问题
We have a use case as below
1-) Start 2 ignite instance as data nodes and insert data into the cache.
2-) Create a queue and register a remote listener by using remoteListen as below
//Queue creation
CollectionConfiguration colCfg = new CollectionConfiguration();
colCfg.setCacheMode(PARTITIONED);
IgniteQueue<BinaryObject> queue = Ignition.ignite().queue(queueName, 0, colCfg);
//Remote Listener Closure
IgnitePredicate<CacheEvent> rmtLsnr = new IgnitePredicate<CacheEvent>() {
@Override public boolean apply(CacheEvent evt) {
System.out.println("Cache event [name=" + evt.name() + ", key=" + evt.key() + ']');
Ignite ignite = Ignition.ignite();
IgniteQueue<String> queue = ignite.queue(queueName, 0, null);
String key = evt.key();
BinaryObject profile = (BinaryObject) evt.newValue();
System.out.println("Received event [evt=" + evt.name() + ", key=" + evt.key() +
", oldVal=" + evt.oldValue().toString() + ", newVal=" + evt.newValue().toString());
if (profile.<Double>field("usage") > start && profile.<Double>field("usage") < end
&& ignite.affinity("profileCache").isPrimary(ignite.cluster().localNode(), key)){
queue.add(profile.field("number"));
}
return false;
}
};
Ignition.ignite().events(ignite.cluster().forCacheNodes("profileCache")).remoteListen(1,1l,false,null, rmtLsnr,
EVT_CACHE_OBJECT_PUT, EVT_CACHE_OBJECT_REMOVED);
3-)Do some updates in the cache instances as below to get updates into the remotelistener.
void updateAnyProfile(Double newUsage){
SqlQuery qry = new SqlQuery(Profile.class,"select * from Profile where usage < 30 limit 10");
List<CacheEntryImpl<String, profile>> res = profileCache.query(qry).getAll();
Profile profile = res.iterator().next().getValue();
profile.setUsage(newUsage);
profileCache.put(profile.getCtn(), profile);
profile.setUsage(newUsage+1);
profileCache.put(profile.getCtn(), profile);
}
4-) Take the elements from the queue.
public void readFromQueue (String queueName) {
// Initialize new FIFO queue.
IgniteQueue<String> queue = Ignition.ignite().queue(queueName, 0, null);
while (true) {
String profile = queue.take();
System.out.println("Profile from queue: " + profile.toString());
}
}
Step 2,3,4 are run from different JVM instances with client node TRUE. The problem is application hangs to do any operation after doing above scenario. Could you please help us? We would really appreciate if you could tell us what we are doing wrong?
Below is the thread dump of the hanging datanode and same datanode hangs at below code
IgniteQueue<String> queue = ignite.queue(queueName, 0, null);
Sometimes you can update the records successfully and after next update it starts hanging or can not even do put operation in the cache.
"sys-stripe-5-#6%null%" #25 prio=5 os_prio=31 tid=0x00007fd88d031800 nid=0x14c07 waiting on condition [0x00007000036e7000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:304)
at org.apache.ignite.internal.util.future.GridFutureAdapter.get0(GridFutureAdapter.java:176)
at org.apache.ignite.internal.util.future.GridFutureAdapter.get(GridFutureAdapter.java:139)
at org.apache.ignite.internal.processors.cache.GridCacheAdapter.get0(GridCacheAdapter.java:4482)
at org.apache.ignite.internal.processors.cache.GridCacheAdapter.get(GridCacheAdapter.java:4463)
at org.apache.ignite.internal.processors.cache.GridCacheAdapter.get(GridCacheAdapter.java:1405)
at org.apache.ignite.internal.processors.cache.datastructures.CacheDataStructuresManager.queue0(CacheDataStructuresManager.java:270)
at org.apache.ignite.internal.processors.cache.datastructures.CacheDataStructuresManager.queue(CacheDataStructuresManager.java:231)
at org.apache.ignite.internal.processors.datastructures.DataStructuresProcessor$12.applyx(DataStructuresProcessor.java:952)
at org.apache.ignite.internal.processors.datastructures.DataStructuresProcessor$12.applyx(DataStructuresProcessor.java:950)
at org.apache.ignite.internal.processors.datastructures.DataStructuresProcessor.getCollection(DataStructuresProcessor.java:1078)
at org.apache.ignite.internal.processors.datastructures.DataStructuresProcessor.queue(DataStructuresProcessor.java:950)
at org.apache.ignite.internal.IgniteKernal.queue(IgniteKernal.java:3560)
at com.ignite.trial.roaming.ProfileService$4.apply(ProfileService.java:303)
at com.ignite.trial.roaming.ProfileService$4.apply(ProfileService.java:297)
at org.apache.ignite.internal.GridEventConsumeHandler$2.onEvent(GridEventConsumeHandler.java:170)
at org.apache.ignite.internal.managers.eventstorage.GridEventStorageManager$LocalListenerWrapper.onEvent(GridEventStorageManager.java:1311)
at org.apache.ignite.internal.managers.eventstorage.GridEventStorageManager.notifyListeners(GridEventStorageManager.java:892)
at org.apache.ignite.internal.managers.eventstorage.GridEventStorageManager.record0(GridEventStorageManager.java:340)
at org.apache.ignite.internal.managers.eventstorage.GridEventStorageManager.record(GridEventStorageManager.java:297)
at org.apache.ignite.internal.processors.cache.GridCacheEventManager.addEvent(GridCacheEventManager.java:297)
at org.apache.ignite.internal.processors.cache.GridCacheMapEntry.innerUpdate(GridCacheMapEntry.java:1806)
- locked <0x00000007b6d01f10> (a org.apache.ignite.internal.processors.cache.distributed.dht.atomic.GridDhtAtomicCacheEntry)
at org.apache.ignite.internal.processors.cache.distributed.dht.atomic.GridDhtAtomicCache.updateSingle(GridDhtAtomicCache.java:2386)
at org.apache.ignite.internal.processors.cache.distributed.dht.atomic.GridDhtAtomicCache.updateAllAsyncInternal0(GridDhtAtomicCache.java:1792)
at org.apache.ignite.internal.processors.cache.distributed.dht.atomic.GridDhtAtomicCache.updateAllAsyncInternal(GridDhtAtomicCache.java:1630)
at org.apache.ignite.internal.processors.cache.distributed.dht.atomic.GridDhtAtomicCache.processNearAtomicUpdateRequest(GridDhtAtomicCache.java:3016)
at org.apache.ignite.internal.processors.cache.distributed.dht.atomic.GridDhtAtomicCache.access$400(GridDhtAtomicCache.java:127)
at org.apache.ignite.internal.processors.cache.distributed.dht.atomic.GridDhtAtomicCache$6.apply(GridDhtAtomicCache.java:282)
at org.apache.ignite.internal.processors.cache.distributed.dht.atomic.GridDhtAtomicCache$6.apply(GridDhtAtomicCache.java:277)
at org.apache.ignite.internal.processors.cache.GridCacheIoManager.processMessage(GridCacheIoManager.java:863)
at org.apache.ignite.internal.processors.cache.GridCacheIoManager.onMessage0(GridCacheIoManager.java:386)
at org.apache.ignite.internal.processors.cache.GridCacheIoManager.handleMessage(GridCacheIoManager.java:308)
at org.apache.ignite.internal.processors.cache.GridCacheIoManager.access$000(GridCacheIoManager.java:100)
at org.apache.ignite.internal.processors.cache.GridCacheIoManager$1.onMessage(GridCacheIoManager.java:253)
at org.apache.ignite.internal.managers.communication.GridIoManager.invokeListener(GridIoManager.java:1257)
at org.apache.ignite.internal.managers.communication.GridIoManager.processRegularMessage0(GridIoManager.java:885)
at org.apache.ignite.internal.managers.communication.GridIoManager.access$2100(GridIoManager.java:114)
at org.apache.ignite.internal.managers.communication.GridIoManager$7.run(GridIoManager.java:802)
at org.apache.ignite.internal.util.StripedExecutor$Stripe.run(StripedExecutor.java:483)
at java.lang.Thread.run(Thread.java:748)
回答1:
It's not allowed to invoke ignite.queue and ignite.affinity methods in EventListener, because it may lead to deadlock.
All cache operations, including EventListeners are executed in system pool, so it's not recommended to invoke inside EventListener operations, that uses system pool too.
You could read more here at "Closures Execution and Thread Pools": https://apacheignite.readme.io/docs/async-support#section-listeners-and-chaining-futures
And here https://apacheignite.readme.io/docs/thread-pools#section-system-pool
来源：https://stackoverflow.com/questions/43891757/closures-stuck-in-2-0-when-try-to-add-an-element-into-the-queue