com.bigdata.ha.QuorumRead Maven / Gradle / Ivy
/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
[email protected]
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Jun 13, 2010
*/
package com.bigdata.ha;
import java.io.IOException;
import java.util.UUID;
import com.bigdata.quorum.Quorum;
import com.bigdata.rawstore.IRawStore;
/**
* A non-remote interface for a member service in a {@link Quorum} defining
* methods to support reading on another member of the quorum.
*
* @author Bryan Thompson
* @version $Id$
*/
public interface QuorumRead { // extends QuorumService {
/**
* Used by any service joined with the quorum to read a record from another
* service joined with the quorum in order to work around a "bad read" as
* identified by a checksum error on the local service.
*
* Note: This is NOT the normal path for reading on a record from a service.
* This is used to handle bad reads (when a checksum or IO error is reported
* by the local disk) by reading the record from another member of the
* quorum.
*
* @param storeId
* The {@link UUID} of the {@link IRawStore} from which the
* record should be read.
* @param addr
* The address of a record on that store.
*
* @return The record.
*
* @throws IllegalStateException
* if the quorum is not highly available.
* @throws RuntimeException
* if the quorum is highly available but the record could not be
* read.
*
* @see HAGlue#readFromDisk(UUID, long)
*/
byte[] readFromQuorum(UUID storeId, long addr) throws InterruptedException,
IOException;
}