com.bigdata.jini.start.config
Class MaxServicesPerHostConstraint

java.lang.Object
  com.bigdata.jini.start.config.MaxServicesPerHostConstraint

All Implemented Interfaces:

IServiceConstraint, Serializable

Direct Known Subclasses:

MaxClientServicesPerHostConstraint, MaxDataServicesPerHostConstraint

public abstract class MaxServicesPerHostConstraint
extends Object
implements IServiceConstraint

Places a limit on the #of instances of a service which can be created on the same host. Jini is used to discover the instances of the specified class of service. The constraint is satisified iff the #of discovered instances is less than the maximum.

Note: Since jini does not directly report the hostname of a service, this relies on the Hostname attribute which is placed onto the bigdata service instances.

Note: Since a MetadataService is a DataService, you want to use MetadataServer.AdministrableMetadataService and DataServer.AdministrableDataService to specify the constraints for those services. If you use only IDataService or DataService the constraint will be applied to both and instances of both will be counted against the maximum.

Version:

$Id$

Author:

Bryan Thompson

See Also:

MonitorCreatePhysicalServiceLocksTask, Serialized Form

TODO:

Other kinds of constraints could limit the mixture of services that may run on a host. For example, do not run any other service on a host running zookeeper (or listed as a zookeeper server) or on a host running the MetadataService.

Field Summary

protected static org.apache.log4j.Logger	log
protected int	maxServices

Constructor Summary

MaxServicesPerHostConstraint(int maxServices)

Method Summary

String

toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.bigdata.jini.start.config.IServiceConstraint

allow

Field Detail

log

protected static final org.apache.log4j.Logger log

maxServices

protected final int maxServices

Constructor Detail

MaxServicesPerHostConstraint

public MaxServicesPerHostConstraint(int maxServices)

Parameters:

maxServices - The maximum #of services which are instances of that class or interface which may run on any given host.

Method Detail

toString

public String toString()

Overrides:

toString in class Object