Field Detail

• pool

  protected final ExecutorService pool

• cConnection

  protected final ClusterConnection cConnection

• conf

  protected final org.apache.hadoop.conf.Configuration conf

• get

  protected final Get get

• tableName

  protected final TableName tableName

• timeBeforeReplicas

  protected final int timeBeforeReplicas

Constructor Detail

• RpcRetryingCallerWithReadReplicas

  public RpcRetryingCallerWithReadReplicas(RpcControllerFactory rpcControllerFactory,
                                   TableName tableName,
                                   ClusterConnection cConnection,
                                   Get get,
                                   ExecutorService pool,
                                   int retries,
                                   int callTimeout,
                                   int timeBeforeReplicas)

Method Detail

• call

  public Result call(int operationTimeout)
              throws DoNotRetryIOException,
                     InterruptedIOException,
                     RetriesExhaustedException

  Algo: - we put the query into the execution pool. - after x ms, if we don't have a result, we add the queries for the secondary replicas - we take the first answer - when done, we cancel what's left. Cancelling means: - removing from the pool if the actual call was not started - interrupting the call if it has started Client side, we need to take into account - a call is not executed immediately after being put into the pool - a call is a thread. Let's not multiply the number of thread by the number of replicas. Server side, if we can cancel when it's still in the handler pool, it's much better, as a call can take some i/o.

  Globally, the number of retries, timeout and so on still applies, but it's per replica, not global. We continue until all retries are done, or all timeouts are exceeded.

  Throws:

  DoNotRetryIOException

  InterruptedIOException

  RetriesExhaustedException