fix

Author: zcoo

fluss-server/src/test/java/org/apache/fluss/server/testutils/FlussClusterExtension.java

@@ -869,6 +869,12 @@ public void waitUntilCoordinatorServerElected() {
                 () -> zooKeeperClient.getCoordinatorLeaderAddress().isPresent(),
                 Duration.ofSeconds(10),
                 "Fail to wait coordinator server elected");
+        // Sleep 1 second to make sure coordinator server has been started and event processor started.
+        try {
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
     }
 
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