When the server has been running for some time I get the following error and jboss needs to be restarted:

org.jboss.util.NestedSQLException: No ManagedConnections available within configured blocking timeout ( 30000 [ms] ); - nested throwable: (javax.resource.ResourceException: No ManagedConnections available within configured blocking timeout ( 30000 [ms] ))

After a restart the connections work well again until the same error appears. How can I solve this? I have checked that all connections that are used get closed. Here is my mysql-ds.xml.

<datasources>
 <local-tx-datasource>
 <jndi-name>MySqlDS</jndi-name>
 <connection-url>jdbc:mysql://localhost:3306/market</connection-url>
 <driver-class>com.mysql.jdbc.Driver</driver-class>
 <user-name>developer</user-name>
 <password>abc123</password>
 <exception-sorter-class-name>org.jboss.resource.adapter.jdbc.vendor.MySQLExceptionSorter</exception-sorter-class-name>
 <!-- sql to call when connection is created
 <new-connection-sql>some arbitrary sql</new-connection-sql>
 -->
 <!-- sql to call on an existing pooled connection when it is obtained from pool
 <check-valid-connection-sql>some arbitrary sql</check-valid-connection-sql>
 -->

 <!-- corresponding type-mapping in the standardjbosscmp-jdbc.xml (optional) -->
 <metadata>
 <type-mapping>mySQL</type-mapping>
 </metadata>
 </local-tx-datasource>
</datasources>

Any help is appreciated.

Thanks