238 lines
8.3 KiB
C++
238 lines
8.3 KiB
C++
/**
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* Copyright (C) 2010 10gen Inc.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License, version 3,
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "pch.h"
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#include "../commands.h"
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#include "rs.h"
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#include "multicmd.h"
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namespace mongo {
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class CmdReplSetFresh : public ReplSetCommand {
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public:
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CmdReplSetFresh() : ReplSetCommand("replSetFresh") { }
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private:
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virtual bool run(const string& , BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
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if( !check(errmsg, result) )
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return false;
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if( cmdObj["set"].String() != theReplSet->name() ) {
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errmsg = "wrong repl set name";
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return false;
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}
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string who = cmdObj["who"].String();
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int cfgver = cmdObj["cfgver"].Int();
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bool weAreFresher = false;
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if( theReplSet->config().version > cfgver ) {
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log() << "replSet member " << who << " is not yet aware its cfg version " << cfgver << " is stale" << rsLog;
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weAreFresher = true;
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}
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result.append("fresher", weAreFresher);
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log() << "replSet error: replSetFresh command not implemented yet." << rsLog;
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return true;
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}
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} cmdReplSetFresh;
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class CmdReplSetElect : public ReplSetCommand {
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public:
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CmdReplSetElect() : ReplSetCommand("replSetElect") { }
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private:
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virtual bool run(const string& , BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
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if( !check(errmsg, result) )
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return false;
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//task::lam f = boost::bind(&Consensus::electCmdReceived, &theReplSet->elect, cmdObj, &result);
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//theReplSet->mgr->call(f);
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theReplSet->elect.electCmdReceived(cmdObj, &result);
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return true;
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}
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} cmdReplSetElect;
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int Consensus::totalVotes() const {
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static int complain = 0;
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int vTot = rs._self->config().votes;
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for( Member *m = rs.head(); m; m=m->next() )
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vTot += m->config().votes;
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if( vTot % 2 == 0 && vTot && complain++ == 0 )
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log() << "replSet warning total number of votes is even - considering giving one member an extra vote" << rsLog;
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return vTot;
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}
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bool Consensus::aMajoritySeemsToBeUp() const {
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int vUp = rs._self->config().votes;
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for( Member *m = rs.head(); m; m=m->next() )
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vUp += m->hbinfo().up() ? m->config().votes : 0;
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return vUp * 2 > totalVotes();
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}
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static const int VETO = -10000;
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class VoteException : public std::exception {
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};
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const time_t LeaseTime = 30;
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unsigned Consensus::yea(unsigned memberId) /* throws VoteException */ {
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Atomic<LastYea>::tran t(ly);
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LastYea &ly = t.ref();
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time_t now = time(0);
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if( ly.when + LeaseTime >= now && ly.who != memberId ) {
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log() << "replSet TEMP not voting yea for " << memberId << rsLog;
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log() << "replSet TEMP voted for " << ly.who << ' ' << now-ly.when << " secs ago" << rsLog;
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throw VoteException();
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}
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ly.when = now;
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ly.who = memberId;
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return rs._self->config().votes;
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}
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/* todo: threading **************** !!!!!!!!!!!!!!!! */
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void Consensus::electCmdReceived(BSONObj cmd, BSONObjBuilder* _b) {
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BSONObjBuilder& b = *_b;
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log() << "replSet TEMP RECEIVED ELECT MSG " << cmd.toString() << rsLog;
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string set = cmd["set"].String();
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unsigned whoid = cmd["whoid"].Int();
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int cfgver = cmd["cfgver"].Int();
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OID round = cmd["round"].OID();
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int myver = rs.config().version;
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int vote = 0;
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if( set != rs.name() ) {
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log() << "replSet error received an elect request for '" << set << "' but our set name is '" << rs.name() << "'" << rsLog;
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}
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else if( myver < cfgver ) {
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// we are stale. don't vote
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}
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else if( myver > cfgver ) {
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// they are stale!
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log() << "replSet info got stale version # during election" << rsLog;
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vote = -10000;
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}
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else {
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try {
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vote = yea(whoid);
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rs.relinquish();
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log() << "replSet info voting yea for " << whoid << rsLog;
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}
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catch(VoteException&) {
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log() << "replSet voting no already voted for another" << rsLog;
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}
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}
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b.append("vote", vote);
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b.append("round", round);
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}
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void ReplSetImpl::getTargets(list<Target>& L) {
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for( Member *m = head(); m; m=m->next() )
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if( m->hbinfo().up() )
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L.push_back( Target(m->fullName()) );
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}
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/* allUp only meaningful when true returned! */
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bool Consensus::weAreFreshest(bool& allUp) {
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BSONObj cmd = BSON(
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"replSetFresh" << 1 <<
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"set" << rs.name() <<
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"who" << rs._self->fullName() <<
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"cfgver" << rs._cfg->version );
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list<Target> L;
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rs.getTargets(L);
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multiCommand(cmd, L);
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int nok = 0;
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allUp = true;
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for( list<Target>::iterator i = L.begin(); i != L.end(); i++ ) {
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if( i->ok ) {
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nok++;
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if( i->result["fresher"].trueValue() )
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return false;
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}
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else {
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log() << "replSet TEMP freshest returns " << i->result.toString() << rsLog;
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allUp = false;
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}
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}
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log() << "replSet TEMP we are freshest of up nodes, nok:" << nok << rsLog;
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return true;
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}
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extern time_t started;
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void Consensus::_electSelf() {
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bool allUp;
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if( !weAreFreshest(allUp) ) {
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log() << "replSet info not electing self, we are not freshest" << rsLog;
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return;
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}
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if( !allUp && time(0) - started < 60 * 5 ) {
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log() << "replSet info not electing self, not all members up and we have been up less than 5 minutes" << rsLog;
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}
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time_t start = time(0);
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Member& me = *rs._self;
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int tally = yea( me.id() );
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log() << "replSet info electSelf" << rsLog;
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BSONObj electCmd = BSON(
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"replSetElect" << 1 <<
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"set" << rs.name() <<
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"who" << me.fullName() <<
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"whoid" << me.hbinfo().id() <<
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"cfgver" << rs._cfg->version <<
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"round" << OID::gen() /* this is just for diagnostics */
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);
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list<Target> L;
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rs.getTargets(L);
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multiCommand(electCmd, L);
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for( list<Target>::iterator i = L.begin(); i != L.end(); i++ ) {
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log() << "replSet TEMP elect res: " << i->result.toString() << rsLog;
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Target& t = *i;
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if( i->ok ) {
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int v = i->result["vote"].Int();
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tally += v;
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}
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}
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if( tally*2 > totalVotes() ) {
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if( time(0) - start > 30 ) {
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// defensive; should never happen as we have timeouts on connection and operation for our conn
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log() << "replSet too much time passed during election, ignoring result" << rsLog;
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}
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/* succeeded. */
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log() << "replSet election succeeded assuming primary role" << rsLog;
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rs.assumePrimary();
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return;
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}
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else {
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log() << "replSet couldn't elect self, only received " << tally << " votes" << rsLog;
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}
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}
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void Consensus::electSelf() {
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try {
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_electSelf();
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}
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catch(VoteException& ) {
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log() << "replSet not trying to elect self as responded yea to someone else recently" << rsLog;
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}
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catch(...) { }
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}
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}
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