title: Couchbase concurrent timeout exception : Java SDK
body: <p>I am working with java in a maven project. I was using couchbase 2.3.1 but in trying to resolve this issue I rolled back to 2.2.8 to no avail. </p>
  
  <p>The issue I get is that while I do get date through to my couchbase cluster I am seeing alot of this:</p>
  
  <pre><code>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)
  </code></pre>
  
  <p>Below are the settings for my couchbase environment:</p>
  
  <pre><code>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}
  </code></pre>
  
  <p>Im not really too sure what to look at here. As far as I can tell there should be a decent enough connection between the server where the app is running and the couchbase cluster. Any help or direction on this would be helpful. Here is a snippet from where the error is being thrown.</p>
  
  <pre><code>LockableItem&lt;InnerVertex&gt; 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();
      }
  </code></pre>