dongxiaoman commented on a change in pull request #8272: URL: https://github.com/apache/pinot/pull/8272#discussion_r817416806
########## File path: pinot-core/src/main/java/org/apache/pinot/core/query/reduce/StreamingReduceService.java ########## @@ -106,15 +108,17 @@ public BrokerResponseNative reduceOnStreamResponse(BrokerRequest brokerRequest, return brokerResponseNative; } - private static void processIterativeServerResponse(StreamingReducer reducer, ExecutorService executorService, + @VisibleForTesting + static void processIterativeServerResponse(StreamingReducer reducer, ExecutorService executorService, Map<ServerRoutingInstance, Iterator<Server.ServerResponse>> serverResponseMap, long reduceTimeOutMs, - ExecutionStatsAggregator aggregator) throws Exception { + ExecutionStatsAggregator aggregator) throws ExecutionException { int cnt = 0; - Future[] futures = new Future[serverResponseMap.size()]; - CountDownLatch countDownLatch = new CountDownLatch(serverResponseMap.size()); - + Future<Void>[] futures = new Future[serverResponseMap.size()]; + // based on ideas from on https://stackoverflow.com/questions/19348248/waiting-on-a-list-of-future + // mostly because we need to handle and transfer the exception in threads into caller thread. + ExecutorCompletionService<Void> countDownHelper = new ExecutorCompletionService<>(executorService); Review comment: Thought about this, at first thought gRPC calls returns a `Future<Void>` and it is painful to convert to `CompletableFuture`. But I found https://stackoverflow.com/questions/23301598/transform-java-future-into-a-completablefuture , because we are creating Future by `ExecutorService.submit()` we can switch to use `CompletableFuture.supplyAsync()` to create CompletableFuture "natively". Tried it out and it works. Now the code is shorter and cleaner. -- 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: commits-unsubscr...@pinot.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org