[GitHub] [pulsar] jerrypeng commented on a change in pull request #5371: fix potential deadlock that can occur in addConsumer

[GitBox <gi...@apache.org>]

jerrypeng commented on a change in pull request #5371: fix potential deadlock that can occur in addConsumer
URL: https://github.com/apache/pulsar/pull/5371#discussion_r336267491
 
 

 ##########
 File path: pulsar-broker/src/main/java/org/apache/pulsar/broker/service/persistent/PersistentDispatcherMultipleConsumers.java
 ##########
 @@ -158,9 +158,13 @@ public synchronized void addConsumer(Consumer consumer) throws BrokerServiceExce
     private boolean isConsumersExceededOnTopic() {
         Policies policies;
         try {
+            // Use getDataIfPresent from zk cache to make the call non-blocking and prevent deadlocks in addConsumer
             policies = topic.getBrokerService().pulsar().getConfigurationCache().policiesCache()
-                    .get(AdminResource.path(POLICIES, TopicName.get(topic.getName()).getNamespace()))
-                    .orElseGet(() -> new Policies());
+                    .getDataIfPresent(AdminResource.path(POLICIES, TopicName.get(topic.getName()).getNamespace()));
+
+            if (policies == null) {
+                policies = new Policies();
 
 Review comment:
   @rdhabalia I don't think that is correct because we still have to check serviceConfig.getMaxConsumersPerTopic() here:
   
   https://github.com/apache/pulsar/pull/5371/files#diff-5cc001bf2b64aad097762e99c5b78e4aR171

----------------------------------------------------------------
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.
 
For queries about this service, please contact Infrastructure at:
users@infra.apache.org


With regards,
Apache Git Services