TransactionSynchronizationUtils.unwrapResourceIfNecessary() does not unwrap OSGi service proxies [SPR-7368]

[spring-projects-issues]

Ric Klaren opened SPR-7368 and commented

We experienced deadlocks in our product while load testing. The issue occurs when mixing Hibernate Sessions with JdbcTemplate code. What basically happens:

1. The session in view filter creates a new Hibernate Session.
2. The HibernateTransactionManager registers a JDBC datasource in the thread local map using the real class.
3. Somewhere in a service call (and transaction) the user details are requested via the JdbcUserDetailsManager (from spring security) which is implemented as a JdbcTemplate. The JdbcTemplate has a JDK proxy of the datasource. This leads to a lookup in the thread local map with the proxy in stead of the real data source. Since TransactionSynchronizationUtils.unwrapResourceIfNecessary() does not unwrap JDK proxies the lookup fails. As a result the existing connection is not reused and a new connection is requested from the connection pool.

This deadlocks when the connection pool has no connections left.

(Checked the code up to 3.0.3 Release in which this is also present)

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Affects: 3.0 GA

[spring-projects-issues]

Juergen Hoeller commented

What kind of DataSource proxy is it that your JdbcTemplate is talking to? Are you applying aspects to it by any chance?

Juergen

[spring-projects-issues]

Ric Klaren commented

It is a Spring DM imported bean from another OSGi bundle (and as such a proxy). Now I start to wonder if it can be unwrapped at all....

[spring-projects-issues]

Ric Klaren commented

It looks like its fixed by upgrading the spring framework in Spring DM Server to spring 3.0.3.

Cheers,

Ric

[spring-projects-issues]

Juergen Hoeller commented

Alright - good to hear that it works for you against 3.0.3!

This should be fixed since 3.0.1, actually, so I'm marking this as resolved for 3.0.1 now.

Juergen

[spring-projects-issues]

Ric Klaren commented

I'm afraid I was not able to test with 3.0.1 I ran into issues with spring security and the various 3.0.1 bundles (RELEASE/RELEASE-A).

Thank you for looking into it.

Cheers,

Ric