oracle.kv.impl.api.RequestHandler Maven / Gradle / Ivy
/*-
* Copyright (C) 2011, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This file was distributed by Oracle as part of a version of Oracle NoSQL
* Database made available at:
*
* http://www.oracle.com/technetwork/database/database-technologies/nosqldb/downloads/index.html
*
* Please see the LICENSE file included in the top-level directory of the
* appropriate version of Oracle NoSQL Database for a copy of the license and
* additional information.
*/
package oracle.kv.impl.api;
import java.rmi.RemoteException;
import oracle.kv.FaultException;
import oracle.kv.impl.util.registry.VersionedRemote;
/**
* Handles requests that have been directed to this RN by some
* {@link RequestDispatcher}. It's ultimately responsible for the
* execution of a request that originated at a KV Client.
*/
public interface RequestHandler extends VersionedRemote {
/**
* Executes the request. It identifies the database that owns the keys
* associated with the request and executes the request.
*
*
* The local request handler contains the retry logic for all failures that
* can be handled locally. For example, a retry resulting from an
* environment handle that was invalidated due to a hard recovery in the
* midst of an operation. Exceptional situations that cannot be
* handled internally are propagated back to the client.
*
* It may not be possible to initiate execution of the request because the
* request was misdirected and the RN does not own the key, or because the
* request is for an update and the RN is not a master. In these cases,
* it internally redirects the request to a more appropriate RN and returns
* the response or exception as appropriate.
*
* @param request the request to be executed
*
* @return the response from the execution of the request
*/
public Response execute(Request request)
throws FaultException, RemoteException;
}