Shinya Yoshida created ZOOKEEPER-4557: -----------------------------------------
Summary: MDC for myid is missing in children threads due to log4j vs logback incompatibility Key: ZOOKEEPER-4557 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-4557 Project: ZooKeeper Issue Type: Bug Affects Versions: 3.8.0 Reporter: Shinya Yoshida In 3.8.0, zookeeper is migrated from log4j to logback in ZOOKEEPER-4427. Unfortunately, logback doesn't use InheritableThreadLocal for MDC implementation because it's too dangerous unlike log4j does. https://jira.qos.ch/browse/LOGBACK-422 https://jira.qos.ch/browse/LOGBACK-624 This causes incompatibility of logging behavior. Now we missed pretty myid MDC in the logs. You can easily reproduce this issue by just downloading the zookeeper artifact and start-up locally. Zookeeper 3.7.1: {code:java} 2022-06-14 15:28:04,279 [myid:1] - INFO [ListenerHandler-localhost/127.0.0.1:3888:QuorumCnxManager$Listener$ListenerHandler@1071] - 1 is accepting connections now, my election bind port: localhost/127.0.0.1:3888 2022-06-14 15:28:04,280 [myid:1] - INFO [main:ZKAuditProvider@42] - ZooKeeper audit is disabled. 2022-06-14 15:28:04,284 [myid:1] - INFO [QuorumPeer[myid=1](plain=[0:0:0:0:0:0:0:0]:2181)(secure=disabled):QuorumPeer@1438] - LOOKING 2022-06-14 15:28:04,284 [myid:1] - INFO [QuorumPeer[myid=1](plain=[0:0:0:0:0:0:0:0]:2181)(secure=disabled):FastLeaderElection@945] - New election. My id = 1, proposed zxid=0x0 2022-06-14 15:28:04,290 [myid:1] - INFO [WorkerReceiver[myid=1]:FastLeaderElection$Messenger$WorkerReceiver@390] - Notification: my state:LOOKING; n.sid:1, n.state:LOOKING, n.leader:1, n.round:0x1, n.peerEpoch:0x0, n.zxid:0x0, message format version:0x2, n.config version:0x0 2022-06-14 15:28:04,292 [myid:1] - WARN [QuorumConnectionThread-[myid=1]-2:QuorumCnxManager@401] - Cannot open channel to 3 at election address localhost/127.0.0.1:3890 {code} zookeeper 3.8.0 {code:java} 2022-06-14 15:28:51,461 [myid:] - INFO [ListenerHandler-localhost/127.0.0.1:3888:o.a.z.s.q.QuorumCnxManager$Listener$ListenerHandler@1071] - 1 is accepting connections now, my election bind port: localhost/127.0.0.1:3888 2022-06-14 15:28:51,463 [myid:1] - INFO [main:o.a.z.a.ZKAuditProvider@42] - ZooKeeper audit is disabled. 2022-06-14 15:28:51,467 [myid:] - INFO [QuorumPeer[myid=1](plain=[0:0:0:0:0:0:0:0]:2181)(secure=disabled):o.a.z.s.q.QuorumPeer@1455] - LOOKING 2022-06-14 15:28:51,467 [myid:] - INFO [QuorumPeer[myid=1](plain=[0:0:0:0:0:0:0:0]:2181)(secure=disabled):o.a.z.s.q.FastLeaderElection@946] - New election. My id = 1, proposed zxid=0x0 2022-06-14 15:28:51,469 [myid:] - INFO [WorkerReceiver[myid=1]:o.a.z.s.q.FastLeaderElection$Messenger$WorkerReceiver@391] - Notification: my state:LOOKING; n.sid:1, n.state:LOOKING, n.leader:1, n.round:0x1, n.peerEpoch:0x0, n.zxid:0x0, message format version:0x2, n.config version:0x0 2022-06-14 15:28:51,475 [myid:] - WARN [QuorumConnectionThread-[myid=1]-1:o.a.z.s.q.QuorumCnxManager@401] - Cannot open channel to 2 at election address localhost/127.0.0.1:3889 {code} Now we couldn't see myid in the most of logs. We need to propagate myid MDC to other threads in the code. -- This message was sent by Atlassian Jira (v8.20.7#820007)