DB Exception - Could not acquire change log lock. Currently locked by 6be609b3a4
Asked by Joacim J:

Hi,

I am getting a lot of DB fault in atlassian-confluence.log

Confluence v6.15.2 running in Docker using PostgreSQL v9.6.12.

How can I resolve these?

```
2019-04-23 16:40:22,547 ERROR [Caesium-1-1] [migration.agent.queue.QueueBroker] error An error occurred when getting the next batch for consumer type: CONFLUENCE_EXPORT. Message: javax.persistence.PersistenceException: Failed to update database schema
com.atlassian.util.concurrent.LazyReference$InitializationException: javax.persistence.PersistenceException: Failed to update database schema
at com.atlassian.util.concurrent.LazyReference.getInterruptibly(LazyReference.java:149)
at com.atlassian.util.concurrent.LazyReference.get(LazyReference.java:112)
at com.atlassian.migration.agent.store.jpa.impl.DefaultSessionFactorySupplier.get(DefaultSessionFactorySupplier.java:57)
at com.atlassian.migration.agent.store.jpa.impl.DefaultSessionFactorySupplier.get(DefaultSessionFactorySupplier.java:36)
at com.atlassian.migration.agent.store.jpa.impl.DefaultPluginTransactionTemplate.on(DefaultPluginTransactionTemplate.java:31)
at com.atlassian.migration.agent.store.tx.PluginTransactionTemplate.write(PluginTransactionTemplate.java:24)
at com.atlassian.migration.agent.queue.QueueBroker.getNextBatch(QueueBroker.java:119)
at com.atlassian.migration.agent.queue.QueueBroker.dispatchBatchToConsumer(QueueBroker.java:113)
at java.util.ArrayList.forEach(Unknown Source)
at com.atlassian.migration.agent.queue.QueueBroker.runJob(QueueBroker.java:100)
at com.atlassian.confluence.impl.schedule.caesium.JobRunnerWrapper.doRunJob(JobRunnerWrapper.java:117)
at com.atlassian.confluence.impl.schedule.caesium.JobRunnerWrapper.lambda$runJob$0(JobRunnerWrapper.java:88)
at com.atlassian.confluence.impl.vcache.VCacheRequestContextManager.doInRequestContextInternal(VCacheRequestContextManager.java:87)
at com.atlassian.confluence.impl.vcache.VCacheRequestContextManager.doInRequestContext(VCacheRequestContextManager.java:71)
at com.atlassian.confluence.impl.schedule.caesium.JobRunnerWrapper.runJob(JobRunnerWrapper.java:88)
at com.atlassian.scheduler.core.JobLauncher.runJob(JobLauncher.java:134)
at com.atlassian.scheduler.core.JobLauncher.launchAndBuildResponse(JobLauncher.java:106)
at com.atlassian.scheduler.core.JobLauncher.launch(JobLauncher.java:90)
at com.atlassian.scheduler.caesium.impl.CaesiumSchedulerService.launchJob(CaesiumSchedulerService.java:443)
at com.atlassian.scheduler.caesium.impl.CaesiumSchedulerService.executeLocalJob(CaesiumSchedulerService.java:410)
at com.atlassian.scheduler.caesium.impl.CaesiumSchedulerService.executeQueuedJob(CaesiumSchedulerService.java:388)
at com.atlassian.scheduler.caesium.impl.CaesiumSchedulerService$1.consume(CaesiumSchedulerService.java:285)
at com.atlassian.scheduler.caesium.impl.CaesiumSchedulerService$1.consume(CaesiumSchedulerService.java:282)
at com.atlassian.scheduler.caesium.impl.SchedulerQueueWorker.executeJob(SchedulerQueueWorker.java:65)
at com.atlassian.scheduler.caesium.impl.SchedulerQueueWorker.executeNextJob(SchedulerQueueWorker.java:59)
at com.atlassian.scheduler.caesium.impl.SchedulerQueueWorker.run(SchedulerQueueWorker.java:34)
at java.lang.Thread.run(Unknown Source)
Caused by: javax.persistence.PersistenceException: Failed to update database schema
at com.atlassian.migration.agent.store.jpa.impl.LiquibaseSchemaUpgrader.upgrade(LiquibaseSchemaUpgrader.java:35)
at com.atlassian.migration.agent.store.jpa.impl.DefaultSessionFactorySupplier.buildSessionFactory(DefaultSessionFactorySupplier.java:62)
at com.atlassian.util.concurrent.Lazy$Strong.create(Lazy.java:85)
at com.atlassian.util.concurrent.LazyReference$Sync.run(LazyReference.java:325)
at com.atlassian.util.concurrent.LazyReference.getInterruptibly(LazyReference.java:143)
at com.atlassian.util.concurrent.LazyReference.get(LazyReference.java:112)
at com.atlassian.migration.agent.store.jpa.impl.DefaultSessionFactorySupplier.get(DefaultSessionFactorySupplier.java:57)
at com.atlassian.migration.agent.store.jpa.impl.DefaultSessionFactorySupplier.get(DefaultSessionFactorySupplier.java:36)
at com.atlassian.migration.agent.store.jpa.impl.DefaultPluginTransactionTemplate.on(DefaultPluginTransactionTemplate.java:31)
at com.atlassian.migration.agent.store.tx.PluginTransactionTemplate.read(PluginTransactionTemplate.java:16)
at com.atlassian.migration.agent.service.impl.DefaultStatisticsService.calculateServerStats(DefaultStatisticsService.java:129)
at com.atlassian.migration.agent.service.impl.SingleJobExecutor.lambda$execute$0(SingleJobExecutor.java:28)
at java.util.concurrent.CompletableFuture$AsyncSupply.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
... 1 more
Caused by: liquibase.exception.LockException: Could not acquire change log lock. Currently locked by 6be609b3a477 (172.18.0.2) since 3/30/19 4:56 PM
at liquibase.lockservice.StandardLockService.waitForLock(StandardLockService.java:230)
at liquibase.Liquibase.update(Liquibase.java:184)
at liquibase.Liquibase.update(Liquibase.java:179)
at com.atlassian.migration.agent.store.jpa.impl.LiquibaseSchemaUpgrader.upgrade(LiquibaseSchemaUpgrader.java:30)
... 15 more
```


Answers:
author: Joacim J
body: Cleared a lock in **mig_db_changelog_lock** and restarted, seems to resolved the DB lock issue.


author: Ting _Chiou Ting Teh_
body: Check this page for the query:

* [Confluence Upgrade Failed with liquibase.exception.LockException: Could not acquire change log lock Error](https://confluence.atlassian.com/confkb/confluence-upgrade-failed-with-liquibase-exception-lockexception-could-not-acquire-change-log-lock-error-969527207.html)