C++ DBConfigPtr::getChunkManagerIfExists方法代码示例

        // TODO: This refresh logic should be consolidated
        void refreshChunkCache( const NamespaceString& nss ) {

            DBConfigPtr config = grid.getDBConfig( nss.ns() );
            if ( !config->isSharded( nss ) ) return;

            // Refreshes chunks as a side-effect
            config->getChunkManagerIfExists( nss, true );
        }

    bool forceRemoteCheckShardVersion( const string& ns ){

        DBConfigPtr conf = grid.getDBConfig( ns );
        if ( ! conf ) return false;
        conf->reload();

        ChunkManagerPtr manager = conf->getChunkManagerIfExists( ns, true, true );
        if( ! manager ) return false;

        return true;

    }

    Status ChunkManagerTargeter::refreshNow( RefreshType refreshType ) {

        DBConfigPtr config;

        string errMsg;
        if ( !getDBConfigSafe( _nss.db(), config, &errMsg ) ) {
            return Status( ErrorCodes::DatabaseNotFound, errMsg );
        }

        // Try not to spam the configs
        refreshBackoff();

        // TODO: Improve synchronization and make more explicit
        if ( refreshType == RefreshType_RefreshChunkManager ) {
            try {
                // Forces a remote check of the collection info, synchronization between threads
                // happens internally.
                config->getChunkManagerIfExists( _nss.ns(), true );
            }
            catch ( const DBException& ex ) {
                return Status( ErrorCodes::UnknownError, ex.toString() );
            }
            config->getChunkManagerOrPrimary( _nss.ns(), _manager, _primary );
        }
        else if ( refreshType == RefreshType_ReloadDatabase ) {
            try {
                // Dumps the db info, reloads it all, synchronization between threads happens
                // internally.
                config->reload();
                config->getChunkManagerIfExists( _nss.ns(), true, true );
            }
            catch ( const DBException& ex ) {
                return Status( ErrorCodes::UnknownError, ex.toString() );
            }
            config->getChunkManagerOrPrimary( _nss.ns(), _manager, _primary );
        }

        return Status::OK();
    }

    bool VersionManager::forceRemoteCheckShardVersionCB( const string& ns ){

        DBConfigPtr conf = grid.getDBConfig( ns );
        if ( ! conf ) return false;
        conf->reload();

        // If we don't have a collection, don't refresh the chunk manager
        if( nsGetCollection( ns ).size() == 0 ) return false;

        ChunkManagerPtr manager = conf->getChunkManagerIfExists( ns, true, true );
        if( ! manager ) return false;

        return true;

    }

    /**
     * @return true if had to do something
     */
    bool checkShardVersion( DBClientBase * conn_in , const string& ns , ChunkManagerPtr refManager, bool authoritative , int tryNumber ) {
        // TODO: cache, optimize, etc...

        WriteBackListener::init( *conn_in );

        DBConfigPtr conf = grid.getDBConfig( ns );
        if ( ! conf )
            return false;

        DBClientBase* conn = getVersionable( conn_in );
        verify(conn); // errors thrown above

        unsigned long long officialSequenceNumber = 0;

        ChunkManagerPtr manager;
        const bool isSharded = conf->isSharded( ns );
        if ( isSharded ) {
            manager = conf->getChunkManagerIfExists( ns , authoritative );
            // It's possible the chunk manager was reset since we checked whether sharded was true,
            // so must check this here.
            if( manager ) officialSequenceNumber = manager->getSequenceNumber();
        }

        // Check this manager against the reference manager
        if( isSharded && manager ){

            Shard shard = Shard::make( conn->getServerAddress() );
            if( refManager && ! refManager->compatibleWith( manager, shard ) ){
                throw SendStaleConfigException( ns, str::stream() << "manager (" << manager->getVersion( shard ).toString()  << " : " << manager->getSequenceNumber() << ") "
                                                                      << "not compatible with reference manager (" << refManager->getVersion( shard ).toString()  << " : " << refManager->getSequenceNumber() << ") "
                                                                      << "on shard " << shard.getName() << " (" << shard.getAddress().toString() << ")",
                                                refManager->getVersion( shard ), manager->getVersion( shard ) );
            }
        }
        else if( refManager ){
            Shard shard = Shard::make( conn->getServerAddress() );
            string msg( str::stream() << "not sharded ("
                        << ( (manager.get() == 0) ? string( "<none>" ) :
                                str::stream() << manager->getSequenceNumber() )
                        << ") but has reference manager ("
                        << refManager->getSequenceNumber() << ") "
                        << "on conn " << conn->getServerAddress() << " ("
                        << conn_in->getServerAddress() << ")" );

            throw SendStaleConfigException( ns, msg,
                    refManager->getVersion( shard ), ShardChunkVersion( 0, OID() ));
        }

        // has the ChunkManager been reloaded since the last time we updated the connection-level version?
        // (ie., last time we issued the setShardVersions below)
        unsigned long long sequenceNumber = connectionShardStatus.getSequence(conn,ns);
        if ( sequenceNumber == officialSequenceNumber ) {
            return false;
        }


        ShardChunkVersion version = ShardChunkVersion( 0, OID() );
        if ( isSharded && manager ) {
            version = manager->getVersion( Shard::make( conn->getServerAddress() ) );
        }

        if( ! version.isSet() ){
            LOG(0) << "resetting shard version of " << ns << " on " << conn->getServerAddress() << ", " <<
                      ( ! isSharded ? "no longer sharded" :
                      ( ! manager ? "no chunk manager found" :
                                    "version is zero" ) ) << endl;
        }

        LOG(2) << " have to set shard version for conn: " << conn->getServerAddress() << " ns:" << ns
               << " my last seq: " << sequenceNumber << "  current: " << officialSequenceNumber
               << " version: " << version << " manager: " << manager.get()
               << endl;

        const string versionableServerAddress(conn->getServerAddress());

        BSONObj result;
        if ( setShardVersion( *conn , ns , version , authoritative , result ) ) {
            // success!
            LOG(1) << "      setShardVersion success: " << result << endl;
            connectionShardStatus.setSequence( conn , ns , officialSequenceNumber );
            return true;
        }

        LOG(1) << "       setShardVersion failed!\n" << result << endl;

        if ( result["need_authoritative"].trueValue() )
            massert( 10428 ,  "need_authoritative set but in authoritative mode already" , ! authoritative );

        if ( ! authoritative ) {
            // use the original connection and get a fresh versionable connection
            // since conn can be invalidated (or worse, freed) after the failure
            checkShardVersion(conn_in, ns, refManager, 1, tryNumber + 1);
            return true;
        }
        
        if ( result["reloadConfig"].trueValue() ) {
            if( result["version"].timestampTime() == 0 ){
//.........这里部分代码省略.........

    /**
     * @return true if had to do something
     */
    bool checkShardVersion( DBClientBase& conn_in , const string& ns , bool authoritative , int tryNumber ) {
        // TODO: cache, optimize, etc...

        WriteBackListener::init( conn_in );

        DBConfigPtr conf = grid.getDBConfig( ns );
        if ( ! conf )
            return false;

        DBClientBase* conn = 0;

        switch ( conn_in.type() ) {
        case ConnectionString::INVALID:
            assert(0);
            break;
        case ConnectionString::MASTER:
            // great
            conn = &conn_in;
            break;
        case ConnectionString::PAIR:
            assert( ! "pair not support for sharding" );
            break;
        case ConnectionString::SYNC:
            // TODO: we should check later that we aren't actually sharded on this
            conn = &conn_in;
            break;
        case ConnectionString::SET:
            DBClientReplicaSet* set = (DBClientReplicaSet*)&conn_in;
            conn = &(set->masterConn());
            break;
        }

        assert(conn);

        unsigned long long officialSequenceNumber = 0;

        ChunkManagerPtr manager;
        const bool isSharded = conf->isSharded( ns );
        if ( isSharded ) {
            manager = conf->getChunkManagerIfExists( ns , authoritative );
            // It's possible the chunk manager was reset since we checked whether sharded was true,
            // so must check this here.
            if( manager ) officialSequenceNumber = manager->getSequenceNumber();
        }

        // has the ChunkManager been reloaded since the last time we updated the connection-level version?
        // (ie., last time we issued the setShardVersions below)
        unsigned long long sequenceNumber = connectionShardStatus.getSequence(conn,ns);
        if ( sequenceNumber == officialSequenceNumber ) {
            return false;
        }


        ShardChunkVersion version = 0;
        if ( isSharded && manager ) {
            version = manager->getVersion( Shard::make( conn->getServerAddress() ) );
        }

        LOG(2) << " have to set shard version for conn: " << conn << " ns:" << ns
               << " my last seq: " << sequenceNumber << "  current: " << officialSequenceNumber
               << " version: " << version << " manager: " << manager.get()
               << endl;

        BSONObj result;
        if ( setShardVersion( *conn , ns , version , authoritative , result ) ) {
            // success!
            LOG(1) << "      setShardVersion success: " << result << endl;
            connectionShardStatus.setSequence( conn , ns , officialSequenceNumber );
            return true;
        }

        LOG(1) << "       setShardVersion failed!\n" << result << endl;

        if ( result["need_authoritative"].trueValue() )
            massert( 10428 ,  "need_authoritative set but in authoritative mode already" , ! authoritative );

        if ( ! authoritative ) {
            checkShardVersion( *conn , ns , 1 , tryNumber + 1 );
            return true;
        }
        
        if ( result["reloadConfig"].trueValue() ) {
            if( result["version"].timestampTime() == 0 ){
                // reload db
                conf->reload();
            }
            else {
                // reload config
                conf->getChunkManager( ns , true );
            }
        }

        const int maxNumTries = 7;
        if ( tryNumber < maxNumTries ) {
            LOG( tryNumber < ( maxNumTries / 2 ) ? 1 : 0 ) 
                << "going to retry checkShardVersion host: " << conn->getServerAddress() << " " << result << endl;
            sleepmillis( 10 * tryNumber );
//.........这里部分代码省略.........

//.........这里部分代码省略.........
            if (shardToChunksMap.map().empty()) {
                LOG(1) << "skipping empty collection (" << ns << ")";
                continue;
            }

            for (ShardInfoMap::const_iterator i = shardInfo.begin(); i != shardInfo.end(); ++i) {
                // this just makes sure there is an entry in shardToChunksMap for every shard
                OwnedPointerVector<ChunkType>*& chunkList =
                        shardToChunksMap.mutableMap()[i->first];

                if (chunkList == NULL) {
                    chunkList = new OwnedPointerVector<ChunkType>();
                }
            }

            DistributionStatus status(shardInfo, shardToChunksMap.map());

            // load tags
            Status result = clusterCreateIndex(TagsType::ConfigNS,
                                               BSON(TagsType::ns() << 1 << TagsType::min() << 1),
                                               true, // unique
                                               WriteConcernOptions::AllConfigs,
                                               NULL);

            if ( !result.isOK() ) {
                warning() << "could not create index tags_1_min_1: " << result.reason() << endl;
                continue;
            }

            cursor = conn.query(TagsType::ConfigNS,
                                QUERY(TagsType::ns(ns)).sort(TagsType::min()));

            vector<TagRange> ranges;

            while ( cursor->more() ) {
                BSONObj tag = cursor->nextSafe();
                TagRange tr(tag[TagsType::min()].Obj().getOwned(),
                            tag[TagsType::max()].Obj().getOwned(),
                            tag[TagsType::tag()].String());
                ranges.push_back(tr);
                uassert(16356,
                        str::stream() << "tag ranges not valid for: " << ns,
                        status.addTagRange(tr) );

            }
            cursor.reset();

            DBConfigPtr cfg = grid.getDBConfig( ns );
            if ( !cfg ) {
                warning() << "could not load db config to balance " << ns << " collection" << endl;
                continue;
            }

            // This line reloads the chunk manager once if this process doesn't know the collection
            // is sharded yet.
            ChunkManagerPtr cm = cfg->getChunkManagerIfExists( ns, true );
            if ( !cm ) {
                warning() << "could not load chunks to balance " << ns << " collection" << endl;
                continue;
            }

            // loop through tags to make sure no chunk spans tags; splits on tag min. for all chunks
            bool didAnySplits = false;
            for ( unsigned i = 0; i < ranges.size(); i++ ) {
                BSONObj min = ranges[i].min;

                min = cm->getShardKey().extendRangeBound( min, false );

                if ( allChunkMinimums.count( min ) > 0 )
                    continue;

                didAnySplits = true;

                log() << "ns: " << ns << " need to split on "
                      << min << " because there is a range there" << endl;

                ChunkPtr c = cm->findIntersectingChunk( min );

                vector<BSONObj> splitPoints;
                splitPoints.push_back( min );

                BSONObj res;
                if ( !c->multiSplit( splitPoints, res ) ) {
                    error() << "split failed: " << res << endl;
                }
                else {
                    LOG(1) << "split worked: " << res << endl;
                }
                break;
            }

            if ( didAnySplits ) {
                // state change, just wait till next round
                continue;
            }

            CandidateChunk* p = _policy->balance( ns, status, _balancedLastTime );
            if ( p ) candidateChunks->push_back( CandidateChunkPtr( p ) );
        }
    }

    /**
     * Updates the remote cached version on the remote shard host (primary, in the case of replica
     * sets) if needed with a fully-qualified shard version for the given namespace:
     *   config server(s) + shard name + shard version
     *
     * If no remote cached version has ever been set, an initial shard version is sent.
     *
     * If the namespace is empty and no version has ever been sent, the config server + shard name
     * is sent to the remote shard host to initialize the connection as coming from mongos.
     * NOTE: This initialization is *best-effort only*.  Operations which wish to correctly version
     * must send the namespace.
     *
     * Config servers are special and are not (unless otherwise a shard) kept up to date with this
     * protocol.  This is safe so long as config servers only contain unversioned collections.
     *
     * It is an error to call checkShardVersion with an unversionable connection (isVersionableCB).
     *
     * @return true if we contacted the remote host
     */
    bool checkShardVersion( DBClientBase * conn_in , const string& ns , ChunkManagerPtr refManager, bool authoritative , int tryNumber ) {
        // TODO: cache, optimize, etc...

        // Empty namespaces are special - we require initialization but not versioning
        if (ns.size() == 0) {
            return initShardVersionEmptyNS(conn_in);
        }

        DBConfigPtr conf = grid.getDBConfig( ns );
        if ( ! conf )
            return false;

        DBClientBase* conn = getVersionable( conn_in );
        verify(conn); // errors thrown above

        unsigned long long officialSequenceNumber = 0;

        ShardPtr primary;
        ChunkManagerPtr manager;
        if (authoritative)
            conf->getChunkManagerIfExists(ns, true);

        conf->getChunkManagerOrPrimary(ns, manager, primary);

        if (manager)
            officialSequenceNumber = manager->getSequenceNumber();

        // Check this manager against the reference manager
        if( manager ){

            Shard shard = Shard::make( conn->getServerAddress() );
            if (refManager && !refManager->compatibleWith(*manager, shard.getName())) {
                const ChunkVersion refVersion(refManager->getVersion(shard.getName()));
                const ChunkVersion currentVersion(manager->getVersion(shard.getName()));
                string msg(str::stream() << "manager ("
                        << currentVersion.toString()
                        << " : " << manager->getSequenceNumber() << ") "
                        << "not compatible with reference manager ("
                        << refVersion.toString()
                        << " : " << refManager->getSequenceNumber() << ") "
                        << "on shard " << shard.getName()
                        << " (" << shard.getAddress().toString() << ")");

                throw SendStaleConfigException(ns,
                                               msg,
                                               refVersion,
                                               currentVersion);
            }
        }
        else if( refManager ){

            Shard shard = Shard::make(conn->getServerAddress());
            string msg( str::stream() << "not sharded ("
                        << ( (manager.get() == 0) ? string( "<none>" ) :
                                str::stream() << manager->getSequenceNumber() )
                        << ") but has reference manager ("
                        << refManager->getSequenceNumber() << ") "
                        << "on conn " << conn->getServerAddress() << " ("
                        << conn_in->getServerAddress() << ")" );

            throw SendStaleConfigException(ns,
                                           msg,
                                           refManager->getVersion(shard.getName()),
                                           ChunkVersion::UNSHARDED());
        }

        // Do not send setShardVersion to collections on the config servers - this causes problems
        // when config servers are also shards and get SSV with conflicting names.
        // TODO: Make config servers regular shards
        if (primary && primary->getName() == "config") {
            return false;
        }

        // Has the ChunkManager been reloaded since the last time we updated the shard version over
        // this connection?  If we've never updated the shard version, do so now.
        unsigned long long sequenceNumber = 0;
        if (connectionShardStatus.getSequence(conn, ns, &sequenceNumber)) {
            if (sequenceNumber == officialSequenceNumber) {
                return false;
            }
        }
//.........这里部分代码省略.........

//.........这里部分代码省略.........
                    }
                    else if( lastNeededVersion ) {

                        log() << "new version change detected to " << needVersion.toString()
                              << ", " << lastNeededCount << " writebacks processed at "
                              << lastNeededVersion->toString() << endl;

                        lastNeededCount = 0;
                    }

                    //
                    // Set our lastNeededVersion for next time
                    //

                    lastNeededVersion.reset( new ChunkVersion( needVersion ) );
                    lastNeededCount++;

                    //
                    // Determine if we should reload, if so, reload
                    //

                    bool shouldReload = ! needVersion.isWriteCompatibleWith( currVersion ) &&
                                        ! alreadyReloaded;

                    if( shouldReload && currVersion.isSet()
                                     && needVersion.isSet()
                                     && currVersion.hasCompatibleEpoch( needVersion ) )
                    {

                        //
                        // If we disagree about versions only, reload the chunk manager
                        //

                        db->getChunkManagerIfExists( ns, true );
                    }
                    else if( shouldReload ){

                        //
                        // If we disagree about anything else, reload the full db
                        //

                        warning() << "reloading config data for " << db->getName() << ", "
                                  << "wanted version " << needVersion.toString()
                                  << " but currently have version " << currVersion.toString() << endl;

                        db->reload();
                    }

                    // do request and then call getLastError
                    // we have to call getLastError so we can return the right fields to the user if they decide to call getLastError

                    BSONObj gle;
                    int attempts = 0;
                    while ( true ) {
                        attempts++;

                        try {

                            Request r( msg , 0 );
                            r.init();

                            r.d().reservedField() |= Reserved_FromWriteback;

                            ClientInfo * ci = r.getClientInfo();
                            if (!noauth) {
                                ci->getAuthorizationManager()->grantInternalAuthorization(

    /**
     * @return true if had to do something
     */
    bool checkShardVersion( DBClientBase& conn_in , const string& ns , bool authoritative , int tryNumber ) {
        // TODO: cache, optimize, etc...

        WriteBackListener::init( conn_in );

        DBConfigPtr conf = grid.getDBConfig( ns );
        if ( ! conf )
            return false;

        DBClientBase* conn = getVersionable( &conn_in );
        assert(conn); // errors thrown above

        unsigned long long officialSequenceNumber = 0;

        ChunkManagerPtr manager;
        const bool isSharded = conf->isSharded( ns );
        if ( isSharded ) {
            manager = conf->getChunkManagerIfExists( ns , authoritative );
            // It's possible the chunk manager was reset since we checked whether sharded was true,
            // so must check this here.
            if( manager ) officialSequenceNumber = manager->getSequenceNumber();
        }

        // has the ChunkManager been reloaded since the last time we updated the connection-level version?
        // (ie., last time we issued the setShardVersions below)
        unsigned long long sequenceNumber = connectionShardStatus.getSequence(conn,ns);
        if ( sequenceNumber == officialSequenceNumber ) {
            return false;
        }


        ShardChunkVersion version = 0;
        if ( isSharded && manager ) {
            version = manager->getVersion( Shard::make( conn->getServerAddress() ) );
        }

        if( version == 0 ){
            LOG(0) << "resetting shard version of " << ns << " on " << conn->getServerAddress() << ", " <<
                      ( ! isSharded ? "no longer sharded" :
                      ( ! manager ? "no chunk manager found" :
                                    "version is zero" ) ) << endl;
        }


        LOG(2) << " have to set shard version for conn: " << conn << " ns:" << ns
               << " my last seq: " << sequenceNumber << "  current: " << officialSequenceNumber
               << " version: " << version << " manager: " << manager.get()
               << endl;

        BSONObj result;
        if ( setShardVersion( *conn , ns , version , authoritative , result ) ) {
            // success!
            LOG(1) << "      setShardVersion success: " << result << endl;
            connectionShardStatus.setSequence( conn , ns , officialSequenceNumber );
            return true;
        }

        LOG(1) << "       setShardVersion failed!\n" << result << endl;

        if ( result["need_authoritative"].trueValue() )
            massert( 10428 ,  "need_authoritative set but in authoritative mode already" , ! authoritative );

        if ( ! authoritative ) {
            checkShardVersion( *conn , ns , 1 , tryNumber + 1 );
            return true;
        }
        
        if ( result["reloadConfig"].trueValue() ) {
            if( result["version"].timestampTime() == 0 ){
                // reload db
                conf->reload();
            }
            else {
                // reload config
                conf->getChunkManager( ns , true );
            }
        }

        const int maxNumTries = 7;
        if ( tryNumber < maxNumTries ) {
            LOG( tryNumber < ( maxNumTries / 2 ) ? 1 : 0 ) 
                << "going to retry checkShardVersion host: " << conn->getServerAddress() << " " << result << endl;
            sleepmillis( 10 * tryNumber );
            checkShardVersion( *conn , ns , true , tryNumber + 1 );
            return true;
        }
        
        string errmsg = str::stream() << "setShardVersion failed host: " << conn->getServerAddress() << " " << result;
        log() << "     " << errmsg << endl;
        massert( 10429 , errmsg , 0 );
        return true;
    }

//.........这里部分代码省略.........

            set<BSONObj> allChunkMinimums;

            while ( cursor->more() ) {
                BSONObj chunk = cursor->nextSafe().getOwned();
                vector<BSONObj>& chunks = shardToChunksMap[chunk[ChunkType::shard()].String()];
                allChunkMinimums.insert( chunk[ChunkType::min()].Obj() );
                chunks.push_back( chunk );
            }
            cursor.reset();

            if (shardToChunksMap.empty()) {
                LOG(1) << "skipping empty collection (" << ns << ")";
                continue;
            }

            for ( vector<Shard>::iterator i=allShards.begin(); i!=allShards.end(); ++i ) {
                // this just makes sure there is an entry in shardToChunksMap for every shard
                Shard s = *i;
                shardToChunksMap[s.getName()].size();
            }

            DistributionStatus status( shardInfo, shardToChunksMap );

            // load tags
            conn.ensureIndex(TagsType::ConfigNS,
                             BSON(TagsType::ns() << 1 << TagsType::min() << 1),
                             true);

            cursor = conn.query(TagsType::ConfigNS,
                                QUERY(TagsType::ns(ns)).sort(TagsType::min()));

            vector<TagRange> ranges;

            while ( cursor->more() ) {
                BSONObj tag = cursor->nextSafe();
                TagRange tr(tag[TagsType::min()].Obj().getOwned(),
                            tag[TagsType::max()].Obj().getOwned(),
                            tag[TagsType::tag()].String());
                ranges.push_back(tr);
                uassert(16356,
                        str::stream() << "tag ranges not valid for: " << ns,
                        status.addTagRange(tr) );

            }
            cursor.reset();

            DBConfigPtr cfg = grid.getDBConfig( ns );
            if ( !cfg ) {
                warning() << "could not load db config to balance " << ns << " collection" << endl;
                continue;
            }

            // This line reloads the chunk manager once if this process doesn't know the collection
            // is sharded yet.
            ChunkManagerPtr cm = cfg->getChunkManagerIfExists( ns, true );
            if ( !cm ) {
                warning() << "could not load chunks to balance " << ns << " collection" << endl;
                continue;
            }

            // loop through tags to make sure no chunk spans tags; splits on tag min. for all chunks
            bool didAnySplits = false;
            for ( unsigned i = 0; i < ranges.size(); i++ ) {
                BSONObj min = ranges[i].min;

                min = cm->getShardKey().extendRangeBound( min, false );

                if ( allChunkMinimums.count( min ) > 0 )
                    continue;

                didAnySplits = true;

                log() << "ns: " << ns << " need to split on "
                      << min << " because there is a range there" << endl;

                ChunkPtr c = cm->findIntersectingChunk( min );

                vector<BSONObj> splitPoints;
                splitPoints.push_back( min );

                BSONObj res;
                if ( !c->multiSplit( splitPoints, res ) ) {
                    error() << "split failed: " << res << endl;
                }
                else {
                    LOG(1) << "split worked: " << res << endl;
                }
                break;
            }

            if ( didAnySplits ) {
                // state change, just wait till next round
                continue;
            }

            CandidateChunk* p = _policy->balance( ns, status, _balancedLastTime );
            if ( p ) candidateChunks->push_back( CandidateChunkPtr( p ) );
        }
    }