapter) > at > org.apache.http.conn.BasicManagedEntity.releaseManagedConnection(BasicManagedEntity.java:181) > at > org.apache.http.conn.BasicManagedEntity.eofDetected(BasicManagedEntity.java:142) > at > org.apache.http.conn.EofSensorInputStream.checkEOF(EofSensorInputStream.java:211) > at > org.apache.http.conn.EofSensorInputStream.read(EofSensorInputStream.java:139) > ... > > While the other half are "stuck" here: > > "catalina-exec-346" daemon prio=10 tid=0x00007f3a4c05d000 nid=0x6b72 > waiting on condition [0x00007f3a29c9b000] > java.lang.Thread.State: WAITING (parking) > at sun.misc.Unsafe.park(Native Method) > - parking to wait for <0x00000006147c8318> (a > java.util.concurrent.locks.ReentrantLock$NonfairSync) > at java.util.concurrent.locks.LockSupport.park(LockSupport.java:158) > at > java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:811) > at > java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:842) > at > java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1178) > at > java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:186) > at > java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:262) > at > org.apache.http.impl.conn.tsccm.ConnPoolByRoute.getEntryBlocking(ConnPoolByRoute.java:337) > at > org.apache.http.impl.conn.tsccm.ConnPoolByRoute$1.getPoolEntry(ConnPoolByRoute.java:300) > at > org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager$1.getConnection(ThreadSafeClientConnManager.java:224) > at > org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:401) > at > org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:820) > at > org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:941) > ... > > It's not a deadlock per se. It's just a bottleneck, and it is causing > very > high latency in my app. Below a certain threshold, i.e. when not all 400 > threads need a connection concurrently, things are fine. But when all 400 > need a connection at once, that's when it gets painful. > > I'm wondering if it might be feasible to switch to using non-blocking > calls > for this, i.e. with ConcurrentHashMap and/or ConcurrentLinkedQueue, or > something of that nature? I haven't dived into the source code yet, so > don't slap me too hard if that suggestion was way out of line. :-) > > Do you have any suggestions, in terms of ways I might be able to work > around this bottleneck otherwise? > > Thanks! > > Dan Checkoway > > -- View this message in context: http://old.nabble.com/Possibility-of-using-non-blocking-calls-for-connection-pools--tp33093916p33182743.html Sent from the HttpClient-User mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe, e-mail: httpclient-users-unsubscr...@hc.apache.org For additional commands, e-mail: httpclient-users-h...@hc.apache.org
