RATIS-2321. Fix NPE in ServerState after continuous leader changes (#1280)

jt2594838 · web-flow · commit 6d471e649cca · 2025-08-13T09:17:22.000-07:00
diff --git a/ratis-server/src/main/java/org/apache/ratis/server/impl/ServerState.java b/ratis-server/src/main/java/org/apache/ratis/server/impl/ServerState.java
@@ -265,7 +265,7 @@ void setLeader(RaftPeerId newLeaderId, Object op) {
         suffix = "";
       } else {
         final Timestamp previous = lastNoLeaderTime.getAndSet(null);
-        suffix = ", leader elected after " + previous.elapsedTimeMs() + "ms";
+        suffix = ", leader elected after " + (previous != null ? previous.elapsedTimeMs() : 0) + "ms";
         server.setFirstElection(op);
         server.getStateMachine().event().notifyLeaderChanged(getMemberId(), newLeaderId);
       }

Original file line number	Diff line number	Diff line change
`@@ -265,7 +265,7 @@ void setLeader(RaftPeerId newLeaderId, Object op) {`
`265`	`265`	`suffix = "";`
`266`	`266`	`} else {`
`267`	`267`	`final Timestamp previous = lastNoLeaderTime.getAndSet(null);`
`268`		`- suffix = ", leader elected after " + previous.elapsedTimeMs() + "ms";`
	`268`	`+ suffix = ", leader elected after " + (previous != null ? previous.elapsedTimeMs() : 0) + "ms";`
`269`	`269`	`server.setFirstElection(op);`
`270`	`270`	`server.getStateMachine().event().notifyLeaderChanged(getMemberId(), newLeaderId);`
`271`	`271`	`}`