Backend Service unavailable

[NorDar]

For some reason the max_connections for the Postgres DB can be exhausted causing the following exception:

org.postgresql.util.PSQLException: FATAL: remaining connection slots are reserved for non-replication superuser connections
    at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2725) ~[postgresql-42.7.2.jar!/:42.7.2]
    at org.postgresql.core.v3.QueryExecutorImpl.readStartupMessages(QueryExecutorImpl.java:2837) ~[postgresql-42.7.2.jar!/:42.7.2]
    at org.postgresql.core.v3.QueryExecutorImpl.<init>(QueryExecutorImpl.java:175) ~[postgresql-42.7.2.jar!/:42.7.2]
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:317) ~[postgresql-42.7.2.jar!/:42.7.2]
    at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:54) ~[postgresql-42.7.2.jar!/:42.7.2]
    at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:273) ~[postgresql-42.7.2.jar!/:42.7.2]
    at org.postgresql.Driver.makeConnection(Driver.java:446) ~[postgresql-42.7.2.jar!/:42.7.2]
    at org.postgresql.Driver.connect(Driver.java:298) ~[postgresql-42.7.2.jar!/:42.7.2]
    at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138) ~[HikariCP-3.4.5.jar!/:na]
    at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:358) ~[HikariCP-3.4.5.jar!/:na]
    at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:206) ~[HikariCP-3.4.5.jar!/:na]
    at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:477) ~[HikariCP-3.4.5.jar!/:na]
    at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:560) ~[HikariCP-3.4.5.jar!/:na]
    at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115) ~[HikariCP-3.4.5.jar!/:na]
    at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) ~[HikariCP-3.4.5.jar!/:na]
    at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) ~[hibernate-core-5.4.32.Final.jar!/:5.4.32.Final]
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180) ~[hibernate-core-5.4.32.Final.jar!/:5.4.32.Final]
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:68) ~[hibernate-core-5.4.32.Final.jar!/:5.4.32.Final]
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35) ~[hibernate-core-5.4.32.Final.jar!/:5.4.32.Final]

[NorDar]

https://stackoverflow.com/questions/51084907/how-to-increase-the-connection-limit-for-the-google-cloud-sql-postgres-database

Edit Config Add Database flag

Add and Restart Database

[NorDar]

Or tune Hikari config via application.properties: https://github.com/brettwooldridge/HikariCP

for example idleTimeout which is 10 min by default