Connection leak Issue with C3p0 With Rapidclipse

Question

we created an application using RapidclipseX and using PostgreSQL as a database. Below was my initial setting of peristance.xml.

property name="hibernate.hbm2ddl.auto" value="none" />
        <property name="javax.persistence.sharedCache.mode" value="ENABLE_SELECTIVE" />
        <property name="hibernate.c3p0.max_size" value="50000" />
        <property name="hibernate.c3p0.idle_test_period" value="300" />
        <property name="hibernate.c3p0.max_statements" value="100" />
        <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQL95Dialect" />
        <property name="hibernate.cache.use_query_cache" value="true" />
        <property name="hibernate.c3p0.min_size" value="1" />
        <property name="hibernate.default_schema" value="canavans" />
        <property name="rap.queryCache.mode" value="ENABLE_SELECTIVE" />
        <property name="hibernate.archive.autodetection" value="" />
        <property name="hibernate.cache.use_second_level_cache" value="true" />
        <property name="hibernate.c3p0.timeout" value="3000" />
        <property name="hibernate.transaction.auto_close_session" value="false" />
        <property name="hibernate.javax.cache.uri" value="classpath:ehcache.xml" />
        <property name="hibernate.show_sql" value="false" />
        <property name="hibernate.cache.region.factory_class" value="org.hibernate.cache.jcache.JCacheRegionFactory" />
        <property name="javax.persistence.jdbc.driver" value="org.postgresql.Driver" />
        <property name="hibernate.generate_statistics" value="false" />
        <property name="hibernate.auto_quote_keyword" value="true" />
        <property name="hibernate.globally_quoted_identifiers" value="true" />

When we went on production, we started to get an error: " acquire test – the pool is already maxed out."

Then I added these 2 lines:

<property name="hibernate.c3p0.unreturnedConnectionTimeout" value="120" />
<property name="hibernate.c3p0.debugUnreturnedConnectionStackTraces" value="true" />

For some time, it solved our issue. But now, after we imported the old database, we started to get a new error:

2020-11-25 16:44:11 DEBUG DefaultConnectionTester:207 - Testing a Connection in response to an Exception:
org.postgresql.util.PSQLException: This connection has been closed.
        at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.handleAndClearWarnings(SqlExceptionHelper.java:299)
        at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.logAndClearWarnings(SqlExceptionHelper.java:269)
2020-11-25 16:44:11 DEBUG NewPooledConnection:207 - com.mchange.v2.c3p0.impl.NewPooledConnection@614f3f61 invalidated by Exception.

when I google for the problem, I found that: the solution for the Maxed out the problem that I've implemented (those 2 lines) can be the problem for the new exceptions.

I've also found the connection leak problem. I tried to close entityManager in DAOs, but when I add any JPA-SQL Query and load the Java file, those lines disappear.

Please help me how to solve this issue once and for all. Is there is any efficient way to do this? We have to restart our application on production again and again.

I really appreciate any help you can provide.

What do you mean by: 'I tried to close entityManager in DAOs, but when I add any JPA-SQL Query and load the Java file, those lines disappear'? — crizzis, Nov 30 '20 at 21:51
Rapidclipse has its own DAO editior, if you try to put those entityManager close code and when you save it just go away. — Prashant Kumar, Dec 01 '20 at 13:45

score 0 · Accepted Answer · answered May 15 '21 at 14:10

The Issue was with the Rapidclipse X initial framework version. This issue is solved in the Latest Framework of Rapidclipse X.0.4 in Framework 10+

XWS-1881 - Refreshing a page with multiple StreamResources caused a steady increase in pool size. We fixed this issue by adding lazy initialization for the EntityManager to the per-request session strategy. This means that the EntityManager is only created on-demand, and not on every request made to the server application. This should increase the framework performance overall

Rapidclipse Patchnotes Version 10.4.0

Connection leak Issue with C3p0 With Rapidclipse

1 Answers1