Stop getSafeCommitInfo() blocking on engine reset

yungene · yungene · commit f50a5eefdd8e · 2025-11-28T11:07:00.000Z
Change IndexShard.getSafeCommitInfo() to stop blocking on engine reset.
This eliminates deadlock risk between engine reset and retention lease
syncing.

Relates ES-13669
diff --git a/server/src/main/java/org/elasticsearch/index/shard/IndexShard.java b/server/src/main/java/org/elasticsearch/index/shard/IndexShard.java
@@ -3778,9 +3778,12 @@ public boolean useRetentionLeasesInPeerRecovery() {
         return useRetentionLeasesInPeerRecovery;
     }
 
+    /**
+     * @return SafeCommitInfo of the current engine. But if engine is null or engine is locked for reset then returns SafeCommitInfo.EMPTY.
+     */
     private SafeCommitInfo getSafeCommitInfo() {
-        final Engine engine = getEngineOrNull();
-        return engine == null ? SafeCommitInfo.EMPTY : engine.getSafeCommitInfo();
+        return tryWithEngineOrNull(engine -> engine == null ? SafeCommitInfo.EMPTY : engine.getSafeCommitInfo());
+
     }
 
     class ShardEventListener implements Engine.EventListener {

Original file line number	Diff line number	Diff line change
`@@ -3778,9 +3778,12 @@ public boolean useRetentionLeasesInPeerRecovery() {`
`3778`	`3778`	`return useRetentionLeasesInPeerRecovery;`
`3779`	`3779`	`}`
`3780`	`3780`
	`3781`	`+ /**`
	`3782`	`+ * @return SafeCommitInfo of the current engine. But if engine is null or engine is locked for reset then returns SafeCommitInfo.EMPTY.`
	`3783`	`+ */`
`3781`	`3784`	`private SafeCommitInfo getSafeCommitInfo() {`
`3782`		`- final Engine engine = getEngineOrNull();`
`3783`		`- return engine == null ? SafeCommitInfo.EMPTY : engine.getSafeCommitInfo();`
	`3785`	`+ return tryWithEngineOrNull(engine -> engine == null ? SafeCommitInfo.EMPTY : engine.getSafeCommitInfo());`
	`3786`	`+`
`3784`	`3787`	`}`
`3785`	`3788`
`3786`	`3789`	`class ShardEventListener implements Engine.EventListener {`