[infinispan-dev] Starting caches in parallel

[Dan Berindei]

Hi guys

I've found a deadlock with transactions spanning multiple caches
during rehashing if the joiner's caches are started sequentially (for
more details see https://gist.github.com/1124740)
After discussing a bit on IRC with Manik and Galderz it appears the
only solution for 5.0.0.FINAL would be to have a mechanism to start
all the caches in parallel.

There are several options to implement that. All of them require the
users to know that they should create the caches in parallel at
application startup to avoid problems.

1. Advise the users about the problem, but let them create their own
threads and call EmbeddedCacheManager.getCache() on those threads.


2. Add a method EmbeddedCacheManager.getCaches() to start multiple
caches in parallel.

This is not as straightforward as it may seem, first there is a
question of whether to use template parameters or not:
2.a. Set<Cache> getCaches(String... cacheNames);
vs
2.b. Set<Cache<K, V>> getCaches(String... cacheNames);

I don't think having the same K and V for all the caches is going to
be very common, so I'd go with 2.a.

Then there is the problem of how to request the default cache. I think
"" should be fine, but we'd need to document it and also change the
regular getCache() methods to accept it.


3. Add an async version of EmbeddedCacheManager.getCache():

Future<Cache<K, V>> getCacheAsync(String cacheName);
Future<Cache<K, V>> getCacheAsync();

This nicely sidesteps the generics issue in solution 2 and it's also
easier for the users than solution 1, so it's currently my favourite.


What do you think?


Dan