Hibernate could not extract ResultSet exception
Solution 1
j.s pointed me in the right direction but didn't solve my problem.
So based on the answer given by j.s I changed my hibernate configuration to:
<!-- Database connection settings -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://server:3306/db?autoReconnect=true</property>
<property name="connection.username">user</property>
<property name="connection.password">password</property>
<!-- C3P0 connection pool -->
<property name="hibernate.c3p0.timeout">600</property>
<property name="hibernate.c3p0.maxIdleTimeExcessConnections">20</property>
<!-- Connection testing settings -->
<property name="hibernate.c3p0.validate">false</property>
<property name="hibernate.c3p0.idle_test_period">30</property>
<property name="hibernate.c3p0.automaticTestTable">conTestTable</property>
<!-- SQL dialect -->
<property name="dialect">com.ohapp.webtattoon.server.service.Mysql5BitBooleanDialect</property>
<!-- Enable Hibernate's automatic session context management -->
<property name="current_session_context_class">thread</property>
<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<!-- Echo all executed SQL to stdout -->
<property name="show_sql">false</property>
<!-- Drop and re-create the database schema on startup -->
<property name="hbm2ddl.auto">validate</property>
The key difference is the properties "hibernate.c3p0.idle_test_period" and "hibernate.c3p0.automaticTestTable". A setup that ensures that the connections in my pool are still valid preventing errors from using dead connections.
Solution 2
Looks like the configuration of the connection pool is incomplete. The timeout of connections is set to 300s.
<property name="hibernate.c3p0.timeout">300</property>
Therefore a connection can become invalid. These invalid connections are not discarded from the connection pool until you specify a rule about what to do with these connections.
By adding the following line, a connection test is performed at every connection checkout to verify that the connection is valid:
<property name="hibernate.c3p0.testConnectionOnCheckout" value="true" />
More info about connection testing: c3p0 connection testing
Edit: There is another very important property, which is not present in your config:
<property name="connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>
Without this property c3p0 is not used at all. Sry, that i didn't see that.
belyid
After a degree in management realized that it's more difficult to get the actual information than process it. So here I am learning better ways to reach the information. Acquainted with: Javascript Java C# Visual Basic HTML SQL I currently use the following frameworks: Node.js AngularJS
Updated on August 01, 2020Comments
-
belyid almost 4 years
I've deployed an GWT application on a Tomcat server. Everything is working fine but sometimes I get the following exception:
org.hibernate.exception.JDBCConnectionException: could not extract ResultSet at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:389) at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:579) at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:265) at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:305) at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62) at javax.servlet.http.HttpServlet.service(HttpServlet.java:644) at javax.servlet.http.HttpServlet.service(HttpServlet.java:725) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:301) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:503) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:136) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:74) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:526) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1017) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:652) at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1575) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1533) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:744) Caused by: org.hibernate.exception.JDBCConnectionException: could not extract ResultSet at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:132) at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49) at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125) at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110) at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:61) at org.hibernate.loader.Loader.getResultSet(Loader.java:2040) at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1837) at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1816) at org.hibernate.loader.Loader.doQuery(Loader.java:900) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:342) at org.hibernate.loader.Loader.doList(Loader.java:2526) at org.hibernate.loader.Loader.doList(Loader.java:2512)
As you can see I use Hibernate to manage my database with the following configuration:
<!-- Database connection settings --> <property name="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://server:3306/db</property> <property name="connection.username">username</property> <property name="connection.password">password</property> <!-- JDBC connection pool (use the built-in) --> <property name="hibernate.c3p0.min_size">1</property> <property name="hibernate.c3p0.max_size">15</property> <property name="hibernate.c3p0.timeout">300</property> <property name="hibernate.c3p0.max_statements">50</property> <property name="hibernate.c3p0.idle_test_period">3000</property> <!-- SQL dialect --> <property name="dialect">com.ohapp.webtattoon.server.service.Mysql5BitBooleanDialect</property> <!-- Enable Hibernate's automatic session context management --> <property name="current_session_context_class">thread</property> <!-- Disable the second-level cache --> <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property> <!-- Echo all executed SQL to stdout --> <property name="show_sql">false</property> <!-- Drop and re-create the database schema on startup --> <property name="hbm2ddl.auto">validate</property>
I don't have a clue why this happens. I would really appreciate some help.
Thank you