The Bitronix Transaction Manager (BTM) is a simple but complete implementation of the JTA 1.1 API. It is a fully working XA transaction manager that provides all services required by the JTA API while trying to keep the code as simple as possible for easier understanding of the XA semantics.
The BTM 3.0 release has two primary goals: performance improvements, and code modernization. The codebase was moved from
a Java 1.4 codebase to Java 5, taking advantage of generics for type-safety and java.util.concurrent classes for improved
performance. Notable improvements are:
- Greater use of low-contention lock collections throughout the code and the removal of most large-grained locks.
- A new connection pool with a focus on zero-wait connection acquisition and concurrent expansion/contraction. For one large workload compared to BTM 2.1 total connection wait time went from 76 seconds to 372ms, and lock contentions went from 26269 to just 21.
- High-performance proxies around
javax.sqlentities via bytecode generation with support for Javassist, and cglib, with fallback tojava.lang.reflect.proxy. Javassist and cglib offer substantial performance increases and are strongly recommended. - High-performance transaction log journaling using a new design that allows concurrent appenders through a write-reservation model. The new journal is 3-14x faster than BTM 2.1.
- Support for all levels of JDBC upto and including JDBC 4.1
- OSGi support
- A change of license from LGPL v3 to Apache 2.