Question

I have an application that is using Hibernate 3, c3p0, and spring 2.5.6. We have a datasource that is configured to speak with a postgres database. Everything was working great until a firewall was introduced between the application server and the database. We intermittently are getting java.net.SocketTimeoutException: Read Timed Out errors while trying to communicate with the database.

We believe the overhead of the firewall is causing a delayed response from the database. We want to verify this by increasing the thresh hold of how long a query should wait before deemed timed out (if that is even possible). Here is a stacktrace snippet

org.postgresql.util.PSQLException: An I/O error occured while sending to the backend.
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:218)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:451)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:350)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:254)
    at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeQuery(NewProxyPreparedStatement.java:76)
    at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:208)
    at org.hibernate.loader.Loader.getResultSet(Loader.java:1808)
    at org.hibernate.loader.Loader.doQuery(Loader.java:697)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
    at org.hibernate.loader.Loader.loadEntity(Loader.java:1881)
    ... 35 more
Caused by: java.net.SocketTimeoutException: Read timed out
    at java.net.SocketInputStream.socketRead0(Native Method)
    at java.net.SocketInputStream.read(Unknown Source)
    at org.postgresql.core.VisibleBufferedInputStream.readMore(VisibleBufferedInputStream.java:135)
    at org.postgresql.core.VisibleBufferedInputStream.ensureBytes(VisibleBufferedInputStream.java:104)
    at org.postgresql.core.VisibleBufferedInputStream.read(VisibleBufferedInputStream.java:73)
    at org.postgresql.core.PGStream.ReceiveChar(PGStream.java:259)
    at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1166)
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:192)
    ... 44 more

Answer 1

This has nothing to do with Hibernate or C3P0; you’re getting a timeout from JDBC driver.

If you’re using version 8.4 or higher, try setting socketTimeout to a higher value (or even zero for disabling it) in your connection string.