errors while publish version to all backends java.lang.NullPointerException: null

麻烦补充下导致这个报错的具体操作，我们来尝试复现并定位问题

最新补充：这个2.1.4版本修复了，推荐升级2.1.4版本
https://github.com/apache/doris/pull/35475

这是Observer节点的错误日志信息:
2024-07-02 09:49:29,633 INFO (mysql-nio-pool-6340|186582) [StmtExecutor.handleQueryStmt():1624] Query b6a72f8089a548ef-9167e8e70d9c0244 finished
2024-07-02 09:49:29,634 INFO (mysql-nio-pool-6338|186565) [StmtExecutor.handleQueryStmt():1624] Query 3cc4ae71aea94910-bb1d23bf51fb9d6c finished
2024-07-02 09:49:29,635 WARN (mysql-nio-pool-6340|186582) [ConnectProcessor.handleQueryException():435] Process one query failed because unknown reason:
java.lang.Exception: Failed to get master client.
at org.apache.doris.qe.MasterOpExecutor.forward(MasterOpExecutor.java:108) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.doris.qe.MasterOpExecutor.execute(MasterOpExecutor.java:82) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.doris.qe.StmtExecutor.forwardToMaster(StmtExecutor.java:1023) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.doris.qe.StmtExecutor.executeByNereids(StmtExecutor.java:676) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.doris.qe.StmtExecutor.execute(StmtExecutor.java:533) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.doris.qe.StmtExecutor.execute(StmtExecutor.java:512) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.doris.qe.ConnectProcessor.executeQuery(ConnectProcessor.java:307) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.doris.qe.ConnectProcessor.handleQuery(ConnectProcessor.java:203) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.doris.qe.MysqlConnectProcessor.handleQuery(MysqlConnectProcessor.java:177) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.doris.qe.MysqlConnectProcessor.dispatch(MysqlConnectProcessor.java:205) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.doris.qe.MysqlConnectProcessor.processOnce(MysqlConnectProcessor.java:258) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.doris.mysql.ReadListener.lambda$handleEvent$0(ReadListener.java:52) ~[doris-fe.jar:1.2-SNAPSHOT]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[?:1.8.0_382]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[?:1.8.0_382]
at java.lang.Thread.run(Thread.java:750) ~[?:1.8.0_382]
Caused by: org.apache.thrift.transport.TTransportException: java.net.ConnectException: Connection refused (Connection refused)
at org.apache.thrift.transport.TSocket.open(TSocket.java:255) ~[libthrift-0.16.0.jar:0.16.0]
at org.apache.doris.common.GenericPool$ThriftClientFactory.create(GenericPool.java:143) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.doris.common.GenericPool$ThriftClientFactory.create(GenericPool.java:126) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.commons.pool2.BaseKeyedPooledObjectFactory.makeObject(BaseKeyedPooledObjectFactory.java:62) ~[commons-pool2-2.2.jar:2.2]
at org.apache.commons.pool2.impl.GenericKeyedObjectPool.create(GenericKeyedObjectPool.java:1012) ~[commons-pool2-2.2.jar:2.2]
at org.apache.commons.pool2.impl.GenericKeyedObjectPool.borrowObject(GenericKeyedObjectPool.java:356) ~[commons-pool2-2.2.jar:2.2]
at org.apache.commons.pool2.impl.GenericKeyedObjectPool.borrowObject(GenericKeyedObjectPool.java:277) ~[commons-pool2-2.2.jar:2.2]
at org.apache.doris.common.GenericPool.borrowObject(GenericPool.java:99) ~[doris-fe.jar:1.2-SNAPSHOT]
at org.apache.doris.qe.MasterOpExecutor.forward(MasterOpExecutor.java:105) ~[doris-fe.jar:1.2-SNAPSHOT]
... 14 more
Caused by: java.net.ConnectException: Connection refused (Connection refused)