Paul Millar created ZOOKEEPER-2991: -------------------------------------- Summary: Server logs error on shutdown Key: ZOOKEEPER-2991 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-2991 Project: ZooKeeper Issue Type: Bug Components: server Affects Versions: 3.4.11, 3.4.10 Reporter: Paul Millar
Commit d497aac4 introduced the ZooKeeperServer#registerServerShutdownHandler method and corresponding ZooKeeperServerShutdownHandler class. Both the method and class are package-protected, resulting in the expectation that non-ZK code should not use either. However, if registerServerShutdownHandler is *not* called, then ZK will log an error: {quote}ZKShutdownHandler is not registered, so ZooKeeper server won't take any action on ERROR or SHUTDOWN server state changes {quote} There are several problems here. In order of importance (for me, at least!) First, (most important) this certainly should not be logged as an error. Depending on usage, there may be no need for a shutdown handler. Always logging an error (with no opportunity to silence it) is therefore wrong. Second, the ability to learn of state changes may be of general interest (monitoring, etc); however, this is not possible if the method is protected. Third, the method accepts a concrete class that is designed to use a CountDownLatch. This is not appropriate in all cases. The method should be updated to accept an interface. -- This message was sent by Atlassian JIRA (v7.6.3#76005)