Losing database connection overnight

[unknown-user]

I have installed Alfresco Community 5.0.d on RedHat 6.5, with PostgreSql.
I have found that when I leave the server running overnight, the next day I
have database connection errors in the log, such as:

2015-09-22 21:44:07,809  ERROR [impl.jobexecutor.AcquireJobsRunnableImpl] [Thread-55] exception during job acquisition: Could not open Hibernate Session for transaction; nested exception is org.hibernate.exception.JDBCConnectionException: Cannot open connection
org.springframework.transaction.CannotCreateTransactionException: Could not open Hibernate Session for transaction; nested exception is org.hibernate.exception.JDBCConnectionException: Cannot open connection
        at org.springframework.orm.hibernate3.HibernateTransactionManager.doBegin(HibernateTransactionManager.java:597)
        at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:372)
        at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:128)
        at org.activiti.spring.SpringTransactionInterceptor.execute(SpringTransactionInterceptor.java:45)
        at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:31)
        at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:40)
        at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:35)
        at org.activiti.engine.impl.jobexecutor.AcquireJobsRunnableImpl.run(AcquireJobsRunnableImpl.java:54)
        at java.lang.Thread.run(Thread.java:745)
Caused by: org.hibernate.exception.JDBCConnectionException: Cannot open connection
        at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:74)
        at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
        at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:29)
        at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:426)
        at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:144)
        at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:119)
        at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:57)
        at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1326)
        at org.springframework.orm.hibernate3.HibernateTransactionManager.doBegin(HibernateTransactionManager.java:556)
        … 8 more
Caused by: org.postgresql.util.PSQLException: Connection refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.
        at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:215)
        at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:64)
        at org.postgresql.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.java:144)
        at org.postgresql.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.java:29)
        at org.postgresql.jdbc3g.AbstractJdbc3gConnection.<init>(AbstractJdbc3gConnection.java:21)
        at org.postgresql.jdbc4.AbstractJdbc4Connection.<init>(AbstractJdbc4Connection.java:31)
        at org.postgresql.jdbc4.Jdbc4Connection.<init>(Jdbc4Connection.java:24)
        at org.postgresql.Driver.makeConnection(Driver.java:410)
        at org.postgresql.Driver.connect(Driver.java:280)

Here are the database settings from alfresco-global.properties:
db.driver=org.postgresql.Driver
db.username=alfresco
db.password=alfresco
db.name=alfresco
db.url=jdbcostgresql://localhost:5432/${db.name}
db.pool.max=275
db.pool.validate.query=SELECT 1

[mrogers]

That's not normal.  

Something is shutting down your database or stopping alfresco talking to it. 

It could be linux killing your database due to resource starvation or a networking problem e.g a router getting switched off overnight or a machine shutting down for backup.  

[bobalfresco]

This also happened to me.
I was starting Alfresco (alfresco.sh start) from a script. The script displayed a menu of options for Alfresco (start, stop, apply amps)
and ran continuously in a loop.
I found that when I shutdown the script, I got those same type errors in the log.
When I run alfresco.start from the command line, it works correctly.

[mrogers]

There is no difference whether you invoke a command directly or through a script unless your script changes userid or something like that.   The problem is elsewhere.