Wednesday, 02 May 2018
We have two releases to announce:
Next is 9.3.0.Alpha1 which is the first iteration of our next release. The main item here, aside from bugfixes and preparation work for upcoming features, is the upgrade of our server component to WildFly 12.
Go and get them on our download page
Tags: release final alpha hibernate second level cache provider
Thursday, 01 October 2015
Infinispan has been implementing Hibernate Second Level Cache for a long time, replacing the previous JBoss Cache implementation with very similar logic. The main aim of the implementation has always been to have very fast reads, keeping the overhead of cache during reads on minimum. This was achieved using local reads in invalidation-mode cache and Infinispan’s putForExternalRead operation, where the request to cache never blocks.
Recently we’ve looked on the implementation again to see whether we can speed it up even more. For a long time you could use only transactional caches to keep the cache in sync with database. However transactions come at some cost so we thought about a way to get around it. And we have found it, through custom interceptors we have managed to do two-phase updates to the cache and now the non-transactional caches are the default configuration. So, if you’re using Hibernate with your own configuration, don’t forget to update that when migrating to Hibernate ORM 5!
With transactions gone, our task was not over. So far entity/collection caching has been implemented for invalidation mode caches, but it’s tempting to consider replication mode, too. For replicated caches, we got rid of a special cache for pending puts (this local cache detects out-of-date reads, keeping the entity cache consistent). Instead, we used different technique where a logical removal from the cache is substituted by replace with a token called tombstone, and updates pre-invalidate the cache in a similar way. This change opened the possibility for non-transactional replicated and distributed caches (transactional mode is not supported). We were pleased to see the results of some benchmark where the high hit ratio in replicated caches has dramatically speeded up all operations.
There is one downside of the current implementation - in replication mode, you should not use eviction, as eviction cannot tell regular entity (which can be evicted) from the tombstone. If tombstone was evicted, there’s a risk of inconsistent reads. So when using replicated caches, you should rely on expiration to keep your cache slender. We hope that eventually we’ll remove this limitation.
All modes described above give us cache without any stale reads. That comes at a cost - each modification (insert, update or removal) requires 2 accesses to the cache (though, sometimes the second access can be asynchronous). Some applications do not require such strict consistency - and that’s where nonstrict-read-write comes to the scene. Here we guarantee that the cache will provide the same result as DB after the modifying transaction commits - between DB commit and transaction commit a stale value can be provided. If you use asynchronous cache, this may be delayed even more but unless the operation fails (e.g. due to locking timeout) the cache will eventually get into a state consistent with DB. This allows us to limit modifications to single cache access per modification.
Note that nonstrict-read-write mode is supported only for versioned entities/collections (that way we can find out which entity is actually newer). Also, you cannot use eviction in nonstrict-read-write mode, for the same reason as in tombstone-based modes. Invalidation cache mode is not supported neither.
If you’ll try out the most recent Hibernate ORM, you’ll find out that Infinispan 7.2.x is used there. This is because ORM 5.0.0.Final was released before Infinispan 8.0.0.Final went out and we can’t change the major version of dependency in micro-release. However, we try to keep Infinispan 8.0.x binary compatible (in parts used by Hibernate), and therefore you can just replace the dependencies on classpath and use the most recent Infinispan, if you prefer to do so.
To sum things up, here is the table of supported configurations:
There’s also the read-only mode - this can be used instead of both transactional or read-write modes, but at this point it does not offer any further performance gains, since we have to make sure that you don’t see a removed value. Actually, it also does not matter whether you specify transactional or read-write mode; the proper strategy will be picked according to your cache configuration (transactional vs. non-transactional).
We hope that you’ll try these new modes and many consistency fixes included along (you should use Hibernate ORM 5.0.2.Final or later), and tell us about your experience.
Tags: jpa hibernate second level cache provider
Friday, 03 May 2013
The first ever JUDCon Brazil was held a couple of weeks back and it was a real blast! Firstly, it offered a great opportunity to meet some members of the JBoss community which have been helping us push JBoss projects forward in this region of the world, such as Hanneli Tavante, Roberto dos Santos Wagner, …etc. It was great sharing ideas, experiences…etc with them and coming up with new ideas!
As mentioned before in the post before the conference, I had two new presentations to deliver, one on JSR-107 specification on JCache API and Infinispan’s implementation, and the other on Hibernate Second Level Cache with Infinispan. The JCache presentation went really well and all the live coding worked as expected.
The second presentation was the busier of the two, with a full room packed with Hibernate/JPA users waiting to hear how to scale up their applications. I got excellent feedback from both presentations and looking forward to giving these presentations in more user groups or conferences.
The presentations are not up yet, but I expect them to be posted online in the next few weeks. In the mean time, here are a couple of temporary links to the PDFs of my presentations:
The big news of the conference was for sure the announcement of JBoss Application Servers' new name: WildFly. We’re actively working with them to make the most out of Infinispan :)
Tags: conference presentations event jsr 107 judcon hibernate second level cache provider
Tuesday, 07 June 2011
Starting with Hibernate 4.0.0.Beta1, Infinispan second level cache interacts with the transaction manager as a JTA Synchronization instead of an XA resource. Based on some testing we’ve done in JBoss AS 7, this has resulted in a huge performance increase thanks to the optimisations the transaction manager can apply to Synchronizations, which work very well when Infinispan is used as a cache rather than as a authoritative data store.
From an Infinispan configuration perspective, nothing needs changing. The Infinispan provider still uses the same base configuration by default. Transactional configuration happens within the cache provider itself and it’s here where the Infinispan is configured with Hibernate’s transaction manager and where Infinispan is configured to participate as a JTA synchronization. This is the default configuration, so from an user perspective, there’s nothing you have to do to take advantage of this new change.
However, you can always switch back to previous behaviour where Infinispan interacted as an XA resource via a dedicated Hibernate property called hibernate.cache.infinispan.use_synchronization
By default this property is set to true. If you set it false, Infinispan will interact with the transaction manager as an XA resource.
For more detailed information, check the "http://community.jboss.org/docs/DOC-14105[Using Infinispan As JPA Hibernate Second Level Cache Provider]" wiki.
Tags: transactions jpa synchronization hibernate second level cache provider
Wednesday, 01 December 2010
While Infinispan can be used as a Hibernate second level cache with Hibernate 3.5 onwards, Bill deCoste has written a guide to getting Infinispan to work in older versions of Hibernate, specifically with JBoss AS 5.x. Hope you find this useful!
Tags: jboss as 5 as5 hibernate second level cache provider
Tuesday, 02 February 2010
While Infinispan has got the distributed, in-memory data grid market firmly it in its sight, there is also another aspect of Infinispan which I feel people would find interesting.
At its heart Infinispan is a highly concurrent, extremely performant data structure than can be distributed, or could be used in a standalone, local mode - as a cache. But why would people use Infinispan over, say, a ConcurrentHashMap? Here are some reasons.
Eviction. Built-in eviction ensures you don’t run out of memory.
Write-through and write-behind caching. Going beyond memory and onto disk (or any other pluggable CacheStore) means that your state survives restarts, and preloaded hot caches can be configured.
JTA support and XA compliance. Participate in ongoing transactions with any JTA-compliant transaction manager.
MVCC-based concurrency. Highly optimized for fast, non-blocking readers.
Cluster-ready. Should the need arise.
*Easy to configure, easy to use*
The simplest configuration file containing just
is enough to get you started, with sensible defaults abound. (More detailed documentation is also available).
All the features above are exposed via an easy-to-use Cache interface, which extends ConcurrentMap and is compatible with many other cache systems. Infinispan even ships with migration tools to help you move off other cache solutions onto Infinispan, whether you need a cache to store data retrieved remotely or simply as a 2nd level cache for Hibernate.
In the process of testing and tuning Infinispan on very large clusters, we have started to put together a benchmarking framework. As a part of this framework, we have the ability to measure cache performance in standalone, local mode. So in the context of this blog post, I’d
like to share some recent performance numbers of Infinispan - a recent snapshot - compared against the latest JBoss Cache release (3.2.2.GA) and EHCache (1.7.2). Some background on the tests:
Used a latest snapshot of the CacheBenchFwk
Run on a RHEL 5 server with 4 Intel Xeon cores, 4GB of RAM
Sun JDK 1.6.0_18, with -Xms1g -Xmx1g
Test run on a single node, with 25 concurrent threads, using randomly generated Strings as keys and values and a 1kb payload for each entry, with a 80/20 read/write ratio.
Performance measured in transactions per second (higher = better).
In summary, what we have here is that when run in local mode, Infinispan is a high-performance standalone caching engine which offers a rich set of features while still being trivially simple to configure and use.
Tags: benchmarks jboss cache hibernate local mode second level cache provider ehcache
Tuesday, 20 October 2009
Update (2009/11/13)! Infinispan 4.0.0.Beta2 based Hibernate second level cache provider now available in Hibernate 3.5 Beta2. However, neither Infinispan 4.0.0.Beta2 nor the Infinispan Cache Provider jar are available in the zip distribution. Instead, please download Infinispan 4.0.0.Beta2 from our download site and the Infinispan Cache Provider from our Maven repository.
I’ve just finished the development of an Infinispan 4.0 based Hibernate second level cache provider. This will be included from next Hibernate 3.5 release onwards but if you cannot wait and wanna play with it in the mean time, just checkout Hibernate trunk from our SVN repository and run 'mvn install'.
I’ve also written a wiki called "Using Infinispan as JPA/Hibernate Second Level Cache Provider" that should help users understand how to configure the Infinispan cache provider and how to make the most of it!
So, what’s good about it? Why should I use it? First of all, since the cache provider is based on Infinispan, you benefit from all the improvements we’ve done to Infinispan in terms of performance and memory consumption so far and there are more to come!
On top of that, starting with this cache provider, we’re aiming to reduce the number of files needed to modify in order to define the most commonly tweaked parameters. So, for example, by enabling eviction/expiration configuration on a per generic Hibernate data type or particular entity/collection type via hibernate.cfg.xml or persistence.xml, users don’t have to touch to Infinispan’s cache configuration file any more. You can find detailed information on how to do this in the "Using Infinispan as JPA/Hibernate Second Level Cache Provider" wiki
Please direct any feedback to the Infinispan user forum.
Tags: eviction hibernate second level cache provider