Put() with expiration parameter not supported during transaction?

Question

Hello,
I am facing a "UnsupportedOperationException" exception when trying to put an object into a cache with an expiration parameter. The cache is obtained from a CacheAdapter inside a transaction. If I use the cache without the CacheAdapter, it works fine. Does it mean that cache used inside transaction don't support the expiration parameter or am I doing something wrong?
Here is the code that I'm using the get the cache from the CacheAdapter:
adapter = new CacheAdapter(env.getInitialContext(),
TANGOSOL_COHERENCE_RA,
CacheAdapter.CONCUR_OPTIMISTIC,
CacheAdapter.TRANSACTION_GET_COMMITTED, 0);
NamedCache c = adapter.getNamedCache(TANGOSOL_CACHE_NAME, getClass().getClassLoader());
c.put("foo", myObject, 100);
Here is the last lines of the exception trace:
java.lang.UnsupportedOperationException
     at com.tangosol.coherence.component.util.TransactionCache.put(TransactionCache.CDB:7)
     at com.tangosol.coherence.ra.component.connector.NamedCacheRecord.put(NamedCacheRecord.CDB:1)
Thanks for any tips.
Jean

Answer 1

Hi Jean,
You are correct; the caches used inside transaction don't support the expiration parameter. There are a number of reasons we made that decision. It seems that in general, the concepts of automatic eviction do not co-exist well with transactional guarantees. Consider the following scenario:
You start a transaction and put a new item with expiry of one second. One second later you are about to commit and the item has to be expired. What should the cache behavior be? Should we rollback the transaction? Or should we proceed and pretend that the item has never existed?
Similar question arise with size-limited caches and REPEATABLE_GET isolation level. What should happen if your commit forces out the entries that were read and relied on by your transaction due to a size limit?
Sorry if I had more questions than answers :-)
Regards,
Gene