path: root/src/mongo/db/repl/heartbeat.cpp

/**
*    Copyright (C) 2008 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,b
*    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 <http://www.gnu.org/licenses/>.
*
*    As a special exception, the copyright holders give permission to link the
*    code of portions of this program with the OpenSSL library under certain
*    conditions as described in each individual source file and distribute
*    linked combinations including the program with the OpenSSL library. You
*    must comply with the GNU Affero General Public License in all respects for
*    all of the code used other than as permitted herein. If you modify file(s)
*    with this exception, you may extend this exception to your version of the
*    file(s), but you are not obligated to do so. If you do not wish to do so,
*    delete this exception statement from your version. If you delete this
*    exception statement from all source files in the program, then also delete
*    it in the license file.
*/

#include "mongo/pch.h"

#include <boost/thread/thread.hpp>

#include "mongo/db/commands.h"
#include "mongo/db/instance.h"
#include "mongo/db/repl/bgsync.h"
#include "mongo/db/repl/connections.h"
#include "mongo/db/repl/heartbeat_info.h"
#include "mongo/db/repl/repl_settings.h"  // replSettings
#include "mongo/db/repl/replset_commands.h"
#include "mongo/db/repl/rs.h"
#include "mongo/db/repl/repl_set_health_poll_task.h"
#include "mongo/db/repl/server.h"
#include "mongo/util/background.h"
#include "mongo/util/concurrency/task.h"
#include "mongo/util/fail_point_service.h"
#include "mongo/util/goodies.h"
#include "mongo/util/mongoutils/html.h"
#include "mongo/util/ramlog.h"

namespace mongo {
namespace repl {

    using namespace bson;

    MONGO_FP_DECLARE(rsDelayHeartbeatResponse);
    MONGO_FP_DECLARE(rsStopHeartbeatRequest);

    /* { replSetHeartbeat : <setname> } */
    class CmdReplSetHeartbeat : public ReplSetCommand {
    public:
        void help(stringstream& h) const { h << "internal"; }
        CmdReplSetHeartbeat() : ReplSetCommand("replSetHeartbeat") { }
        virtual void addRequiredPrivileges(const std::string& dbname,
                                           const BSONObj& cmdObj,
                                           std::vector<Privilege>* out) {
            ActionSet actions;
            actions.addAction(ActionType::internal);
            out->push_back(Privilege(ResourcePattern::forClusterResource(), actions));
        }
        virtual bool run(OperationContext* txn, const string& , BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
            if( replSetBlind ) {
                if (theReplSet) {
                    errmsg = str::stream() << theReplSet->selfFullName() << " is blind";
                }
                return false;
            }

            MONGO_FAIL_POINT_BLOCK(rsDelayHeartbeatResponse, delay) {
                const BSONObj& data = delay.getData();
                sleepsecs(data["delay"].numberInt());
            }

            /* we don't call ReplSetCommand::check() here because heartbeat
               checks many things that are pre-initialization. */
            if( !replSet ) {
                errmsg = "not running with --replSet";
                return false;
            }

            /* we want to keep heartbeat connections open when relinquishing primary.  tag them here. */
            {
                AbstractMessagingPort *mp = cc().port();
                if( mp )
                    mp->tag |= ScopedConn::keepOpen;
            }

            if( cmdObj["pv"].Int() != 1 ) {
                errmsg = "incompatible replset protocol version";
                return false;
            }
            {
                string s = string(cmdObj.getStringField("replSetHeartbeat"));
                if (replSettings.ourSetName() != s) {
                    errmsg = "repl set names do not match";
                    log() << "replSet set names do not match, our cmdline: " << replSettings.replSet
                          << rsLog;
                    log() << "replSet s: " << s << rsLog;
                    result.append("mismatch", true);
                    return false;
                }
            }

            result.append("rs", true);
            if( cmdObj["checkEmpty"].trueValue() ) {
                result.append("hasData", replHasDatabases(txn));
            }
            if( (theReplSet == 0) || (theReplSet->startupStatus == ReplSetImpl::LOADINGCONFIG) ) {
                string from( cmdObj.getStringField("from") );
                if( !from.empty() ) {
                    scoped_lock lck( replSettings.discoveredSeeds_mx );
                    replSettings.discoveredSeeds.insert(from);
                }
                result.append("hbmsg", "still initializing");
                return true;
            }

            if( theReplSet->name() != cmdObj.getStringField("replSetHeartbeat") ) {
                errmsg = "repl set names do not match (2)";
                result.append("mismatch", true);
                return false;
            }
            result.append("set", theReplSet->name());

            MemberState currentState = theReplSet->state();
            result.append("state", currentState.s);
            if (currentState == MemberState::RS_PRIMARY) {
                result.appendDate("electionTime", theReplSet->getElectionTime().asDate());
            }

            result.append("e", theReplSet->iAmElectable());
            result.append("hbmsg", theReplSet->hbmsg());
            result.append("time", (long long) time(0));
            result.appendDate("opTime", theReplSet->lastOpTimeWritten.asDate());
            const Member *syncTarget = BackgroundSync::get()->getSyncTarget();
            if (syncTarget) {
                result.append("syncingTo", syncTarget->fullName());
            }

            int v = theReplSet->config().version;
            result.append("v", v);
            if( v > cmdObj["v"].Int() )
                result << "config" << theReplSet->config().asBson();

            Member* from = NULL;
            if (cmdObj.hasField("fromId")) {
                if (v == cmdObj["v"].Int()) {
                    from = theReplSet->getMutableMember(cmdObj["fromId"].Int());
                }
            }
            if (!from) {
                from = theReplSet->findByName(cmdObj.getStringField("from"));
                if (!from) {
                    return true;
                }
            }

            // if we thought that this node is down, let it know
            if (!from->hbinfo().up()) {
                result.append("stateDisagreement", true);
            }

            // note that we got a heartbeat from this node
            theReplSet->mgr->send(stdx::bind(&ReplSet::msgUpdateHBRecv,
                                              theReplSet, from->hbinfo().id(), time(0)));


            return true;
        }
    } cmdReplSetHeartbeat;

    bool requestHeartbeat(const std::string& setName,
                          const std::string& from,
                          const std::string& memberFullName,
                          BSONObj& result,
                          int myCfgVersion,
                          int& theirCfgVersion,
                          bool checkEmpty) {
        if( replSetBlind ) {
            return false;
        }

        MONGO_FAIL_POINT_BLOCK(rsStopHeartbeatRequest, member) {
            const BSONObj& data = member.getData();
            const std::string& stopMember = data["member"].str();

            if (memberFullName == stopMember) {
                return false;
            }
        }
        int me = -1;
        if (theReplSet) {
            me = theReplSet->selfId();
        }

        BSONObjBuilder cmdBuilder;
        cmdBuilder.append("replSetHeartbeat", setName);
        cmdBuilder.append("v", myCfgVersion);
        cmdBuilder.append("pv", 1);
        cmdBuilder.append("checkEmpty", checkEmpty);
        cmdBuilder.append("from", from);
        if (me > -1) {
            cmdBuilder.append("fromId", me);
        }

        ScopedConn conn(memberFullName);
        return conn.runCommand("admin", cmdBuilder.done(), result, 0);
    }

    void ReplSetImpl::endOldHealthTasks() {
        unsigned sz = healthTasks.size();
        for( set<ReplSetHealthPollTask*>::iterator i = healthTasks.begin(); i != healthTasks.end(); i++ )
            (*i)->halt();
        healthTasks.clear();
        if( sz )
            DEV log() << "replSet debug: cleared old tasks " << sz << endl;
    }

    void ReplSetImpl::startHealthTaskFor(Member *m) {
        DEV log() << "starting rsHealthPoll for " << m->fullName() << endl;
        ReplSetHealthPollTask *task = new ReplSetHealthPollTask(m->h(), m->hbinfo());
        healthTasks.insert(task);
        task::repeat(task, 2000);
    }

    void startSyncThread();

    /** called during repl set startup.  caller expects it to return fairly quickly.
        note ReplSet object is only created once we get a config - so this won't run
        until the initiation.
    */
    void ReplSetImpl::startThreads() {
        task::fork(mgr);
        mgr->send( stdx::bind(&Manager::msgCheckNewState, theReplSet->mgr) );

        if (myConfig().arbiterOnly) {
            return;
        }

        // this ensures that will have bgsync's s_instance at all points where it is needed
        // so that we needn't check for its existence
        BackgroundSync* sync = BackgroundSync::get();

        boost::thread t(startSyncThread);

        boost::thread producer(stdx::bind(&BackgroundSync::producerThread, sync));
        theReplSet->syncSourceFeedback.go();

        // member heartbeats are started in ReplSetImpl::initFromConfig
    }

} // namespace repl
} // namespace mongo

/* todo:
   stop bg job and delete on removefromset
*/