protected boolean storeCheckpoint(DispatcherState curState, Checkpoint cp, SCN winScn)
throws IOException {
boolean debugEnabled = _log.isDebugEnabled();
if (debugEnabled) _log.debug("About to store checkpoint");
boolean success = true;
// processBatch - returns false ; then
ConsumerCallbackResult callbackResult = getAsyncCallback().onCheckpoint(winScn);
boolean persistCheckpoint =
!ConsumerCallbackResult.isSkipCheckpoint(callbackResult)
&& ConsumerCallbackResult.isSuccess(callbackResult);
if (persistCheckpoint) {
if (null != getCheckpointPersistor()) {
getCheckpointPersistor().storeCheckpointV3(getSubsciptionsList(), cp, _registrationId);
++_numCheckPoints;
}
curState.storeCheckpoint(cp, winScn);
removeEvents(curState);
if (debugEnabled) _log.debug("Checkpoint saved: " + cp.toString());
} else {
if (debugEnabled)
_log.debug("Checkpoint " + cp + " not saved as callback returned " + callbackResult);
}
return success;
}
private boolean processErrorEvent(DispatcherState curState, DbusEventInternalReadable nextEvent) {
boolean success = false;
DbusErrorEvent errorEvent = null;
if (nextEvent.isErrorEvent()) {
errorEvent = DbusEventSerializable.getErrorEventFromDbusEvent(nextEvent);
if (null == errorEvent) {
_log.error("Null error event received at dispatcher");
} else {
_log.info("Delivering error event to consumers: " + errorEvent);
ConsumerCallbackResult callbackResult = ConsumerCallbackResult.ERROR;
try {
callbackResult = _asyncCallback.onError(errorEvent.returnActualException());
} catch (RuntimeException e) {
_log.error("Internal onError error: " + e.getMessage(), e);
}
success = ConsumerCallbackResult.isSuccess(callbackResult);
}
} else {
_log.error("Unexcpected event received while DbusErrorEvent is expected! " + nextEvent);
}
return success;
}
protected void doStartDispatchEvents() {
boolean debugEnabled = _log.isDebugEnabled();
if (debugEnabled) _log.debug("Entered startDispatch");
_asyncCallback.setSourceMap(_internalState.getSources());
getStatus().start();
ConsumerCallbackResult callbackResult = ConsumerCallbackResult.ERROR;
try {
callbackResult = _asyncCallback.onStartConsumption();
} catch (RuntimeException e) {
_log.error("Internal startConsumption error: " + e.getMessage(), e);
}
Boolean callSuccess = ConsumerCallbackResult.isSuccess(callbackResult);
if (!callSuccess) {
// getStatus().suspendOnError(new RuntimeException("Unable to start processing of
// events"));
_log.error("StartConsumption failed.");
_internalState.switchToStopDispatch();
doStopDispatch(_internalState);
} else {
_stopDispatch.set(false);
_internalState.switchToExpectEventWindow();
doDispatchEvents();
}
}
protected boolean doEndStreamSource(DispatcherState curState) {
boolean success = true;
boolean debugEnabled = _log.isDebugEnabled();
if (debugEnabled) _log.debug("Entered endSource");
if (!curState.getStateId().equals(StateId.END_STREAM_SOURCE)) {
success = false;
_log.error("END_STREAM_SOURCE state expected but found :" + curState.getStateId());
} else if (null == curState.getCurrentSource()) {
success = false;
_log.error("Missing source information in the current state");
} else if (curState.getCurrentSource().getId() >= 0) {
String sourceName = curState.getCurrentSource().getName();
ConsumerCallbackResult callbackResult = ConsumerCallbackResult.ERROR;
try {
callbackResult =
getAsyncCallback().onEndSource(sourceName, curState.getCurrentSourceSchema());
} catch (RuntimeException e) {
_log.error("Internal onEndSource error:" + e.getMessage(), e);
}
success = ConsumerCallbackResult.isSuccess(callbackResult);
if (!success) {
_log.error("Method endSource() failed for the source : " + sourceName);
} else {
if (debugEnabled) _log.debug("endSource succeeded:" + sourceName);
curState.resetSourceInfo();
curState.switchToExpectStreamDataEvents();
}
}
return success;
}
protected boolean doEndStreamEventWindow(DispatcherState curState) {
boolean success = true;
boolean debugEnabled = _log.isDebugEnabled();
if (debugEnabled) _log.debug("Entered endDataEventSequence");
if (!curState.getStateId().equals(StateId.END_STREAM_EVENT_WINDOW)) {
success = false;
_log.error("END_STREAM_EVENT_WINDOW state expected but found :" + curState.getStateId());
} else {
ConsumerCallbackResult callbackResult = ConsumerCallbackResult.ERROR;
try {
callbackResult = getAsyncCallback().onEndDataEventSequence(curState.getEndWinScn());
} catch (RuntimeException e) {
_log.error("Internal onEndDataEventSequence error: " + e.getMessage(), e);
}
success = ConsumerCallbackResult.isSuccess(callbackResult);
if (success) {
if (debugEnabled)
_log.debug("endDataEventSequence callback succeeded:" + curState.getEndWinScn());
} else {
_log.error(
"endDataEventSequence callback failed, the end window scn is: "
+ curState.getEndWinScn());
}
}
return success;
}
protected boolean processDataEventsBatch(DispatcherState curState) {
DbusPrettyLogUtils.logExceptionAtDebug("Flushing batched events", null, _log);
ConsumerCallbackResult callbackResult = getAsyncCallback().flushCallQueue(-1);
boolean success = ConsumerCallbackResult.isSuccess(callbackResult);
if (!success) {
_log.error("Error dispatching events, the consumer callback returned an error");
}
return success;
}
protected boolean processDataEvent(DispatcherState curState, DbusEvent event) {
ConsumerCallbackResult callbackResult =
getAsyncCallback().onDataEvent(event, curState.getEventDecoder());
boolean success = ConsumerCallbackResult.isSuccess(callbackResult);
if (!success) {
_log.error("Method onDataEvent failed on consumer callback returned an error.");
} else {
_log.debug("Event queued: " + event.toString());
}
return success;
}
protected void doRollback(
DispatcherState curState, SCN rollbackScn, boolean checkRetries, boolean regressItr) {
boolean success = true;
boolean debugEnabled = _log.isDebugEnabled();
if (!curState.getStateId().equals(StateId.ROLLBACK)) {
success = false;
_log.error(
"ROLLBACK state is expected by the dispatcher, but the current state is:"
+ curState.getStateId());
}
int retriesLeft = Integer.MAX_VALUE;
if (checkRetries) {
retriesLeft = getStatus().getRetriesLeft();
_log.info(
"Rolling back the dispatcher to last successful checkpoint. Number of remaining retries for dispatcher to replay events = "
+ retriesLeft);
success = success && (retriesLeft > 0);
if (success) {
if (0 == getStatus().getRetriesNum()) getStatus().retryOnError("rollback");
else getStatus().retryOnLastError();
}
}
if (success) {
Checkpoint lastCp = curState.getLastSuccessfulCheckpoint();
if ((null != lastCp) || (!regressItr)) {
ConsumerCallbackResult callbackResult = ConsumerCallbackResult.ERROR;
try {
_log.info("Rolling back to SCN : " + rollbackScn);
callbackResult = getAsyncCallback().onRollback(rollbackScn);
} catch (RuntimeException e) {
_log.error("Internal onRollback error: " + e.getMessage(), e);
}
success = ConsumerCallbackResult.isSuccess(callbackResult);
if (success) {
if (debugEnabled) _log.debug("Rollback consumer callback succeeded");
} else {
_log.error("Rollback consumer callback failed");
}
}
if (regressItr) {
if (null != curState.getLastSuccessfulIterator()) {
_log.info(
"Rolled back to last successful checkpoint position in the buffer: "
+ curState.getLastSuccessfulIterator());
_currentWindowSizeInBytes = 0;
curState.switchToReplayDataEvents();
} else {
_log.fatal(
"Unable to rollback, this usually means that the events belonging to the last checkpoint"
+ " are no longer to be found in the buffer. Please checkpoint more frequently to avoid this. Restarting the client "
+ "will fix this problem, last checkpoint found: \n"
+ lastCp);
curState.switchToClosed();
}
}
} else {
DispatcherRetriesExhaustedException exp = new DispatcherRetriesExhaustedException();
_log.info("Invoke onError callback as dispatcher retries have exhausted");
getAsyncCallback().onError(exp);
curState.switchToClosed();
}
}
