After doing some tests with transactions I've found transactions work not as expected after reading the documentation [1].
First of all, nowhere's written which methods of the cache are transactional and which are not. Quite the contrary, after reading documentation we get know that each TRANSACTIONAL cache is fully ACID-compliant without exceptions. Only after deep multi-thread testing, and consulting with other developers, I get know that only get and put methods are running within transaction, but iterator and query methods are running outside (in autonomous) transaction with READ_COMMITTED isolation level. Later I've understood that only methods throwing TransactionTimeoutException/TransactionRollbackException/TransactionHeuristicException are fully transactional. I think all methods on page [2] should be directly described - are they transactional or not. Btw, why these exceptions are not derived from the common base class, e.g. TransactionException? Secondary, using the transactional get() method inside the READ_COMMITTED transaction we expect to get the committed value, as the documentation [1] claims: * READ_COMMITTED - Data is read without a lock and is never cached in the transaction itself. Ok, but what about put()? After doing the put() a new value, we get successive reads of the new value, that is actually DIRTY READ. Hence the value is cached within transaction. It's not documented behavior. [1] https://apacheignite.readme.io/docs/transactions [2] https://ignite.apache.org/releases/1.8.0/javadoc/org/apache/ignite/IgniteCache.html -- Thanks, Alexandr Kuramshin
