Infinispan cluster with Karaf instances - apache-karaf

Question

we are very new to Infinispan and also quite new to Apache Karaf. Installing Infinispan in Karaf was easy, we did write two OSGi Bundles to form a cluster with two nodes that run on one host. We tried it with the tutorial for a distributed cache from the Infinispan website (tutorial). Unfortunately the cluster seems not to be build and we can't determine why. Any help or push in the right direction would be very appreciated.
The code of the bundle that writes something in the cache looks like that:
import org.infinispan.Cache;
import org.infinispan.configuration.cache.CacheMode;
import org.infinispan.configuration.cache.ConfigurationBuilder;
import org.infinispan.configuration.global.GlobalConfigurationBuilder;
import org.infinispan.manager.DefaultCacheManager;
import org.infinispan.context.Flag;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class CacheProducer implements BundleActivator{
private static Logger LOG = LoggerFactory.getLogger(CacheProducer.class );
private static DefaultCacheManager cacheManager;
#Override
public void start( BundleContext context ) throws Exception{
LOG.info( "Start Producer" );
GlobalConfigurationBuilder global = GlobalConfigurationBuilder.defaultClusteredBuilder();
global.transport().clusterName("ClusterTest");
// Make the default cache a distributed synchronous one
ConfigurationBuilder builder = new ConfigurationBuilder();
builder.clustering().cacheMode(CacheMode.DIST_SYNC);
// Initialize the cache manager
cacheManager = new DefaultCacheManager(global.build(), builder.build());
// Obtain the default cache
Cache<String, String> cache = cacheManager.getCache();
cache.put( "message", "Hello World!" );
LOG.info( "Producer: whole cluster content!" );
cache.entrySet().forEach(entry -> LOG.info(entry.getKey()+ ": " + entry.getValue()));
LOG.info( "Producer: current cache content!" );
cache.getAdvancedCache().withFlags(Flag.SKIP_REMOTE_LOOKUP)
.entrySet().forEach(entry -> LOG.info(entry.getKey()+ ": " + entry.getValue()));
}
#Override
public void stop( BundleContext context ) throws Exception{
cacheManager.stop();
}
}
And the one that tries to print out what is in the cache like that:
package metdoc81.listener;
import org.infinispan.configuration.cache.CacheMode;
import org.infinispan.configuration.cache.ConfigurationBuilder;
import org.infinispan.configuration.global.GlobalConfigurationBuilder;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.infinispan.Cache;
import org.infinispan.manager.DefaultCacheManager;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class Activator implements BundleActivator{
private static Logger LOG = LoggerFactory.getLogger(Activator.class);
private static DefaultCacheManager cacheManager;
public void start( BundleContext bundleContext ) throws Exception{
LOG.info("start cluster listener");
GlobalConfigurationBuilder global = GlobalConfigurationBuilder.defaultClusteredBuilder();
global.transport().clusterName("ClusterTest");
// Make the default cache a distributed synchronous one
ConfigurationBuilder builder = new ConfigurationBuilder();
builder.clustering().cacheMode(CacheMode.DIST_SYNC);
// Initialize the cache manager
cacheManager = new DefaultCacheManager(global.build(), builder.build());
// Obtain the default cache
Cache<String, String> cache = cacheManager.getCache();
LOG.info("After configuration");
cache.entrySet().forEach(entry -> LOG.info(entry.getKey()+ ": " + entry.getValue()));
LOG.info("After logging");
}
public void stop( BundleContext bundleContext ) throws Exception{
}
}
The printing from the CacheProducer works, printing from the Listener does not.

Answer 1

We found the solution ourselves.
The problem just occurs when you try to run the code on MacOS, on Windows it's working. According to a discussion at JBossDeveloper there was a problem with the multicast routing on MacOS. Even though they added a workaround into the example code, you still have to add the -Djava.net.preferIPv4Stack=true Flag when running it or you have to add these two lines of code:
Properties properties = System.getProperties();
properties.setProperty( "java.net.preferIPv4Stack", "true" );