com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed

by

As @swanliu pointed out it is due to a bad connection.
However before adjusting the server timing and client timeout , I would first try and use a better connection pooling strategy.

Connection Pooling

Hibernate itself admits that its connection pooling strategy is minimal

Hibernate’s own connection pooling algorithm is, however, quite
rudimentary. It is intended to help you get started and is not
intended for use in a production system, or even for performance
testing. You should use a third party pool for best performance and
stability. Just replace the hibernate.connection.pool_size property
with connection pool specific settings. This will turn off Hibernate’s
internal pool. For example, you might like to use c3p0.

As stated in Reference : http://docs.jboss.org/hibernate/core/3.3/reference/en/html/session-configuration.html

I personally use C3P0. however there are other alternatives available including DBCP.
Check out

Below is a minimal configuration of C3P0 used in my application:

<property name="connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>
<property name="c3p0.acquire_increment">1</property> 
<property name="c3p0.idle_test_period">100</property> <!-- seconds --> 
<property name="c3p0.max_size">100</property> 
<property name="c3p0.max_statements">0</property> 
<property name="c3p0.min_size">10</property> 
<property name="c3p0.timeout">1800</property> <!-- seconds -->

By default, pools will never expire Connections. If you wish
Connections to be expired over time in order to maintain “freshness”,
set maxIdleTime and/or maxConnectionAge. maxIdleTime defines how many
seconds a Connection should be permitted to go unused before being
culled from the pool. maxConnectionAge forces the pool to cull any
Connections that were acquired from the database more than the set
number of seconds in the past.

As stated in Reference : http://www.mchange.com/projects/c3p0/index.html#managing_pool_size

Edit:
I updated the configuration file (Reference), as I had just copy pasted the one for my project earlier.
The timeout should ideally solve the problem, If that doesn’t work for you there is an expensive solution which I think you could have a look at:

Create a file “c3p0.properties” which must be in the root of the classpath (i.e. no way to override it for particular parts of the application). (Reference)

# c3p0.properties
c3p0.testConnectionOnCheckout=true

With this configuration each connection is tested before being used. It however might affect the performance of the site.

More Related Contents:

  1. Hibernate 5 :- org.hibernate.MappingException: Unknown entity
  2. Using Hibernate’s ScrollableResults to slowly read 90 million records
  3. The server time zone value ‘AEST’ is unrecognized or represents more than one time zone
  4. Unable to get spring boot to automatically create database schema
  5. Hibernate: Automatically creating/updating the db tables based on entity classes
  6. No Dialect mapping for JDBC type: 1111
  7. @GeneratedValue polymorphic abstract superclass over MySQL
  8. Spring boot JPA insert in TABLE with uppercase name with Hibernate
  9. Can Hibernate work with MySQL’s “ON DUPLICATE KEY UPDATE” syntax?
  10. Spring, Hibernate, Blob lazy loading
  11. How can I use MySQL assign operator(:=) in hibernate native query?
  12. Enum in Hibernate, persisting as an enum
  13. When are connections returned to the connection pool with Spring JPA (Hibernate) Entity Manager?
  14. Hibernate Criteria Query to get specific columns
  15. SQL Error: 0, SQLState: 08S01 Communications link failure [duplicate]
  16. Invalid syntax error “type= MyISAM” in DDL generated by Hibernate
  17. Hibernate: Create Mysql InnoDB tables instead of MyISAM
  18. No matter what, I can’t batch MySQL INSERT statements in Hibernate
  19. com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source
  20. org.hibernate.InstantiationException: No default constructor for entity: : principal.Cliente
  21. Is there a more efficient way of making pagination in Hibernate than executing select and count queries?
  22. How to setup Hibernate to read/write to different datasources?
  23. Hibernate Criteria API: get n random rows
  24. Unable to get multiple Table entities through Stored procedure using hibernate
  25. Make hibernate backquote all table / column names
  26. Bypass GeneratedValue in Hibernate (merge data not in db?)
  27. How does the FetchMode work in Spring Data JPA
  28. Location of hibernate.cfg.xml in project?
  29. HQL joined query to eager fetch a large number of relationships
  30. getting result set into DTO with native SQL Query in Hibernate

Leave a Comment