[jira] [Created] (HBASE-21291) Bypass doesn't work for state-machine procedures

["Jingyun Tian (JIRA)" <ji...@apache.org>]

Jingyun Tian created HBASE-21291:
------------------------------------

             Summary: Bypass doesn't work for state-machine procedures
                 Key: HBASE-21291
                 URL: https://issues.apache.org/jira/browse/HBASE-21291
             Project: HBase
          Issue Type: Improvement
    Affects Versions: 2.2.0
            Reporter: Jingyun Tian


{code}
      if (!procedure.isFailed()) {
        if (subprocs != null) {
          if (subprocs.length == 1 && subprocs[0] == procedure) {
            // Procedure returned itself. Quick-shortcut for a state machine-like procedure;
            // i.e. we go around this loop again rather than go back out on the scheduler queue.
            subprocs = null;
            reExecute = true;
            LOG.trace("Short-circuit to next step on pid={}", procedure.getProcId());
          } else {
            // Yield the current procedure, and make the subprocedure runnable
            // subprocs may come back 'null'.
            subprocs = initializeChildren(procStack, procedure, subprocs);
            LOG.info("Initialized subprocedures=" +
              (subprocs == null? null:
                Stream.of(subprocs).map(e -> "{" + e.toString() + "}").
                collect(Collectors.toList()).toString()));
          }
        } else if (procedure.getState() == ProcedureState.WAITING_TIMEOUT) {
          LOG.debug("Added to timeoutExecutor {}", procedure);
          timeoutExecutor.add(procedure);
        } else if (!suspended) {
          // No subtask, so we are done
          procedure.setState(ProcedureState.SUCCESS);
        }
      }
{code}
Currently implementation of ProcedureExecutor will set the reExcecute to true for state machine like procedure. Then if this procedure is stuck at one certain state, it will loop forever.
{code}
          IdLock.Entry lockEntry = procExecutionLock.getLockEntry(proc.getProcId());
          try {
            executeProcedure(proc);
          } catch (AssertionError e) {
            LOG.info("ASSERT pid=" + proc.getProcId(), e);
            throw e;
          } finally {
            procExecutionLock.releaseLockEntry(lockEntry);
{code}
Since procedure will get the IdLock and release it after execution done, state machine procedure will never release IdLock until it is finished.
Then bypassProcedure doesn't work because is will try to grab the IdLock at first.
{code}
    IdLock.Entry lockEntry = procExecutionLock.tryLockEntry(procedure.getProcId(), lockWait);
{code}



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