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

    void Strategy::getMore( Request& r ) {

        Timer getMoreTimer;

        const char *ns = r.getns();

        // TODO:  Handle stale config exceptions here from coll being dropped or sharded during op
        // for now has same semantics as legacy request
        DBConfigPtr config = grid.getDBConfig( ns );
        ShardPtr primary;
        ChunkManagerPtr info;
        config->getChunkManagerOrPrimary( ns, info, primary );

        //
        // TODO: Cleanup cursor cache, consolidate into single codepath
        //

        int ntoreturn = r.d().pullInt();
        long long id = r.d().pullInt64();
        string host = cursorCache.getRef( id );
        ShardedClientCursorPtr cursor = cursorCache.get( id );
        int cursorMaxTimeMS = cursorCache.getMaxTimeMS( id );

        // Cursor ids should not overlap between sharded and unsharded cursors
        massert( 17012, str::stream() << "duplicate sharded and unsharded cursor id "
                                      << id << " detected for " << ns
                                      << ", duplicated on host " << host,
                 NULL == cursorCache.get( id ).get() || host.empty() );

        ClientBasic* client = ClientBasic::getCurrent();
        NamespaceString nsString(ns);
        AuthorizationSession* authSession = client->getAuthorizationSession();
        Status status = authSession->checkAuthForGetMore( nsString, id );
        audit::logGetMoreAuthzCheck( client, nsString, id, status.code() );
        uassertStatusOK(status);

        if( !host.empty() ){

            LOG(3) << "single getmore: " << ns << endl;

            // we used ScopedDbConnection because we don't get about config versions
            // not deleting data is handled elsewhere
            // and we don't want to call setShardVersion
            ScopedDbConnection conn(host);

            Message response;
            bool ok = conn->callRead( r.m() , response);
            uassert( 10204 , "dbgrid: getmore: error calling db", ok);

            bool hasMore = (response.singleData()->getCursor() != 0);

            if ( !hasMore ) {
                cursorCache.removeRef( id );
            }

            r.reply( response , "" /*conn->getServerAddress() */ );
            conn.done();
            return;
        }
        else if ( cursor ) {

            if ( cursorMaxTimeMS == kMaxTimeCursorTimeLimitExpired ) {
                cursorCache.remove( id );
                uasserted( ErrorCodes::ExceededTimeLimit, "operation exceeded time limit" );
            }

            // TODO: Try to match logic of mongod, where on subsequent getMore() we pull lots more data?
            BufBuilder buffer( ShardedClientCursor::INIT_REPLY_BUFFER_SIZE );
            int docCount = 0;
            const int startFrom = cursor->getTotalSent();
            bool hasMore = cursor->sendNextBatch( r, ntoreturn, buffer, docCount );

            if ( hasMore ) {
                // still more data
                cursor->accessed();

                if ( cursorMaxTimeMS != kMaxTimeCursorNoTimeLimit ) {
                    // Update remaining amount of time in cursor cache.
                    int cursorLeftoverMillis = cursorMaxTimeMS - getMoreTimer.millis();
                    if ( cursorLeftoverMillis <= 0 ) {
                        cursorLeftoverMillis = kMaxTimeCursorTimeLimitExpired;
                    }
                    cursorCache.updateMaxTimeMS( id, cursorLeftoverMillis );
                }
            }
            else {
                // we've exhausted the cursor
                cursorCache.remove( id );
            }

            replyToQuery( 0, r.p(), r.m(), buffer.buf(), buffer.len(), docCount,
                    startFrom, hasMore ? cursor->getId() : 0 );
            return;
        }
        else {

            LOG( 3 ) << "could not find cursor " << id << " in cache for " << ns << endl;

            replyToQuery( ResultFlag_CursorNotFound , r.p() , r.m() , 0 , 0 , 0 );
            return;
//.........这里部分代码省略.........

    void WriteBackListener::run() {

        int secsToSleep = 0;
        scoped_ptr<ChunkVersion> lastNeededVersion;
        int lastNeededCount = 0;
        bool needsToReloadShardInfo = false;

        while ( ! inShutdown() ) {

            if ( ! Shard::isAShardNode( _addr ) ) {
                LOG(1) << _addr << " is not a shard node" << endl;
                sleepsecs( 60 );
                continue;
            }

            try {
                if (needsToReloadShardInfo) {
                    // It's possible this shard was removed
                    Shard::reloadShardInfo();
                    needsToReloadShardInfo = false;
                }

                ScopedDbConnection conn(_addr);

                BSONObj result;

                {
                    BSONObjBuilder cmd;
                    cmd.appendOID( "writebacklisten" , &serverID ); // Command will block for data
                    if ( ! conn->runCommand( "admin" , cmd.obj() , result ) ) {
                        result = result.getOwned();
                        log() <<  "writebacklisten command failed!  "  << result << endl;
                        conn.done();
                        continue;
                    }

                }
                conn.done();

                LOG(1) << "writebacklisten result: " << result << endl;

                BSONObj data = result.getObjectField( "data" );
                if ( data.getBoolField( "writeBack" ) ) {
                    string ns = data["ns"].valuestrsafe();

                    ConnectionIdent cid( "" , 0 );
                    OID wid;
                    if ( data["connectionId"].isNumber() && data["id"].type() == jstOID ) {
                        string s = "";
                        if ( data["instanceIdent"].type() == String )
                            s = data["instanceIdent"].String();
                        cid = ConnectionIdent( s , data["connectionId"].numberLong() );
                        wid = data["id"].OID();
                    }
                    else {
                        warning() << "mongos/mongod version mismatch (1.7.5 is the split)" << endl;
                    }

                    int len; // not used, but needed for next call
                    Message msg( (void*)data["msg"].binData( len ) , false );
                    massert( 10427 ,  "invalid writeback message" , msg.header()->valid() );

                    DBConfigPtr db = grid.getDBConfig( ns );
                    ChunkVersion needVersion = ChunkVersion::fromBSON( data, "version" );

                    //
                    // TODO: Refactor the sharded strategy to correctly handle all sharding state changes itself,
                    // we can't rely on WBL to do this for us b/c anything could reset our state in-between.
                    // We should always reload here for efficiency when possible, but staleness is also caught in the
                    // loop below.
                    //

                    ChunkManagerPtr manager;
                    ShardPtr primary;
                    db->getChunkManagerOrPrimary( ns, manager, primary );

                    ChunkVersion currVersion;
                    if( manager ) currVersion = manager->getVersion();

                    LOG(1) << "connectionId: " << cid << " writebackId: " << wid << " needVersion : " << needVersion.toString()
                           << " mine : " << currVersion.toString() << endl;

                    LOG(1) << msg.toString() << endl;

                    //
                    // We should reload only if we need to update our version to be compatible *and* we
                    // haven't already done so.  This avoids lots of reloading when we remove/add a sharded collection
                    //

                    bool alreadyReloaded = lastNeededVersion &&
                                           lastNeededVersion->isEquivalentTo( needVersion );

                    if( alreadyReloaded ){

                        LOG(1) << "wbl already reloaded config information for version "
                               << needVersion << ", at version " << currVersion << endl;
                    }
                    else if( lastNeededVersion ) {

                        log() << "new version change detected to " << needVersion.toString()
//.........这里部分代码省略.........