Spring boot crashes randomly without errors - spring

Question

I have a Spring boot application in version 2.1.2.RELEASE. Once a month or few weeks application crashes without any specific information in logs.
Server where app is deploy is CentOS ver 7, app is launched by a systemd service.
Tried analysing heap dump, no luck, checked logs of postgres, tomcat etc. nothing there.
Stacktrace:
INFO ;read-5;523575402;2019-08-07 17:27:24,714;o.s.i.e.EventDrivenConsumer; Removing {logging-channel-adapter:_org.springframework.integration.errorLogger} as a subscriber to the 'errorChannel' channel
INFO ;read-5;523575418;2019-08-07 17:27:24,730;o.s.i.c.PublishSubscribeChannel; Channel 'application.errorChannel' has 0 subscriber(s).
INFO ;read-5;523575418;2019-08-07 17:27:24,730;o.s.i.e.EventDrivenConsumer; stopped _org.springframework.integration.errorLogger
INFO ;read-5;523575502;2019-08-07 17:27:24,814;o.s.s.c.ThreadPoolTaskScheduler; Shutting down ExecutorService 'taskScheduler'
INFO ;read-5;523575541;2019-08-07 17:27:24,853;o.s.s.c.ThreadPoolTaskExecutor; Shutting down ExecutorService 'applicationTaskExecutor'
INFO ;read-5;523575572;2019-08-07 17:27:24,884;o.s.o.j.LocalContainerEntityManagerFactoryBean; Closing JPA EntityManagerFactory for persistence unit 'default'
INFO ;read-5;523575596;2019-08-07 17:27:24,908;c.z.h.HikariDataSource; HikariPool-1 - Shutdown initiated...
INFO ;read-5;523575631;2019-08-07 17:27:24,943;c.z.h.HikariDataSource; HikariPool-1 - Shutdown completed.
WARN ;exec-8;523575668;2019-08-07 17:27:24,980;c.z.h.p.ProxyConnection; HikariPool-1 - Connection org.postgresql.jdbc.PgConnection#6ff70ea8 marked as broken because of SQLSTATE(08006), ErrorCode(0)
org.postgresql.util.PSQLException: An I/O error occurred while sending to the backend.
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:335)
at org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:441)
at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:365)
at org.postgresql.jdbc.PgPreparedStatement.executeWithFlags(PgPreparedStatement.java:143)
at org.postgresql.jdbc.PgPreparedStatement.executeQuery(PgPreparedStatement.java:106)
at com.zaxxer.hikari.pool.ProxyPreparedStatement.executeQuery(ProxyPreparedStatement.java:52)
at com.zaxxer.hikari.pool.HikariProxyPreparedStatement.executeQuery(HikariProxyPreparedStatement.java)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:60)
at org.hibernate.loader.Loader.getResultSet(Loader.java:2173)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1936)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1898)
WARN ;exec-6;523575677;2019-08-07 17:27:24,989;c.z.h.p.ProxyConnection; HikariPool-1 - Connection org.postgresql.jdbc.PgConnection#71c6647 marked as broken because of SQLSTATE(08006), ErrorCode(0)
org.postgresql.util.PSQLException: An I/O error occurred while sending to the backend.
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:335)
at org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:441)
at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:365)
at org.postgresql.jdbc.PgPreparedStatement.executeWithFlags(PgPreparedStatement.java:143)
at org.postgresql.jdbc.PgPreparedStatement.executeQuery(PgPreparedStatement.java:106)
at com.zaxxer.hikari.pool.ProxyPreparedStatement.executeQuery(ProxyPreparedStatement.java:52)
at com.zaxxer.hikari.pool.HikariProxyPreparedStatement.executeQuery(HikariProxyPreparedStatement.java)
WARN ;exec-8;523575721;2019-08-07 17:27:25,033;o.h.e.j.s.SqlExceptionHelper; SQL Error: 0, SQLState: 08006
WARN ;exec-6;523575721;2019-08-07 17:27:25,033;o.h.e.j.s.SqlExceptionHelper; SQL Error: 0, SQLState: 08006
ERROR;exec-8;523575721;2019-08-07 17:27:25,033;o.h.e.j.s.SqlExceptionHelper; An I/O error occurred while sending to the backend.
ERROR;exec-6;523575721;2019-08-07 17:27:25,033;o.h.e.j.s.SqlExceptionHelper; An I/O error occurred while sending to the backend.
INFO ;exec-6;523575885;2019-08-07 17:27:25,197;o.h.e.i.DefaultLoadEventListener; HHH000327: Error performing load command : org.hibernate.exception.JDBCConnectionException: could not extract ResultSet
org.hibernate.exception.JDBCConnectionException: could not extract ResultSet
at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:115)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:113)
Has anyone got idea how can I what might be going on? Last crash was 3, 4 weeks before that.

Answer 1

That type of error happens when the database connection has been lost, which in turn can happen for a whole number of reasons, the most simple one being that it's being restarted after system updates or as part of a scheduled operation.
HikariCP should be able to recover according to the following link (provided that your HikariCP version is recent enough):
https://github.com/brettwooldridge/HikariCP/wiki/Rapid-Recovery
You may need to configure some properties in your pool. The full list of properties is available here:
https://github.com/brettwooldridge/HikariCP
I recommend you configure the following in HikariCP:
connectionTestQuery: will test the connection periodically, dropping dead connections. Use it in conjunction with socketTimeout in your PostgreSQL connection string
leakDetectionThreshold: will help with applications having connection leaks