我在 Maven 项目中使用 Java。我使用的是 couchbase 2.3.1，但在尝试解决此问题时，我回滚到 2.2.8 无济于事。

我遇到的问题是，当我通过我的 couchbase 集群获取日期时，我看到了很多这样的东西:

java.lang.RuntimeException: java.util.concurrent.TimeoutException
at com.couchbase.client.java.util.Blocking.blockForSingle(Blocking.java:75)
at com.couchbase.client.java.CouchbaseBucket.upsert(CouchbaseBucket.java:359)
at com.couchbase.client.java.CouchbaseBucket.upsert(CouchbaseBucket.java:354)

以下是我的 couchbase 环境的设置:

CouchbaseEnvironment: {sslEnabled=false, sslKeystoreFile='null', sslKeystorePassword='null', queryEnabled=false, queryPort=8093, bootstrapHttpEnabled=true, bootstrapCarrierEnabled=true, bootstrapHttpDirectPort=8091, bootstrapHttpSslPort=18091, bootstrapCarrierDirectPort=11210, bootstrapCarrierSslPort=11207, ioPoolSize=24, computationPoolSize=24, responseBufferSize=16384, requestBufferSize=16384, kvServiceEndpoints=1, viewServiceEndpoints=1, queryServiceEndpoints=1, searchServiceEndpoints=1, ioPool=NioEventLoopGroup, coreScheduler=CoreScheduler, eventBus=DefaultEventBus, packageNameAndVersion=couchbase-java-client/2.2.8 (git: 2.2.8, core: 1.2.9), dcpEnabled=false, retryStrategy=BestEffort, maxRequestLifetime=75000, retryDelay=ExponentialDelay{growBy 1.0 MICROSECONDS, powers of 2; lower=100, upper=100000}, reconnectDelay=ExponentialDelay{growBy 1.0 MILLISECONDS, powers of 2; lower=32, upper=4096}, observeIntervalDelay=ExponentialDelay{growBy 1.0 MICROSECONDS, powers of 2; lower=10, upper=100000}, keepAliveInterval=30000, autoreleaseAfter=2000, bufferPoolingEnabled=true, tcpNodelayEnabled=true, mutationTokensEnabled=false, socketConnectTimeout=1000, dcpConnectionBufferSize=20971520, dcpConnectionBufferAckThreshold=0.2, dcpConnectionName=dcp/core-io, callbacksOnIoPool=false, queryTimeout=75000, viewTimeout=75000, kvTimeout=2500, connectTimeout=5000, disconnectTimeout=25000, dnsSrvEnabled=false}

我不太确定在这里看什么。据我所知，运行应用程序的服务器和 couchbase 集群之间应该有足够好的连接。对此的任何帮助或指导都会有所帮助。以下是引发错误的片段。

LockableItem<InnerVertex> lv = this.getInnerVertex(id);
lv.lock();
    try {
        String content;
        try {
            content = mapper.writeValueAsString(lv.item);
        } catch (JsonProcessingException e) {
            LOG.warning(e.getMessage());
            return;
        }
        RawJsonDocument d = RawJsonDocument.create(VertexId.toKey(id), content);
        bucket.upsert(d);
    } finally {
        lv.unlock();
    }

最佳答案

我一直在寻找答案。我知道有很多解决方案都在谈论异常。 jar码我也查了，说是超时异常。

根本原因分析

错误发生在 couchbase 的以下部分:https://github.com/couchbase/couchbase-java-client/blob/master/src/main/java/com/couchbase/client/java/util/Blocking.java#L71

public static <T> T blockForSingle(final Observable<? extends T> observable, final long timeout,
    final TimeUnit tu) {
    final CountDownLatch latch = new CountDownLatch(1);
    TrackingSubscriber<T> subscriber = new TrackingSubscriber<T>(latch);

    observable.subscribe(subscriber);

    try {
        if (!latch.await(timeout, tu)) { // From here, this error occurs.
            throw new RuntimeException(new TimeoutException());
        }
} 

If the timeout kicks in, a TimeoutException nested in a RuntimeException is thrown to be fully compatible with the Observable.timeout(long, TimeUnit) behavior.

资源链接:

http://docs.couchbase.com/sdk-api/couchbase-java-client-2.2.0/com/couchbase/client/java/util/Blocking.html

您的配置分析及解决方案:

你的couchbase环境connectionTimeout是5000ms或者5sec，这是连接超时的默认值。

您需要将此值增加到 10000ms 或更大。您的问题将得到解决。

//this tunes the SDK (to customize connection timeout)
CouchbaseEnvironment env = DefaultCouchbaseEnvironment.builder()
        .connectTimeout(10000) //10000ms = 10s, default is 5s
        .build();

完整的解决方案

Simonbasle在本教程中给出了完整的解决方案:

From the short log, it looks like the SDK is able to connect to the node, but takes a little much time to open the bucket. How good is the network link between the two machines? Is this a VM/cloud machine?

What you can try to do is increase the connect timeout:

public class NoSQLTest {
public static void main(String[] args) {
        try {
            //this tunes the SDK (to customize connection timeout)
            CouchbaseEnvironment env = DefaultCouchbaseEnvironment.builder()
                    .connectTimeout(10000) //10000ms = 10s, default is 5s
                    .build();
            System.out.println("Create connection");
            //use the env during cluster creation to apply
            Cluster cluster = CouchbaseCluster.create(env, "10.115.224.94");
            System.out.println("Try to openBucket");
            Bucket bucket = cluster.openBucket("beer-sample"); //you can also force a greater timeout here (cluster.openBucket("beer-sample", 10, TimeUnit.SECONDS))
            System.out.println("disconnect");
            cluster.disconnect();
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
}

As a side note, you should always reuse the CouchbaseEnvironment, CouchbaseCluster and Bucket instances once created (usually by making them public static somewhere, or a Spring singleton, etc...). These are thread safe and should be shared (and they are expensive to create anyway).

资源链接:

1. Couchbase connection timeout with Java SDK

关于java - Couchbase并发超时异常: Java SDK，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40758934/