xyuanlu commented on code in PR #3043: URL: https://github.com/apache/helix/pull/3043#discussion_r2133457342
########## helix-core/src/main/java/org/apache/helix/controller/stages/MessageGenerationPhase.java: ########## @@ -290,6 +321,79 @@ private void generateMessage(final Resource resource, final BaseControllerDataPr } // end of for-each-partition } + /** + * Calculate the target active replica count after state convergence. + * This method counts only replicas that will be actively serving traffic after all + * state transitions complete. It excludes replicas being dropped or in inactive states. + * + * @param instanceStateMap Map of instance to desired state + * @param stateModelDef The state model definition + * @return Number of active replicas after convergence + */ + private int calculateTargetActiveReplicaCount(Map<String, String> instanceStateMap, + StateModelDefinition stateModelDef) { + int targetActiveReplicaCount = 0; + String initialState = stateModelDef.getInitialState(); + + for (String desiredState : instanceStateMap.values()) { + // Count potential active replicas after convergence (not initial state/dropped state) + // Note : calling it potential as counting active replicas after convergence is hard as upward state transitions are in progress too. + if (desiredState != null && !desiredState.equals(initialState) + && !desiredState.equals(NO_DESIRED_STATE) + && !desiredState.equals(HelixDefinedState.DROPPED.name())) { + targetActiveReplicaCount++; + } + } + + return targetActiveReplicaCount; + } + + /** + * 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); + } + + /** + * 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> getPendingTransitionsToTopOrSecondTopStates(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 (stateModelDef.isUpwardStateTransition(fromState, toState) + && !isSecondTopState(fromState, stateModelDef) + && (isSecondTopState(toState, stateModelDef) || stateModelDef.getTopState().contains(toState))) { Review Comment: why we want to exclude secondary to top? -- 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: reviews-unsubscr...@helix.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@helix.apache.org For additional commands, e-mail: reviews-h...@helix.apache.org