fix: make consumer group map thread-safe and guard NPE when no brokers - #710
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fix: make consumer group map thread-safe and guard NPE when no brokers#710yyqdbngt wants to merge 1 commit into
yyqdbngt wants to merge 1 commit into
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- consumerGroupMap is a plain HashMap read/written from request threads (queryGroupList/makeGroupListCache) and refreshAllGroup, which clears it without holding the lock; switch to ConcurrentHashMap to avoid ConcurrentModificationException and lost updates - makeGroupListCache dereferences subscriptionGroupWrapper without a null check; when the cluster has no brokers the wrapper stays null and getSubscriptionGroupTable() throws NPE, guard it and return early
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Motivation
Two robustness fixes in
ConsumerServiceImpl:consumerGroupMapis not thread-safeThe map is a plain
HashMapbut is read/written concurrently:queryGroupList/makeGroupListCachemutate it (on request threads), whilerefreshAllGroupcallsconsumerGroupMap.clear()without holding the same lock andrefreshGroupreads it directly. This can triggerConcurrentModificationExceptionor lost updates. Changed it to aConcurrentHashMap.NPE when the cluster has no brokers
In
makeGroupListCache,subscriptionGroupWrapperstarts asnulland is only assigned inside the per-broker loop. When the broker table is empty the wrapper staysnull, sosubscriptionGroupWrapper.getSubscriptionGroupTable()throws aNullPointerException. The empty/nullcheck is nowsubscriptionGroupWrapper == null || ...isEmpty()and returns early instead.Verification
mvn compiler:compilepasses (BUILD SUCCESS).Diff
1 file changed, +5 / -2.