// @file writeback_listener.h
/**
* Copyright (C) 2010 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*/
#pragma once
#include "../pch.h"
#include "../client/connpool.h"
#include "../util/background.h"
#include "../db/client.h"
namespace mongo {
/*
* The writeback listener takes back write attempts that were made against a wrong shard.
* (Wrong here in the sense that the target chunk moved before this mongos had a chance to
* learn so.) It is responsible for reapplying these writes to the correct shard.
*
* Currently, there is one listener per shard.
*/
class WriteBackListener : public BackgroundJob {
public:
static void init( DBClientBase& conn );
static void init( const string& host );
static BSONObj waitFor( ConnectionId connectionId, const OID& oid );
protected:
WriteBackListener( const string& addr );
string name() const { return "WriteBackListener"; }
void run();
private:
string _addr;
static mongo::mutex _cacheLock; // protects _cache
static map _cache; // server to listener
static set _seenSets; // cache of set urls we've seen - note this is ever expanding for order, case, changes
struct WBStatus {
OID id;
BSONObj gle;
};
static mongo::mutex _seenWritebacksLock; // protects _seenWritbacks
static map _seenWritebacks; // connectionId -> last write back GLE
};
void waitForWriteback( const OID& oid );
} // namespace mongo