csudharsanan commented on code in PR #3043:
URL: https://github.com/apache/helix/pull/3043#discussion_r2125222416
##########
helix-core/src/main/java/org/apache/helix/controller/stages/MessageGenerationPhase.java:
##########
@@ -290,6 +315,113 @@ private void generateMessage(final Resource resource,
final BaseControllerDataPr
} // end of for-each-partition
}
+ /**
+ * Check if a state is a top state
+ * @param state The state to check
+ * @param stateModelDef The state model definition
+ * @return True if it's a top state, false otherwise
+ */
+ private boolean isTopState(String state, StateModelDefinition stateModelDef)
{
+ return stateModelDef.getTopState().contains(state);
+ }
+
+ /**
+ * Check if a state is a second top state
+ * @param state The state to check
+ * @param stateModelDef The state model definition
+ * @return True if it's a second top state, false otherwise
+ */
+ private boolean isSecondTopState(String state, StateModelDefinition
stateModelDef) {
+ return stateModelDef.getSecondTopStates().contains(state);
+ }
+
+ /**
+ * Check if a state transition is already in the pending messages
+ * @param resourceName The resource name
+ * @param partition The partition
+ * @param instanceName The instance name
+ * @param fromState The from state
+ * @param toState The to state
+ * @param pendingMessages The list of pending messages
+ * @return True if the state transition is already in pending messages,
false otherwise
+ */
+ private boolean isInPendingMessages(String resourceName, Partition
partition, String instanceName,
+ String fromState, String toState, List<Message> pendingMessages) {
+
+ for (Message message : pendingMessages) {
+ if (message.getResourceName().equals(resourceName)
+ && message.getPartitionName().equals(partition.getPartitionName())
+ && message.getTgtName().equals(instanceName) &&
message.getFromState().equals(fromState)
+ && message.getToState().equals(toState)) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ /**
+ * Check if a state transition is upward
+ * @param fromState The from state
+ * @param toState The to state
+ * @param stateModelDef The state model definition
+ * @return True if it's an upward state transition, false otherwise
+ */
+ private boolean isUpwardStateTransition(String fromState, String toState,
+ StateModelDefinition stateModelDef) {
+
+ if (fromState == null || toState == null) {
+ return false;
+ }
+
+ Map<String, Integer> statePriorityMap =
stateModelDef.getStatePriorityMap();
+
+ Integer fromStateWeight = statePriorityMap.get(fromState);
+ Integer toStateWeight = statePriorityMap.get(toState);
+
+ if (fromStateWeight == null || toStateWeight == null) {
+ return false;
+ }
+
+ return toStateWeight < fromStateWeight;
+ }
+
+ /**
+ * Get pending upward state transition messages from non-second top state to
second top or top
+ * state
+ * @param resourceName The resource name
+ * @param partition The partition
+ * @param currentStateOutput The current state output
+ * @param stateModelDef The state model definition
+ * @return List of pending messages for upward state transitions
+ */
+ private List<Message> getPendingUpwardStateTransitionMessages(String
resourceName,
+ Partition partition, CurrentStateOutput currentStateOutput,
+ StateModelDefinition stateModelDef) {
+ List<Message> pendingUpwardSTMessages = new ArrayList<>();
+
+ // Instance -> PendingMessage
+ Map<String, Message> pendingMessages =
+ currentStateOutput.getPendingMessageMap(resourceName, partition);
+
+ if (pendingMessages != null && !pendingMessages.isEmpty()) {
+ for (Message message : pendingMessages.values()) {
+ String fromState = message.getFromState();
+ String toState = message.getToState();
+
+ // Check if it's an upward state transition from non-second top state
to second top or top
+ // state
+ if (isUpwardStateTransition(fromState, toState, stateModelDef)
+ && !isSecondTopState(fromState, stateModelDef)
+ && (isSecondTopState(toState, stateModelDef) ||
isTopState(toState, stateModelDef))) {
Review Comment:
I need to correct my earlier comment regarding controller-side
prioritization logic. We don't actually do controller-side prioritization in
this implementation. The Helix controller doesn't have enough context about
application-specific needs, so we deliberately avoid making these decisions at
the framework level.
For example, one system's BOOTSTRAP → FOLLOWER transition might be slow and
less critical, while OFFLINE → BOOTSTRAP is fast and critical for availability.
Without understanding each client's state model semantics and business
priorities, we can't make optimal prioritization decisions at the controller
level.
Instead, we provide the currentReplicaNumber metadata to clients and let
them implement custom ExecutorService logic based on their specific
requirements. This approach keeps Helix flexible while still enabling
application-aware prioritization where it actually matters.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
