Ex­tremeTrans­ac­tions 5.0.104

Fea­ture190375

Al­low re­cy­cling of ac­tive con­nec­tions with­in the same trans­ac­tion

You can now al­low re­cy­cling of ac­tive JDBC/XA pooled con­nec­tions with­in the same trans­ac­tion, be­fore they are "closed" by the ap­pli­ca­tion. This means that cer­tain dead­lock sce­nar­ios can be avoid­ed.

Tech­ni­cal de­tails

Imag­ine the fol­low­ing use case:

1. start a JTA trans­ac­tion
2. get a JDBC/XA con­nec­tion (c1) from the pool via getCon­nec­tion()
3. do some SQL on c1
4. get a sec­ond JDBC/XA con­nec­tion (c2) from the pool via getCon­nec­tion()

Be­fore this fea­ture, step 4 would re­turn a dif­fer­ent phys­i­cal con­nec­tion from the pool. This would trig­ger a new XA branch, with un­spec­i­fied iso­la­tion (lock­ing) be­hav­iour with re­spect to any up­dates per­formed via the con­nec­tion in step 2. This could even cause dead­locks.

There­fore, peo­ple have asked us to al­low for step 4 to reuse the same con­nec­tion, c1. You can now en­able this new be­hav­iour by call­ing setRe­cy­cleAc­tiveCon­nec­tion­sInTrans­ac­tion(true) on the AtomikosDataSourceBean.

Changes im­pact­ing client API

A new, op­tion­al set­ter on our data­source. The de­fault is false for back­ward com­pat­i­bil­i­ty.

About Sever­i­ty

The sever­i­ty lev­els we use are de­fined in our sup­port terms and con­di­tions.