From: Kai Moritz <kai@juplo.de>
Date: Sun, 24 Sep 2023 19:39:01 +0000 (+0200)
Subject: fix: The actual position has to be requested from the consumer
X-Git-Tag: rebase--2024-01-27--15-10~1
X-Git-Url: http://juplo.de/gitweb/?a=commitdiff_plain;h=51e150afbe6130d4fb6c8e8fda12732c7b083651;p=demos%2Fkafka%2Fchat

fix: The actual position has to be requested from the consumer

* If the last seen offset and the current offset differ, although the
  partition did not contain any messages between this offsets, the loading
  process got stuck, because the position never advanced.
* Therefore, the actual position, that is compared against the read
  end-offset, has to be requested from the consumer.
---

diff --git a/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/DataChannel.java b/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/DataChannel.java
index c2908461..5680360f 100644
--- a/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/DataChannel.java
+++ b/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/DataChannel.java
@@ -279,7 +279,12 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
     return IntStream
         .range(0, numShards)
         .filter(shard -> isShardOwned[shard])
-        .allMatch(shard -> nextOffset[shard] >= currentOffset[shard]);
+        .allMatch(shard ->
+        {
+          TopicPartition partition = new TopicPartition(topic, shard);
+          long position = consumer.position(partition);
+          return position >= currentOffset[shard];
+        });
   }
 
   private void pauseAllOwnedPartions()