Runtime changes of cache config elements

[manik]

I've created a new annotation to go with org.jboss.cache.config.Configuration - @Dynamic.

This annotation is applied to fields in the Configuration class and if a setter is called on a Configuration object, if the cache is running and the field the setter modifies does not have the @Dynamic annotation a ConfigurationException is thrown.

Easy way to control configuration changes on a running cache - the only question is, which elements should be treated as dynamic? :)

Here is an initial list of the fields:

private String clusterName = "TreeCache-Group";
 private String clusterConfig = null;
 private boolean useReplQueue = false;
 @Dynamic
 private int replQueueMaxElements = 1000;
 @Dynamic
 private long replQueueInterval = 5000;
 private boolean useInterceptorMbeans = true;
 private boolean fetchInMemoryState = true;
 private short replicationVersion = DEFAULT_REPLICATION_VERSION;
 private String replVersionString = Version.getVersionString(DEFAULT_REPLICATION_VERSION);
 @Dynamic
 private long lockAcquisitionTimeout = 10000;
 @Dynamic
 private long syncReplTimeout = 15000;
 private String evictionPolicyClass = null;
 private CacheMode cacheMode = CacheMode.LOCAL;
 private boolean inactiveOnStartup = false;
 private String serviceName;
 private long initialStateRetrievalTimeout = 10000;
 private IsolationLevel isolationLevel = IsolationLevel.REPEATABLE_READ;
 @Dynamic
 private Element evictionPolicyConfig = null;
 private boolean useRegionBasedMarshalling = false;
 private String transactionManagerLookupClass = null;
 private Element cacheLoaderConfiguration = null;
 @Dynamic
 private boolean syncCommitPhase = false;
 @Dynamic
 private boolean syncRollbackPhase = false;
 private Element buddyReplicationConfig;
 private boolean nodeLockingOptimistic = false;
 private NodeLockingScheme nodeLockingScheme = NodeLockingScheme.PESSIMISTIC;
 private String muxServiceName = null;
 private String muxStackName = "fc-fast-minimalthreads";

[brian.stansberry]

You might want to ping Scott/Adrian to see how this ties in with what they are doing. They have a concept of a ManagedObject that's meant to describe this kind of thing. I'm sure tools like JBoss ON are going to want a consistent API for discovering what features are runtime changeable.

[starksm64]

The api is associated with the profile service and is rooted at the org.jboss.deployers.spi.management.ManagementView. There is simple org.jboss.deployers.spi.management.ManagedObject representation of a bean's management interface. How the ManagedObject is obtained for a component is a function of the deployer associated with the component. So far we have not gotten to how the deployers extract the ManagedObject from a deployment metadata. We'll have to define annotations and schemas for this.

Adrian did create a org.jboss.mx.mxbean.MXBean prototype that illustrates some concepts of the jdk6 MXBean:
http://download.java.net/jdk6/docs/api/javax/management/MXBean.html
http://www.jboss.com/index.html?module=bb&op=viewtopic&t=89432

[manik]

This just seems like a mechanism of how I would expose setters to allow mutation of certain configs via JMX or the profile service.

The purpose of this thread is more to talk about *how* I plan to enforce such mutability internally (since programmatically someone can still get a hold of the Configuration object and change it), as well as a discussion on which elements should be mutable.

[starksm64]

Yes, that is correct. You have to define your management interface and then expose it so that the managment layer understands it.

[ben.wang]

Manik, should useInterceptorMBean be runtime configurable as well just for the management purpose? Most of the time, I may want to turn it off for performance but use it for periodic monitoring.

[manik]

I'm ok with this being a RT variable, but then it should not be injected into the inteceptors when the chain is configured, but should be referenced directly from the Configuration.

You also suggested changing isUseInterceptorMBean to isUseMBean. +1 to both, are you going to make the change together?