Aerospike Java 异步客户端阻塞

Question

我正在尝试使用异步 java 客户端进行异步读取。我指的是中提到的示例 http://www.aerospike.com/docs/client/java/usage/async

我在下面使用 get 进行阅读 get(BatchPolicy 策略，RecordArrayListener 监听器，Key[] 键)

这适用于很少的请求，但是在发出近约 50000 个请求后，线程进入无限期等待状态。下面是其中一个线程的堆栈跟踪。

"pool-11-thread-1" - Thread t@56
   java.lang.Thread.State: WAITING
    at sun.misc.Unsafe.park(Native Method)
    - parking to wait for <737890e3> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
    at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
    at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
    at java.util.concurrent.ArrayBlockingQueue.take(ArrayBlockingQueue.java:403)
    at com.aerospike.client.async.AsyncCluster$BlockBufferQueue.getByteBuffer(AsyncCluster.java:114)
    at com.aerospike.client.async.AsyncCluster.getByteBuffer(AsyncCluster.java:68)
    at com.aerospike.client.async.AsyncCommand.execute(AsyncCommand.java:59)
    at com.aerospike.client.async.AsyncMul    tiExecutor.execute(AsyncMultiExecutor.java:36)
    at com.aerospike.client.async.AsyncBatch$GetArrayExecutor.<init>(AsyncBatch.java:249)
    at com.aerospike.client.async.AsyncClient.get(AsyncClient.java:568)

谁能建议我为什么会发生这种情况或如何防止这种情况发生。

Answer 1

当发出嵌套的异步命令时，异步客户端可能会死锁。要修复死锁，请定义一个任务线程池，它将异步回调 (onSuccess()) 卸载到线程池，从而释放选择器线程以处理其他命令。这是一个例子：

AsyncClientPolicy policy = new AsyncClientPolicy();
policy.asyncTaskThreadPool = Executors.newCachedThreadPool(new ThreadFactory() {
        public final Thread newThread(Runnable runnable) {
            Thread thread = new Thread(runnable);
            thread.setDaemon(true);
            return thread;
        }
    });
AsyncClient client = new AsyncClient(policy, host, port);

在https://github.com/citrusleaf/aerospike-client-java/blob/master/client/src/com/aerospike/client/async/AsyncClientPolicy.java查看在线文档