我使用了postgresql 9.3和liferay 5.2
系统工作正常，但一段时间后，我在日志文件中遇到了连接丢失问题。
(org.springframework.scheduling.quartz.SchedulerFactoryBean#6e2243fb_Worker-2) 07:19:09,914 ERROR [JobWrapper:81] com.liferay.portal.kernel.job.JobExecutionException: org.postgresql.util.PSQLException: An I/O error occurred while sending to the backend.
com.liferay.portal.kernel.job.JobExecutionException: org.postgresql.util.PSQLException: An I/O error occurred while sending to the backend.
at com.liferay.counter.service.persistence.ConnectionHeartbeatJob.execute(ConnectionHeartbeatJob.java:55)
at com.liferay.portal.job.JobWrapper.execute(JobWrapper.java:69)
at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:529)
Caused by: org.postgresql.util.PSQLException: An I/O error occurred while sending to the backend.
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:226)
at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:424)
at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:321)
at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:313)
at com.mchange.v2.c3p0.impl.NewProxyStatement.execute(NewProxyStatement.java:1006)
at com.liferay.counter.service.persistence.ConnectionHeartbeatJob.sendHeartbeat(ConnectionHeartbeatJob.java:75)
at com.liferay.counter.service.persistence.ConnectionHeartbeatJob.execute(ConnectionHeartbeatJob.java:52)
... 3 more
Caused by: java.net.SocketException: Connection reset
at java.net.SocketInputStream.read(SocketInputStream.java:168)
at org.postgresql.core.VisibleBufferedInputStream.readMore(VisibleBufferedInputStream.java:143)
at org.postgresql.core.VisibleBufferedInputStream.ensureBytes(VisibleBufferedInputStream.java:112)
at org.postgresql.core.VisibleBufferedInputStream.read(VisibleBufferedInputStream.java:70)
at org.postgresql.core.PGStream.ReceiveChar(PGStream.java:283)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1799)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:200)
... 9 more
2017-08-13 08:19:09,901 INFO [STDOUT] (org.springframework.scheduling.quartz.SchedulerFactoryBean#6e2243fb_Worker-1) 08:19:09,901 WARN [NewPooledConnection:486] [c3p0] A PooledConnection that has already signalled a Connection error is still in use!
2017-08-13 08:19:09,903 INFO [STDOUT] (org.springframework.scheduling.quartz.SchedulerFactoryBean#6e2243fb_Worker-1) 08:19:09,902 WARN [NewPooledConnection:487] [c3p0] Another error has occurred [ org.postgresql.util.PSQLException: This connection has been closed. ] which will not be reported to listeners!
org.postgresql.util.PSQLException: This connection has been closed.
at org.postgresql.jdbc.PgConnection.checkClosed(PgConnection.java:786)
at org.postgresql.jdbc.PgConnection.createStatement(PgConnection.java:1598)
at org.postgresql.jdbc.PgConnection.createStatement(PgConnection.java:405)
at com.mchange.v2.c3p0.impl.NewProxyConnection.createStatement(NewProxyConnection.java:96)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.jdbc.datasource.LazyConnectionDataSourceProxy$LazyConnectionInvocationHandler.invoke(LazyConnectionDataSourceProxy.java:364)
at com.sun.proxy.$Proxy261.createStatement(Unknown Source)
at com.liferay.counter.service.persistence.ConnectionHeartbeatJob.sendHeartbeat(ConnectionHeartbeatJob.java:73)
at com.liferay.counter.service.persistence.ConnectionHeartbeatJob.execute(ConnectionHeartbeatJob.java:52)
at com.liferay.portal.job.JobWrapper.execute(JobWrapper.java:69)
at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:529)
2017-08-13 08:19:09,905 INFO [STDOUT] (org.springframework.scheduling.quartz.SchedulerFactoryBean#6e2243fb_Worker-1) 08:19:09,903 ERROR [JobWrapper:81] com.liferay.portal.kernel.job.JobExecutionException: org.postgresql.util.PSQLException: This connection has been closed.
com.liferay.portal.kernel.job.JobExecutionException: org.postgresql.util.PSQLException: This connection has been closed.
at com.liferay.counter.service.persistence.ConnectionHeartbeatJob.execute(ConnectionHeartbeatJob.java:55)
at com.liferay.portal.job.JobWrapper.execute(JobWrapper.java:69)
at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:529)
Caused by: org.postgresql.util.PSQLException: This connection has been closed.
at org.postgresql.jdbc.PgConnection.checkClosed(PgConnection.java:786)
at org.postgresql.jdbc.PgConnection.createStatement(PgConnection.java:1598)
at org.postgresql.jdbc.PgConnection.createStatement(PgConnection.java:405)
at com.mchange.v2.c3p0.impl.NewProxyConnection.createStatement(NewProxyConnection.java:96)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.jdbc.datasource.LazyConnectionDataSourceProxy$LazyConnectionInvocationHandler.invoke(LazyConnectionDataSourceProxy.java:364)
at com.sun.proxy.$Proxy261.createStatement(Unknown Source)
at com.liferay.counter.service.persistence.ConnectionHeartbeatJob.sendHeartbeat(ConnectionHeartbeatJob.java:73)
at com.liferay.counter.service.persistence.ConnectionHeartbeatJob.execute(ConnectionHeartbeatJob.java:52)
... 3 more
这是我在门户扩展属性中的配置：
#
# PostgreSQL
#
jdbc.default.driverClassName=org.postgresql.Driver
jdbc.default.url=jdbc:postgresql://192.168.2.3:5432/portal
jdbc.default.username=postgres
jdbc.default.password=postgres
我尝试添加这些行，但错误仍然出现：
jdbc.default.testConnectionOnCheckout=true
jdbc.default.preferredTestQuery=SELECT 1
jdbc.default.acquireIncrement=1
jdbc.default.maxIdleTime=10800
jdbc.default.maxConnectionAge=14400
jdbc.default.numHelperThreads=20
我无法理解错误， 在 postgresql 设置或 liferay 中的连接池设置中可能存在问题
我在postgresql.conf中有这一行，可以更改以解决此问题：
#synchronous_standby_names = '' # standby servers that provide sync rep
# comma-separated list of application_name
# from standby(s); '*' = all
更新：
此错误在日志文件中显示多次，但第一次出现是在几分钟后可能需要 1 小时。
我在docker容器中运行Postgresql。
Liferay和数据库容器位于同一物理服务器中。
我不知道为什么数据库连接在某些时候无法访问。
这是码头工人版本：
docker version
Client:
Version: 17.06.0-ce
API version: 1.30
Go version: go1.8.3
Git commit: 02c1d87
Built: Fri Jun 10 21:20:36 2017
OS/Arch: linux/amd64
Server:
Version: 17.06.0-ce
API version: 1.30 (minimum version 1.12)
Go version: go1.8.3
Git commit: 02c1d87
Built: Fri Jun 10 21:21:56 2017
OS/Arch: linux/amd64
Experimental: false
哇，Liferay 5.2？已经有一段时间了...
第一个问题是：这是否经常/每次出现？你能复制它还是只是一次？发生这种情况的一个常见原因是，当Postgresql更新并重新启动时。如果在事务期间发生这种情况，我希望Postgresql能够优雅地关闭，例如在关闭之前完成事务。
另一方面，在它再次启动之前，它将在一段时间内无法访问。即使Liferay(或连接池(确定当前连接无效(请参阅testQuery(，在服务器关闭期间也无法重新连接。如果Postgresql运行在与Liferay运行服务器不同的服务器上，它不仅可以重新启动数据库本身，还可能是完全的操作系统重新启动。当然，Liferay在此期间将失去连接。
由于您没有对重现步骤给出任何其他指示，因此我会说这是一个很好的开始猜测。否则需要更多信息。