最开始的问题表现为，ActiveMQ一直占用1个CPU的100%使用率。
一直也没找到问题在哪里。最后去看日志，发现日志更新特快，内容如下。
然后我想，之所以100%的CPU，也肯定是因为这个写日志的原因。
2021-05-25 22:28:29,606 | WARN | Could not load message seq: 1483 from DataLocator(39b286d3a3, 1101) | org.apache.activemq.leveldb.LevelDBClient | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,606 | WARN | No reader available for position: 39b286d852, log_infos: {324641837082=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/0000004b9629501a.log,324641837082,104859415), 518839757265=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/00000078cd4269d1.log,518839757265,0)} | org.apache.activemq.leveldb.RecordLog | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,607 | WARN | Could not load message seq: 1484 from DataLocator(39b286d852, 2100) | org.apache.activemq.leveldb.LevelDBClient | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,607 | WARN | No reader available for position: 39b286e0e8, log_infos: {324641837082=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/0000004b9629501a.log,324641837082,104859415), 518839757265=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/00000078cd4269d1.log,518839757265,0)} | org.apache.activemq.leveldb.RecordLog | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,608 | WARN | Could not load message seq: 1485 from DataLocator(39b286e0e8, 1101) | org.apache.activemq.leveldb.LevelDBClient | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,609 | WARN | No reader available for position: 39b286e597, log_infos: {324641837082=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/0000004b9629501a.log,324641837082,104859415), 518839757265=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/00000078cd4269d1.log,518839757265,0)} | org.apache.activemq.leveldb.RecordLog | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,609 | WARN | Could not load message seq: 1486 from DataLocator(39b286e597, 2100) | org.apache.activemq.leveldb.LevelDBClient | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,610 | WARN | No reader available for position: 39b286ee2d, log_infos: {324641837082=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/0000004b9629501a.log,324641837082,104859415), 518839757265=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/00000078cd4269d1.log,518839757265,0)} | org.apache.activemq.leveldb.RecordLog | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,611 | WARN | Could not load message seq: 1487 from DataLocator(39b286ee2d, 1101) | org.apache.activemq.leveldb.LevelDBClient | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,611 | WARN | No reader available for position: 39b286f2dc, log_infos: {324641837082=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/0000004b9629501a.log,324641837082,104859415), 518839757265=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/00000078cd4269d1.log,518839757265,0)} | org.apache.activemq.leveldb.RecordLog | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,612 | WARN | Could not load message seq: 1488 from DataLocator(39b286f2dc, 2100) | org.apache.activemq.leveldb.LevelDBClient | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,613 | WARN | No reader available for position: 39b286fb72, log_infos: {324641837082=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/0000004b9629501a.log,324641837082,104859415), 518839757265=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/00000078cd4269d1.log,518839757265,0)} | org.apache.activemq.leveldb.RecordLog | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,613 | WARN | Could not load message seq: 1489 from DataLocator(39b286fb72, 1101) | org.apache.activemq.leveldb.LevelDBClient | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,614 | WARN | No reader available for position: 39b2870021, log_infos: {324641837082=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/0000004b9629501a.log,324641837082,104859415), 518839757265=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/00000078cd4269d1.log,518839757265,0)} | org.apache.activemq.leveldb.RecordLog | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,614 | WARN | Could not load message seq: 1490 from DataLocator(39b2870021, 2100) | org.apache.activemq.leveldb.LevelDBClient | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,615 | WARN | No reader available for position: 39b28708b7, log_infos: {324641837082=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/0000004b9629501a.log,324641837082,104859415), 518839757265=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/00000078cd4269d1.log,518839757265,0)} | org.apache.activemq.leveldb.RecordLog | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,616 | WARN | Could not load message seq: 1491 from DataLocator(39b28708b7, 1101) | org.apache.activemq.leveldb.LevelDBClient | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,616 | WARN | No reader available for position: 39b2870d66, log_infos: {324641837082=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/0000004b9629501a.log,324641837082,104859415), 518839757265=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/00000078cd4269d1.log,518839757265,0)} | org.apache.activemq.leveldb.RecordLog | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,617 | WARN | Could not load message seq: 1492 from DataLocator(39b2870d66, 2101) | org.apache.activemq.leveldb.LevelDBClient | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,618 | WARN | No reader available for position: 39b28715fd, log_infos: {324641837082=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/0000004b9629501a.log,324641837082,104859415), 518839757265=LogInfo(/usr/local/apache-activemq-5.11.1/data/leveldb/00000078cd4269d1.log,518839757265,0)} | org.apache.activemq.leveldb.RecordLog | ActiveMQ Broker[localhost] Scheduler 2021-05-25 22:28:29,618 | WARN | Could not load message seq: 1493 from DataLocator(39b28715fd, 1101) | org.apache.activemq.leveldb.LevelDBClient | ActiveMQ Broker[localhost] Scheduler 20