Wednesday, 19 September 2012

5.2.0.Alpha4 brings cross-site replication into Infinispan!

Besides other enhancements and fixes, this release brings the first implementation of the cross-site replication functionality in Infinispan. In other words, you can now use Infinispan for backing up your data across geographically distributed sites or migrate your data where your users are (follow the sun).
More about the x-site replication functionality here.
You can download the distribution or the maven artifact. If you have any questions please check our forums, our mailing lists or ping us directly on IRC!

Cheers,
Mircea

Wednesday, 5 September 2012

Infinispan Arquillian Container 1.0.0.CR1 released

Infinispan Arquillian Container is an extension to Arquillian that provides several ways to interact with Infinispan, either with a standalone Infinispan server or just with Infinispan libraries. This extension can also communicate with JBoss Data Grid server via JMX.

It was released as Maven artifacts in JBoss Maven Repository. It is located at http://repository.jboss.org/nexus/content/groups/public-jboss/ . More information on how to set up and use the repo can be found at https://community.jboss.org/wiki/MavenGettingStarted-Users

What does this Arquillian extension offer to you? Let me describe all aspects of this extension one by one.

Developing tests with standalone Infinispan server


When testing, you might want to automatically start the Infinispan server before the test and stop it afterwards. This can be achieved by configuring infinispan-arquillian-container via Arquillian's configuration file. The following is a subset of attributes that can be specified and thus passed to the Infinispan server during startup: masterThreads, workerThreads, cacheConfig, jmxPort, ... The complete list can be found in bit.ly/R7j4d1 (all private fields).


NOTE: Examples are not a part of the release, only libraries are. In order to check out examples provided with the project, one has to clone project's repository: https://github.com/mgencur/infinispan-arquillian-container Examples are located in the respective sub-directory.

The configuration file then looks similar to the following:

Whether these two Infinispan servers are clustered or not depends on the configuration passed to them via cacheConfig (file path) attribute or their default configuration (when no config. file is passed). The configuration in arquillian.xml file just says: "Start these two instances with whatever configuration is passed to them".

Complete example: bit.ly/RkrpEE

When we tell Arquillian to work with Infinispan server, we can inject RemoteInfinispanServer object into our test. Such an object provides various information about the running Infinispan server. For example, we can retrieve a hostname and HotRod port and use these pieces of information to create a RemoteCacheManager instance. Besides that users are allowed to retrieve information available via JMX from the server like cluster size, number of entries in the cache, number of cache hits and many more.

Complete example: http://bit.ly/OaCw8q

Vital dependencies required for the test to run are:

org.infinispan.arquillian.container:infinispan-arquillian-container-managed:jar:1.0.0.CR1:test
org.infinispan.arquillian.container:infinispan-arquillian-impl:jar:1.0.0.CR1:test

Not only with standalone Infinispan server can Infinispan Arquillian extension work.

Developing tests with JBoss Data Grid (JDG) server


This time, the properties in Arquillian's configuration file are different and correspond to properties of JBoss Application Server 7. The most important property is again the path to the server (jbossHome).

Are you interested in what the test looks like? It looks completely the same as tests for standalone Infinispan server, you just have a few more attributes available. JDG server usually starts all three endpoints (HotRod, Memcached, REST) at the same time while for the Infinispan server you have to specify which end point should be started. Furthermore, Infinispan server does not have the REST endpoint available out-of-the-box.

As a result, you can call the following methods with JDG in one single test.

server1.getMemcachedEndpoint().getPort();
server1.getRESTEndpoint().getContextPath();
server1.getHotRodEndpoint().getPort();

The difference is, of course in dependencies. Instead of a handler for standalone Infinispan server, one has to use a handler for JBoss AS 7. The dependencies then look like this:

org.jboss.as:jboss-as-arquillian-container-managed:jar:7.1.2.Final:test
org.infinispan.arquillian.container:infinispan-arquillian-impl:jar:1.0.0.CR1:test


Testing Infinispan libraries


Sometimes we don't want to use a standalone server. Sometimes we want to test just Infinispan in its basic form - Java libraries. Infinispan has been under development for years and during that time, lots of tests were developed. With tests come utility methods. Infinispan Arquillian Container enables you to leverage these utility methods and call them via an instance of DatagridManager. This instance can be easily injected into a test, no matter which test framework (TestNG, JUnit) you use.

DatagridManager class can be found at http://bit.ly/Q0a7ki

Can you see the advantage? No? Let me point out some useful methods available in the manager.

List<Cache<K, V>> createClusteredCaches(int numMembersInCluster, String cacheName, ConfigurationBuilder builder)

- creates a cluster of caches with certain name and pre-defined configuration

void waitForClusterToForm()

- helps to wait until the cluster is up and running

Cache<A, B> cache(int index)

- retrieves a cache from certain node according to the index

Cache<A, B> cache(int managerIndex, String cacheName)

- retrieves a cache with that name

void killMember(int cacheIndex)

- kills a cache with cacheIndex index

AdvancedCache advancedCache(int i)

- retrieves an advanced cache from node i

Trancation tx(int i)

- retrieves a transaction from node i

TransactionManager tm(int i)

- retrieves a transaction manager from node i

...and much more.


The following test can be found among other examples in the GIT repository.

Required dependencies:

org.infinispan:infinispan-core:jar:5.1.5.FINAL:test  -  users should replace this version with the one they want to test
org.infinispan.arquillian.container:infinispan-arquillian-impl:jar:1.0.0.CR1:test

Infinispan Arquillian Container was tested with Infinispan 5.1.5.FINAL and JDG 6.0.0.GA. Nevertheless, it should work smoothly also with other not-very-distinct versions. I'll be updating the project to work with newer versions of both Infinispan and JBoss Data Grid.
 

Tuesday, 4 September 2012

Speeding up Cache calls with IGNORE_RETURN_VALUES invocation flag

Starting with Infinispan 5.2.0.Alpha3, a new Infinispan invocation flag has been added called IGNORE_RETURN_VALUES.

This flag signals that the client that calls an Infinispan Cache operation () which has some kind of return, i.e. java.util.Map#put(Object, Object) (remember that Infinispan's Cache interface extends java.util.Map), the return value (which in the case of java.util.Map#put(Object, Object) represents the previous value) will be ignored by the client application. A typical client application that ignores the return value would use code like this:

In this example, both cache put call are ignoring the return of the put call, which returns the previous value. In other words, when we cache the last login date, we don't care what the previous value was, so this is a great opportunity for the client code to be re-written in this way:

Or even better:

Thanks to such hints, Infinispan caches can behave in a more efficient way and can potentially do operations faster, because work associated with the production of the return value will be skipped. Such work can on occasions involve network calls, or access to persistent cache stores, so by avoiding this work, the cache calls are effectively faster.

In previous Infinispan versions, a similar effect could be achieved with flags with a narrower target and which are considered too brittle for end user consumption such as SKIP_REMOTE_LOOKUP or SKIP_CACHE_LOAD. So, if you're using either of these flags in your Infinispan client codebase, we highly recommend that from Infinispan 5.2.0.Alpha3 you start using IGNORE_RETURN_VALUES instead.

Cheers, Galder

Saturday, 1 September 2012

Infinispan 5.2.0.Alpha3 is out!

There are releases and releases. And this one is a big one, containing a bran new state transfer functionality. Designed and implemented by Dan Berindei and Adrian Nistor, the new Non Blocking State Transfer (NBST) has the following goals:
  • Minimize the interval(s) where the entire cluster can't respond to requests because of a state transfer in progress.
  • Minimize the interval(s) where an existing member stops responding to requests because of a state transfer in progress.
  • Allow the performance of the cluster to drop during state transfer, but it should not throw any exception
Curious to see the magic behind it?  This document is here to explain you NBST's internal.

Besides NBST this release brings some other goodies:
  • A new IGNORE_RETURN_VALUES flag to help reduce the number of RPC calls and increasing performance (to be discussed at large by Galder Zamarreño in a following blog post)  
  • A revamped and much nicer configuration for submodules such as cache loaders. More about it in  Tristan Tarrant's blog
  • for a complete list of the fixes/enhancements refer to JIRA
Another new thing this release brings is a change in versioning: we've aligned to JBoss' release versioning pattern. So the name is now Alpha3 vs ALPHA3(as per the old naming pattern). More about the reason for doing that in this blog post.
  
The complete list of issues/improvements addressed in this release is available in JIRA. As always, please give it a try and let us know what you think on the forums, irc or mailing lists!

Cheers,
Mircea