Package org.exoplatform.services.rpc.impl

Class AbstractRPCService

java.lang.Object
org.exoplatform.services.rpc.impl.AbstractRPCService
All Implemented Interfaces:
RPCService, org.jgroups.blocks.RequestHandler, org.jgroups.MembershipListener, org.picocontainer.Startable
Direct Known Subclasses:
RPCServiceImpl
public abstract class AbstractRPCService extends Object implements RPCService, org.picocontainer.Startable, org.jgroups.blocks.RequestHandler, org.jgroups.MembershipListener
This class is a basic implementation of the RPCService, it is mainly based on the MessageDispatcher of JGroups. This implementation is not designed to give the best possible performances, it only aims to give a way to communicate with other nodes.
Version:
$Id$
Author:
Nicolas Filotto

  • Field Details

    • LOG

      protected static final org.exoplatform.services.log.Log LOG
      Connection logger.

    • PARAM_JGROUPS_CONFIG

      protected static final String PARAM_JGROUPS_CONFIG
      The name of the parameter for the location of the JGroups configuration.
      See Also:

    • PARAM_CLUSTER_NAME

      protected static final String PARAM_CLUSTER_NAME
      The name of the parameter for the name of the cluster.
      See Also:

    • PARAM_DEFAULT_TIMEOUT

      protected static final String PARAM_DEFAULT_TIMEOUT
      The name of the parameter for the default timeout
      See Also:

    • PARAM_ALLOW_FAILOVER

      protected static final String PARAM_ALLOW_FAILOVER
      The name of the parameter to allow the failover
      See Also:

    • PARAM_RETRY_TIMEOUT

      protected static final String PARAM_RETRY_TIMEOUT
      The name of the parameter for the retry timeout
      See Also:

    • DEFAULT_TIMEOUT

      protected static final int DEFAULT_TIMEOUT
      The value of the default timeout
      See Also:

    • DEFAULT_RETRY_TIMEOUT

      protected static final int DEFAULT_RETRY_TIMEOUT
      The value of the default retry timeout
      See Also:

    • CLUSTER_NAME

      protected static final String CLUSTER_NAME
      The default value of the cluster name
      See Also:

    • configurator

      protected final org.jgroups.conf.ProtocolStackConfigurator configurator
      The configurator used to create the JGroups Channel

    • channel

      protected org.jgroups.Channel channel
      The JGroups Channel used to communicate with other nodes

    • members

      protected volatile List<org.jgroups.Address> members
      The current list of all the members of the cluster

    • coordinator

      protected volatile org.jgroups.Address coordinator
      The address of the current coordinator

    • isCoordinator

      protected volatile boolean isCoordinator
      Indicates whether the current node is the coordinator of the cluster or not

    • dispatcher

      protected org.jgroups.blocks.MessageDispatcher dispatcher
      The dispatcher used to launch the command of the cluster nodes

  • Constructor Details

    • AbstractRPCService

      public AbstractRPCService(org.exoplatform.container.ExoContainerContext ctx, org.exoplatform.container.xml.InitParams params, org.exoplatform.container.configuration.ConfigurationManager configManager)
      The public constructor
      Parameters:
      ctx - the ExoContainerContext from which we will extract the corresponding ExoContainer
      params - the list of initial parameters
      configManager - the configuration manager used to get the configuration of JGroups

  • Method Details

    • executeCommandOnAllNodes

      public List<Object> executeCommandOnAllNodes(RemoteCommand command, boolean synchronous, Serializable... args) throws RPCException
      Executes a command on all the cluster nodes. This method is equivalent to the other method of the same type but with the default timeout. The command must be registered first otherwise an RPCException will be thrown.
      Specified by:
      executeCommandOnAllNodes in interface RPCService
      Parameters:
      command - The command to execute on each cluster node
      synchronous - if true, sets group request mode to org.jgroups.blocks.GroupRequest#GET_ALL, and if false sets it to org.jgroups.blocks.GroupRequest#GET_NONE.
      args - an array of Serializable objects corresponding to parameters of the command to execute remotely
      Returns:
      a list of responses from all the members of the cluster. If we met an exception on a given node, the RPCException will be the corresponding response of this particular node
      Throws:
      RPCException - in the event of problems.

    • executeCommandOnAllNodes

      public List<Object> executeCommandOnAllNodes(RemoteCommand command, long timeout, Serializable... args) throws RPCException
      Executes a command synchronously on all the cluster nodes. The command must be registered first otherwise an RPCException will be thrown.
      Specified by:
      executeCommandOnAllNodes in interface RPCService
      Parameters:
      command - The command to execute on each cluster node
      timeout - a timeout after which to throw a replication exception.
      args - an array of Serializable objects corresponding to parameters of the command to execute remotely
      Returns:
      a list of responses from all the members of the cluster. If we met an exception on a given node, the RPCException will be the corresponding response of this particular node
      Throws:
      RPCException - in the event of problems.

    • executeCommandOnAllNodesMain

      protected List<Object> executeCommandOnAllNodesMain(RemoteCommand command, boolean synchronous, long timeout, Serializable... args) throws RPCException
      Executes a command on all the cluster nodes. This method is equivalent to the other method of the same type but with the default timeout. The command must be registered first otherwise an RPCException will be thrown.
      Parameters:
      command - The command to execute on each cluster node
      synchronous - if true, sets group request mode to org.jgroups.blocks.GroupRequest#GET_ALL, and if false sets it to org.jgroups.blocks.GroupRequest#GET_NONE.
      timeout - a timeout after which to throw a replication exception.
      args - an array of Serializable objects corresponding to parameters of the command to execute remotely
      Returns:
      a list of responses from all the members of the cluster. If we met an exception on a given node, the RPCException will be the corresponding response of this particular node
      Throws:
      RPCException - in the event of problems.

    • executeCommandOnCoordinator

      public Object executeCommandOnCoordinator(RemoteCommand command, boolean synchronous, Serializable... args) throws RPCException
      Executes a command on the coordinator only. This method is equivalent to the other method of the same type but with the default timeout. The command must be registered first otherwise an RPCException will be thrown.
      Specified by:
      executeCommandOnCoordinator in interface RPCService
      Parameters:
      command - The command to execute on the coordinator node
      synchronous - if true, sets group request mode to org.jgroups.blocks.GroupRequest#GET_ALL, and if false sets it to org.jgroups.blocks.GroupRequest#GET_NONE.
      args - an array of Serializable objects corresponding to parameters of the command to execute remotely
      Returns:
      the response of the coordinator.
      Throws:
      RPCException - in the event of problems.

    • executeCommandOnCoordinator

      public Object executeCommandOnCoordinator(RemoteCommand command, long timeout, Serializable... args) throws RPCException
      Executes a command synchronously on the coordinator only. The command must be registered first otherwise an RPCException will be thrown.
      Specified by:
      executeCommandOnCoordinator in interface RPCService
      Parameters:
      command - The command to execute on the coordinator node
      timeout - a timeout after which to throw a replication exception.
      args - an array of Serializable objects corresponding to parameters of the command to execute remotely
      Returns:
      the response of the coordinator.
      Throws:
      RPCException - in the event of problems.

    • executeCommandOnCoordinatorMain

      protected Object executeCommandOnCoordinatorMain(RemoteCommand command, boolean synchronous, long timeout, Serializable... args) throws RPCException
      Executes a command on the coordinator only. This method is equivalent to the other method of the same type but with the default timeout. The command must be registered first otherwise an RPCException will be thrown.
      Parameters:
      command - The command to execute on the coordinator node
      synchronous - if true, sets group request mode to org.jgroups.blocks.GroupRequest#GET_ALL, and if false sets it to org.jgroups.blocks.GroupRequest#GET_NONE.
      timeout - a timeout after which to throw a replication exception.
      args - an array of Serializable objects corresponding to parameters of the command to execute remotely
      Returns:
      the response of the coordinator.
      Throws:
      RPCException - in the event of problems.

    • excecuteCommand

      protected List<Object> excecuteCommand(List<org.jgroups.Address> dests, RemoteCommand command, boolean synchronous, long timeout, Serializable... args) throws RPCException
      Execute the command on all the nodes corresponding to the list of destinations.
      Parameters:
      dests - the list of members on which the command needs to be executed
      command - the command to execute
      synchronous - if true, sets group request mode to org.jgroups.blocks.GroupRequest#GET_ALL, and if false sets it to org.jgroups.blocks.GroupRequest#GET_NONE.
      timeout - a timeout after which to throw a replication exception.
      args - the list of parameters
      Returns:
      a list of responses from all the targeted members of the cluster.
      Throws:
      RPCException - in the event of problems.

    • handle

      public Object handle(org.jgroups.Message msg)
      Specified by:
      handle in interface org.jgroups.blocks.RequestHandler

    • block

      public void block()
      Specified by:
      block in interface org.jgroups.MembershipListener

    • suspect

      public void suspect(org.jgroups.Address suspectedMbr)
      Specified by:
      suspect in interface org.jgroups.MembershipListener

    • viewAccepted

      public void viewAccepted(org.jgroups.View view)
      Specified by:
      viewAccepted in interface org.jgroups.MembershipListener

    • registerCommand

      public RemoteCommand registerCommand(RemoteCommand command)
      Register a new RemoteCommand instance, it will be mapped to its id. If a command with the same Id has already been registered, a warning will be printed into the log file and the new command will replace the old one.
      Specified by:
      registerCommand in interface RPCService
      Parameters:
      command - the instance of the RemoteCommand to register
      Returns:
      the command itself if it could be registered null otherwise

    • unregisterCommand

      public void unregisterCommand(RemoteCommand command)
      Unregister a RemoteCommand instance, if the id is known or the instance itself is known otherwise it will be ignored
      Specified by:
      unregisterCommand in interface RPCService
      Parameters:
      command - the command to unregister

    • isCoordinator

      public boolean isCoordinator() throws RPCException
      Indicates whether the local node is the coordinator of the cluster
      Specified by:
      isCoordinator in interface RPCService
      Returns:
      true if the coordinator is the coordinator, false otherwise throws RPCException in case the RPCService is in an illegal state
      Throws:
      RPCException

    • registerTopologyChangeListener

      public void registerTopologyChangeListener(TopologyChangeListener listener) throws SecurityException
      Register a new TopologyChangeListener
      Specified by:
      registerTopologyChangeListener in interface RPCService
      Parameters:
      listener - the listener to be registered
      Throws:
      SecurityException - if the SecurityManager is installed and the call method doesn't have the RuntimePermission ACCESS_RPC_SERVICE_PERMISSION

    • unregisterTopologyChangeListener

      public void unregisterTopologyChangeListener(TopologyChangeListener listener) throws SecurityException
      Unregister a TopologyChangeListener if it exists
      Specified by:
      unregisterTopologyChangeListener in interface RPCService
      Parameters:
      listener - the listener to unregister
      Throws:
      SecurityException - if the SecurityManager is installed and the call method doesn't have the RuntimePermission ACCESS_RPC_SERVICE_PERMISSION

    • getCommand

      protected RemoteCommand getCommand(String commandId)
      Gives the RemoteCommand corresponding to the given id
      Parameters:
      commandId - the command id of the command to retrieve
      Returns:
      the corresponding RemoteCommand

    • start

      public void start()
      Specified by:
      start in interface org.picocontainer.Startable

    • stop

      public void stop()
      Specified by:
      stop in interface org.picocontainer.Startable

    • getDefaultTimeout

      protected long getDefaultTimeout()
      Gives the value of the default timeout
      Returns:
      the default timeout

    • getClusterName

      protected String getClusterName()
      Gives the name of the cluster
      Returns:
      the name of the cluster

    • getRetryTimeout

      protected long getRetryTimeout()
      Gives the value of the retry timeout
      Returns:
      the value of the retry timeout

    • isAllowFailover

      protected boolean isAllowFailover()
      Indicates whether the failover capabilities are enabled or not
      Returns:
      true if the failover capabilities are allowed, false otherwise

    • getLocalAddress

      protected abstract org.jgroups.Address getLocalAddress()
      Returns the channel's own address. The result of calling this method on an unconnected channel is implementation defined (may return null). Calling this method on a closed channel returns null. Successor to #getAddress(). Addresses can be used as destination in the send() operation.
      Returns:
      The channel's address (opaque) or null if it cannot be found

    • getHostAddress

      public abstract String getHostAddress()
      Returns the IP address of current channel.
      Returns:
      The Host's address or null if it cannot be found

    • castMessage

      protected abstract org.jgroups.util.RspList castMessage(List<org.jgroups.Address> dests, org.jgroups.Message msg, boolean synchronous, long timeout) throws Exception
      Cast a message to all the given members
      Parameters:
      dests - The members to which the message is to be sent.
      msg - The message to be sent to the members.
      synchronous - Indicates whether the message must be sent in synchronous or asynchronous mode.
      timeout - If 0: wait forever. Otherwise, wait for responses or timeout time.
      Returns:
      A list of responses. Each response is an Object and associated to its sender.
      Throws:
      Exception - if any error occur while casting the message

    • createChannel

      protected abstract org.jgroups.Channel createChannel() throws Exception
      Create a channel
      Returns:
      An initialized channel
      Throws:
      Exception - if any error occur while creating the channel

    • getMembers

      protected abstract List<org.jgroups.Address> getMembers(org.jgroups.View view)
      Returns a reference to the List of members (ordered) Do NOT change this list, hence your will invalidate the view Make a copy if you have to modify it.
      Returns:
      a reference to the ordered list of members in this view

    • setObject

      protected abstract void setObject(org.jgroups.Message m, Object o)
      Takes an object and uses Java serialization to generate the byte[] buffer which is set in the message.