@Override
  public Optional<RemoteProcedureDispatcher.RemoteOperation> remoteCallBuild(MasterProcedureEnv env,
    ServerName serverName) {
    return Optional.of(new RSProcedureDispatcher.ServerOperation(
      this, getProcId(), SplitWALCallable.class, MasterProcedureProtos.SplitWALParameter
        .newBuilder().setWalPath(walPath).build().toByteArray(),
      env.getMasterServices().getMasterActiveTime()));
  }
A remote procedure which is used to send split WAL request to region server. It will return null
if the task succeeded or return a DoNotRetryIOException. {@link SplitWALProcedure} will help
handle the situation that encounters DoNotRetryIOException. Otherwise it will retry until
success.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/SplitWALRemoteProcedure.java