Imported Upstream version 2.2.0upstream/2.2.0

1 files changed, 1724 insertions, 0 deletions

diff --git a/src/mongo/client/parallel.cpp b/src/mongo/client/parallel.cpp
new file mode 100644
index 00000000000..a2461ed7ee3
--- /dev/null
+++ b/src/mongo/client/parallel.cpp
@@ -0,0 +1,1724 @@
+// parallel.cpp
+/*
+ *    Copyright 2010 10gen Inc.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+
+#include "pch.h"
+#include "parallel.h"
+#include "connpool.h"
+#include "../db/dbmessage.h"
+#include "../s/util.h"
+#include "../s/shard.h"
+#include "../s/chunk.h"
+#include "../s/config.h"
+#include "../s/grid.h"
+#include "mongo/client/dbclientcursor.h"
+
+namespace mongo {
+
+    LabeledLevel pc( "pcursor", 2 );
+
+    // --------  ClusteredCursor -----------
+
+    ClusteredCursor::ClusteredCursor( const QuerySpec& q ) {
+        _ns = q.ns();
+        _query = q.filter().copy();
+        _hint = q.hint();
+        _sort = q.sort();
+        _options = q.options();
+        _fields = q.fields().copy();
+        _batchSize = q.ntoreturn();
+        if ( _batchSize == 1 )
+            _batchSize = 2;
+        
+        _done = false;
+        _didInit = false;
+    }
+
+    ClusteredCursor::ClusteredCursor( QueryMessage& q ) {
+        _ns = q.ns;
+        _query = q.query.copy();
+        _options = q.queryOptions;
+        _fields = q.fields.copy();
+        _batchSize = q.ntoreturn;
+        if ( _batchSize == 1 )
+            _batchSize = 2;
+
+        _done = false;
+        _didInit = false;
+    }
+
+    ClusteredCursor::ClusteredCursor( const string& ns , const BSONObj& q , int options , const BSONObj& fields ) {
+        _ns = ns;
+        _query = q.getOwned();
+        _options = options;
+        _fields = fields.getOwned();
+        _batchSize = 0;
+
+        _done = false;
+        _didInit = false;
+    }
+
+    ClusteredCursor::~ClusteredCursor() {
+        _done = true; // just in case
+    }
+
+    void ClusteredCursor::init() {
+        if ( _didInit )
+            return;
+        _didInit = true;
+        _init();
+    }
+
+    void ClusteredCursor::_checkCursor( DBClientCursor * cursor ) {
+        verify( cursor );
+        
+        if ( cursor->hasResultFlag( ResultFlag_ShardConfigStale ) ) {
+            BSONObj error;
+            cursor->peekError( &error );
+            throw RecvStaleConfigException( "ClusteredCursor::_checkCursor", error );
+        }
+        
+        if ( cursor->hasResultFlag( ResultFlag_ErrSet ) ) {
+            BSONObj o = cursor->next();
+            throw UserException( o["code"].numberInt() , o["$err"].String() );
+        }
+
+        if ( NamespaceString( cursor->getns() ).isCommand() ) {
+            // For backwards compatibility with v2.0 mongods because in 2.0 commands that care about
+            // versioning (like the count command) will return with the stale config error code, but
+            // don't set the ShardConfigStale result flag on the cursor.
+            // TODO: This should probably be removed for 2.3, as we'll no longer need to support
+            // running with a 2.0 mongod.
+            BSONObj res = cursor->peekFirst();
+            if ( res.hasField( "code" ) && res["code"].Number() == SendStaleConfigCode ) {
+                throw RecvStaleConfigException( "ClusteredCursor::_checkCursor", res );
+            }
+        }
+    }
+
+    auto_ptr<DBClientCursor> ClusteredCursor::query( const string& server , int num , BSONObj extra , int skipLeft , bool lazy ) {
+        uassert( 10017 ,  "cursor already done" , ! _done );
+        verify( _didInit );
+
+        BSONObj q = _query;
+        if ( ! extra.isEmpty() ) {
+            q = concatQuery( q , extra );
+        }
+
+        try {
+            ShardConnection conn( server , _ns );
+            
+            if ( conn.setVersion() ) {
+                conn.done();
+                // Deprecated, so we don't care about versions here
+                throw RecvStaleConfigException( _ns , "ClusteredCursor::query" , ShardChunkVersion( 0, OID() ), ShardChunkVersion( 0, OID() ), true );
+            }
+            
+            LOG(5) << "ClusteredCursor::query (" << type() << ") server:" << server
+                   << " ns:" << _ns << " query:" << q << " num:" << num
+                   << " _fields:" << _fields << " options: " << _options << endl;
+        
+            auto_ptr<DBClientCursor> cursor =
+                conn->query( _ns , q , num , 0 , ( _fields.isEmpty() ? 0 : &_fields ) , _options , _batchSize == 0 ? 0 : _batchSize + skipLeft );
+            
+            if ( ! cursor.get() && _options & QueryOption_PartialResults ) {
+                _done = true;
+                conn.done();
+                return cursor;
+            }
+            
+            massert( 13633 , str::stream() << "error querying server: " << server  , cursor.get() );
+            
+            cursor->attach( &conn ); // this calls done on conn
+            verify( ! conn.ok() );
+            _checkCursor( cursor.get() );
+            return cursor;
+        }
+        catch ( SocketException& e ) {
+            if ( ! ( _options & QueryOption_PartialResults ) )
+                throw e;
+            _done = true;
+            return auto_ptr<DBClientCursor>();
+        }
+    }
+
+    BSONObj ClusteredCursor::explain( const string& server , BSONObj extra ) {
+        BSONObj q = _query;
+        if ( ! extra.isEmpty() ) {
+            q = concatQuery( q , extra );
+        }
+        
+        Query qu( q );
+        qu.explain();
+        if ( ! _hint.isEmpty() )
+            qu.hint( _hint );
+        if ( ! _sort.isEmpty() )
+            qu.sort( _sort );
+
+        BSONObj o;
+
+        ShardConnection conn( server , _ns );
+        auto_ptr<DBClientCursor> cursor = conn->query( _ns , qu , abs( _batchSize ) * -1 , 0 , _fields.isEmpty() ? 0 : &_fields );
+        if ( cursor.get() && cursor->more() )
+            o = cursor->next().getOwned();
+        conn.done();
+        return o;
+    }
+
+    BSONObj ClusteredCursor::concatQuery( const BSONObj& query , const BSONObj& extraFilter ) {
+        if ( ! query.hasField( "query" ) )
+            return _concatFilter( query , extraFilter );
+
+        BSONObjBuilder b;
+        BSONObjIterator i( query );
+        while ( i.more() ) {
+            BSONElement e = i.next();
+
+            if ( strcmp( e.fieldName() , "query" ) ) {
+                b.append( e );
+                continue;
+            }
+
+            b.append( "query" , _concatFilter( e.embeddedObjectUserCheck() , extraFilter ) );
+        }
+        return b.obj();
+    }
+
+    BSONObj ClusteredCursor::_concatFilter( const BSONObj& filter , const BSONObj& extra ) {
+        BSONObjBuilder b;
+        b.appendElements( filter );
+        b.appendElements( extra );
+        return b.obj();
+        // TODO: should do some simplification here if possibl ideally
+    }
+
+    void ParallelSortClusteredCursor::explain(BSONObjBuilder& b) {
+        // Note: by default we filter out allPlans and oldPlan in the shell's
+        // explain() function. If you add any recursive structures, make sure to
+        // edit the JS to make sure everything gets filtered.
+
+        // Return single shard output if we're versioned but not sharded, or
+        // if we specified only a single shard
+        // TODO:  We should really make this simpler - all queries via mongos
+        // *always* get the same explain format
+        if( ( isVersioned() && ! isSharded() ) || _qShards.size() == 1 ){
+            map<string,list<BSONObj> > out;
+            _explain( out );
+            verify( out.size() == 1 );
+            list<BSONObj>& l = out.begin()->second;
+            verify( l.size() == 1 );
+            b.appendElements( *(l.begin()) );
+            return;
+        }
+
+        b.append( "clusteredType" , type() );
+
+        string cursorType;
+        BSONObj indexBounds;
+        BSONObj oldPlan;
+        
+        long long millis = 0;
+        double numExplains = 0;
+
+        map<string,long long> counters;
+        
+        map<string,list<BSONObj> > out;
+        {
+            _explain( out );
+
+            BSONObjBuilder x( b.subobjStart( "shards" ) );
+            for ( map<string,list<BSONObj> >::iterator i=out.begin(); i!=out.end(); ++i ) {
+                string shard = i->first;
+                list<BSONObj> l = i->second;
+                BSONArrayBuilder y( x.subarrayStart( shard ) );
+                for ( list<BSONObj>::iterator j=l.begin(); j!=l.end(); ++j ) {
+                    BSONObj temp = *j;
+                    y.append( temp );
+
+                    BSONObjIterator k( temp );
+                    while ( k.more() ) {
+                        BSONElement z = k.next();
+                        if ( z.fieldName()[0] != 'n' )
+                            continue;
+                        long long& c = counters[z.fieldName()];
+                        c += z.numberLong();
+                    }
+
+                    millis += temp["millis"].numberLong();
+                    numExplains++;
+
+                    if ( temp["cursor"].type() == String ) { 
+                        if ( cursorType.size() == 0 )
+                            cursorType = temp["cursor"].String();
+                        else if ( cursorType != temp["cursor"].String() )
+                            cursorType = "multiple";
+                    }
+
+                    if ( temp["indexBounds"].type() == Object )
+                        indexBounds = temp["indexBounds"].Obj();
+
+                    if ( temp["oldPlan"].type() == Object )
+                        oldPlan = temp["oldPlan"].Obj();
+
+                }
+                y.done();
+            }
+            x.done();
+        }
+
+        b.append( "cursor" , cursorType );
+        for ( map<string,long long>::iterator i=counters.begin(); i!=counters.end(); ++i )
+            b.appendNumber( i->first , i->second );
+
+        b.appendNumber( "millisShardTotal" , millis );
+        b.append( "millisShardAvg" , 
+                  numExplains ? static_cast<int>( static_cast<double>(millis) / numExplains )
+                  : 0 );
+        b.append( "numQueries" , (int)numExplains );
+        b.append( "numShards" , (int)out.size() );
+
+        if ( out.size() == 1 ) {
+            b.append( "indexBounds" , indexBounds );
+            if ( ! oldPlan.isEmpty() ) {
+                // this is to stay in compliance with mongod behavior
+                // we should make this cleaner, i.e. {} == nothing
+                b.append( "oldPlan" , oldPlan );
+            }
+        }
+        else {
+            // TODO: this is lame...
+        }
+
+    }
+
+    // --------  FilteringClientCursor -----------
+    FilteringClientCursor::FilteringClientCursor( const BSONObj filter )
+        : _matcher( filter ) , _pcmData( NULL ), _done( true ) {
+    }
+
+    FilteringClientCursor::FilteringClientCursor( auto_ptr<DBClientCursor> cursor , const BSONObj filter )
+        : _matcher( filter ) , _cursor( cursor ) , _pcmData( NULL ), _done( cursor.get() == 0 ) {
+    }
+
+    FilteringClientCursor::FilteringClientCursor( DBClientCursor* cursor , const BSONObj filter )
+        : _matcher( filter ) , _cursor( cursor ) , _pcmData( NULL ), _done( cursor == 0 ) {
+    }
+
+
+    FilteringClientCursor::~FilteringClientCursor() {
+        // Don't use _pcmData
+        _pcmData = NULL;
+    }
+
+    void FilteringClientCursor::reset( auto_ptr<DBClientCursor> cursor ) {
+        _cursor = cursor;
+        _next = BSONObj();
+        _done = _cursor.get() == 0;
+        _pcmData = NULL;
+    }
+
+    void FilteringClientCursor::reset( DBClientCursor* cursor, ParallelConnectionMetadata* pcmData ) {
+        _cursor.reset( cursor );
+        _pcmData = pcmData;
+        _next = BSONObj();
+        _done = cursor == 0;
+    }
+
+
+    bool FilteringClientCursor::more() {
+        if ( ! _next.isEmpty() )
+            return true;
+
+        if ( _done )
+            return false;
+
+        _advance();
+        return ! _next.isEmpty();
+    }
+
+    BSONObj FilteringClientCursor::next() {
+        verify( ! _next.isEmpty() );
+        verify( ! _done );
+
+        BSONObj ret = _next;
+        _next = BSONObj();
+        _advance();
+        return ret;
+    }
+
+    BSONObj FilteringClientCursor::peek() {
+        if ( _next.isEmpty() )
+            _advance();
+        return _next;
+    }
+
+    void FilteringClientCursor::_advance() {
+        verify( _next.isEmpty() );
+        if ( ! _cursor.get() || _done )
+            return;
+
+        while ( _cursor->more() ) {
+            _next = _cursor->next();
+            if ( _matcher.matches( _next ) ) {
+                if ( ! _cursor->moreInCurrentBatch() )
+                    _next = _next.getOwned();
+                return;
+            }
+            _next = BSONObj();
+        }
+        _done = true;
+    }
+
+    // --------  SerialServerClusteredCursor -----------
+
+    SerialServerClusteredCursor::SerialServerClusteredCursor( const set<ServerAndQuery>& servers , QueryMessage& q , int sortOrder) : ClusteredCursor( q ) {
+        for ( set<ServerAndQuery>::const_iterator i = servers.begin(); i!=servers.end(); i++ )
+            _servers.push_back( *i );
+
+        if ( sortOrder > 0 )
+            sort( _servers.begin() , _servers.end() );
+        else if ( sortOrder < 0 )
+            sort( _servers.rbegin() , _servers.rend() );
+
+        _serverIndex = 0;
+
+        _needToSkip = q.ntoskip;
+    }
+
+    bool SerialServerClusteredCursor::more() {
+
+        // TODO: optimize this by sending on first query and then back counting
+        //       tricky in case where 1st server doesn't have any after
+        //       need it to send n skipped
+        while ( _needToSkip > 0 && _current.more() ) {
+            _current.next();
+            _needToSkip--;
+        }
+
+        if ( _current.more() )
+            return true;
+
+        if ( _serverIndex >= _servers.size() ) {
+            return false;
+        }
+
+        ServerAndQuery& sq = _servers[_serverIndex++];
+
+        _current.reset( query( sq._server , 0 , sq._extra ) );
+        return more();
+    }
+
+    BSONObj SerialServerClusteredCursor::next() {
+        uassert( 10018 ,  "no more items" , more() );
+        return _current.next();
+    }
+
+    void SerialServerClusteredCursor::_explain( map< string,list<BSONObj> >& out ) {
+        for ( unsigned i=0; i<_servers.size(); i++ ) {
+            ServerAndQuery& sq = _servers[i];
+            list<BSONObj> & l = out[sq._server];
+            l.push_back( explain( sq._server , sq._extra ) );
+        }
+    }
+
+    // --------  ParallelSortClusteredCursor -----------
+
+    ParallelSortClusteredCursor::ParallelSortClusteredCursor( const set<ServerAndQuery>& servers , QueryMessage& q ,
+            const BSONObj& sortKey )
+        : ClusteredCursor( q ) , _servers( servers ) {
+        _sortKey = sortKey.getOwned();
+        _needToSkip = q.ntoskip;
+        _finishCons();
+    }
+
+    ParallelSortClusteredCursor::ParallelSortClusteredCursor( const set<ServerAndQuery>& servers , const string& ns ,
+            const Query& q ,
+            int options , const BSONObj& fields  )
+        : ClusteredCursor( ns , q.obj , options , fields ) , _servers( servers ) {
+        _sortKey = q.getSort().copy();
+        _needToSkip = 0;
+        _finishCons();
+    }
+
+    ParallelSortClusteredCursor::ParallelSortClusteredCursor( const QuerySpec& qSpec, const CommandInfo& cInfo )
+        : ClusteredCursor( qSpec ),
+          _qSpec( qSpec ), _cInfo( cInfo ), _totalTries( 0 )
+    {
+        _finishCons();
+    }
+
+    ParallelSortClusteredCursor::ParallelSortClusteredCursor( const set<Shard>& qShards, const QuerySpec& qSpec )
+        : ClusteredCursor( qSpec ),
+          _qSpec( qSpec ), _totalTries( 0 )
+    {
+        for( set<Shard>::const_iterator i = qShards.begin(), end = qShards.end(); i != end; ++i )
+            _qShards.insert( *i );
+
+        _finishCons();
+    }
+
+    void ParallelSortClusteredCursor::_finishCons() {
+        _numServers = _servers.size();
+        _lastFrom = 0;
+        _cursors = 0;
+
+        if( ! _qSpec.isEmpty() ){
+
+            _needToSkip = _qSpec.ntoskip();
+            _cursors = 0;
+            _sortKey = _qSpec.sort();
+            _fields = _qSpec.fields();
+
+            if( ! isVersioned() ) verify( _cInfo.isEmpty() );
+        }
+
+        if ( ! _sortKey.isEmpty() && ! _fields.isEmpty() ) {
+            // we need to make sure the sort key is in the projection
+
+            set<string> sortKeyFields;
+            _sortKey.getFieldNames(sortKeyFields);
+
+            BSONObjBuilder b;
+            bool isNegative = false;
+            {
+                BSONObjIterator i( _fields );
+                while ( i.more() ) {
+                    BSONElement e = i.next();
+                    b.append( e );
+
+                    string fieldName = e.fieldName();
+
+                    // exact field
+                    bool found = sortKeyFields.erase(fieldName);
+
+                    // subfields
+                    set<string>::const_iterator begin = sortKeyFields.lower_bound(fieldName + ".\x00");
+                    set<string>::const_iterator end   = sortKeyFields.lower_bound(fieldName + ".\xFF");
+                    sortKeyFields.erase(begin, end);
+
+                    if ( ! e.trueValue() ) {
+                        uassert( 13431 , "have to have sort key in projection and removing it" , !found && begin == end );
+                    }
+                    else if (!e.isABSONObj()) {
+                        isNegative = true;
+                    }
+                }
+            }
+
+            if (isNegative) {
+                for (set<string>::const_iterator it(sortKeyFields.begin()), end(sortKeyFields.end()); it != end; ++it) {
+                    b.append(*it, 1);
+                }
+            }
+
+            _fields = b.obj();
+        }
+
+        if( ! _qSpec.isEmpty() ){
+            _qSpec.setFields( _fields );
+        }
+    }
+
+    void ParallelConnectionMetadata::cleanup( bool full ){
+
+        if( full || errored ) retryNext = false;
+
+        if( ! retryNext && pcState ){
+
+            if( errored && pcState->conn ){
+                // Don't return this conn to the pool if it's bad
+                pcState->conn->kill();
+                pcState->conn.reset();
+            }
+            else if( initialized ){
+
+                verify( pcState->cursor );
+                verify( pcState->conn );
+
+                if( ! finished && pcState->conn->ok() ){
+                    try{
+                        // Complete the call if only halfway done
+                        bool retry = false;
+                        pcState->cursor->initLazyFinish( retry );
+                    }
+                    catch( std::exception& ){
+                        warning() << "exception closing cursor" << endl;
+                    }
+                    catch( ... ){
+                        warning() << "unknown exception closing cursor" << endl;
+                    }
+                }
+            }
+
+            // Double-check conn is closed
+            if( pcState->conn ){
+                pcState->conn->done();
+            }
+
+            pcState.reset();
+        }
+        else verify( finished || ! initialized );
+
+        initialized = false;
+        finished = false;
+        completed = false;
+        errored = false;
+    }
+
+
+
+    BSONObj ParallelConnectionState::toBSON() const {
+
+        BSONObj cursorPeek = BSON( "no cursor" << "" );
+        if( cursor ){
+            vector<BSONObj> v;
+            cursor->peek( v, 1 );
+            if( v.size() == 0 ) cursorPeek = BSON( "no data" << "" );
+            else cursorPeek = BSON( "" << v[0] );
+        }
+
+        BSONObj stateObj =
+                BSON( "conn" << ( conn ? ( conn->ok() ? conn->conn().toString() : "(done)" ) : "" ) <<
+                      "vinfo" << ( manager ? ( str::stream() << manager->getns() << " @ " << manager->getVersion().toString() ) :
+                                               primary->toString() ) );
+
+        // Append cursor data if exists
+        BSONObjBuilder stateB;
+        stateB.appendElements( stateObj );
+        if( ! cursor ) stateB.append( "cursor", "(none)" );
+        else {
+            vector<BSONObj> v;
+            cursor->peek( v, 1 );
+            if( v.size() == 0 ) stateB.append( "cursor", "(empty)" );
+            else stateB.append( "cursor", v[0] );
+        }
+
+        stateB.append( "count", count );
+        stateB.append( "done", done );
+
+        return stateB.obj().getOwned();
+    }
+
+    BSONObj ParallelConnectionMetadata::toBSON() const {
+        return BSON( "state" << ( pcState ? pcState->toBSON() : BSONObj() ) <<
+                     "retryNext" << retryNext <<
+                     "init" << initialized <<
+                     "finish" << finished <<
+                     "errored" << errored );
+    }
+
+    BSONObj ParallelSortClusteredCursor::toBSON() const {
+
+        BSONObjBuilder b;
+
+        b.append( "tries", _totalTries );
+
+        {
+            BSONObjBuilder bb;
+            for( map< Shard, PCMData >::const_iterator i = _cursorMap.begin(), end = _cursorMap.end(); i != end; ++i ){
+                bb.append( i->first.toString(), i->second.toBSON() );
+            }
+            b.append( "cursors", bb.obj().getOwned() );
+        }
+
+        {
+            BSONObjBuilder bb;
+            for( map< string, int >::const_iterator i = _staleNSMap.begin(), end = _staleNSMap.end(); i != end; ++i ){
+                bb.append( i->first, i->second );
+            }
+            b.append( "staleTries", bb.obj().getOwned() );
+        }
+
+        return b.obj().getOwned();
+    }
+
+    string ParallelSortClusteredCursor::toString() const {
+        return str::stream() << "PCursor : " << toBSON();
+    }
+
+    void ParallelSortClusteredCursor::fullInit(){
+        startInit();
+        finishInit();
+    }
+
+    void ParallelSortClusteredCursor::_markStaleNS( const NamespaceString& staleNS, const StaleConfigException& e, bool& forceReload, bool& fullReload ){
+
+        fullReload = e.requiresFullReload();
+
+        if( _staleNSMap.find( staleNS ) == _staleNSMap.end() ) _staleNSMap[ staleNS ] = 1;
+
+        int tries = ++_staleNSMap[ staleNS ];
+
+        if( tries >= 5 ) throw SendStaleConfigException( staleNS, str::stream() << "too many retries of stale version info",
+                                                         e.getVersionReceived(), e.getVersionWanted() );
+
+        forceReload = tries > 2;
+    }
+
+    void ParallelSortClusteredCursor::_handleStaleNS( const NamespaceString& staleNS, bool forceReload, bool fullReload ){
+
+        DBConfigPtr config = grid.getDBConfig( staleNS.db );
+
+        // Reload db if needed, make sure it works
+        if( config && fullReload && ! config->reload() ){
+            // We didn't find the db after the reload, the db may have been dropped,
+            // reset this ptr
+            config.reset();
+        }
+
+        if( ! config ){
+            warning() << "cannot reload database info for stale namespace " << staleNS << endl;
+        }
+        else {
+            // Reload chunk manager, potentially forcing the namespace
+            config->getChunkManagerIfExists( staleNS, true, forceReload );
+        }
+
+    }
+
+    void ParallelSortClusteredCursor::setupVersionAndHandleSlaveOk(
+        PCStatePtr state,
+        const Shard& shard,
+        ShardPtr primary,
+        const NamespaceString& ns,
+        const string& vinfo,
+        ChunkManagerPtr manager ) {
+
+        if ( manager ) {
+            state->manager = manager;
+        }
+        else if ( primary ) {
+            state->primary = primary;
+        }
+
+        verify( ! primary || shard == *primary || ! isVersioned() );
+
+        // Setup conn
+        if ( !state->conn ){
+            state->conn.reset( new ShardConnection( shard, ns, manager ) );
+        }
+
+        const DBClientBase* rawConn = state->conn->getRawConn();
+        if (( _options & QueryOption_SlaveOk ) &&
+                rawConn->type() == ConnectionString::SET &&
+                rawConn->isFailed() ) {
+            /* A side effect of this short circuiting is this will not be
+             * able figure out that the primary is now up on it's own and
+             * has to rely on other threads to refresh the node states.
+             */
+
+            OCCASIONALLY {
+                const DBClientReplicaSet* repl =
+                    dynamic_cast<const DBClientReplicaSet*>( rawConn );
+                warning() << "Primary for " << repl->getServerAddress()
+                          << " was down before, bypassing setShardVersion."
+                          << " Local config view can be stale." << endl;
+            }
+        } else {
+            try {
+                /* TODO: Undo SERVER-5797. This try-catch is a temporary hack until
+                 * secondaries can properly handle shard versioning
+                 */
+                if ( state->conn->setVersion() ) {
+                    // It's actually okay if we set the version here, since either the
+                    // manager will be verified as compatible, or if the manager doesn't
+                    // exist, we don't care about version consistency
+                    log( pc ) << "needed to set remote version on connection to value "
+                              << "compatible with " << vinfo << endl;
+                }
+            } catch ( const DBException& dbEx ) {
+                if ( (dbEx.getCode() == 10009 /* no master */ &&
+                        ( _options & QueryOption_SlaveOk )) ) {
+
+                    OCCASIONALLY {
+                        const DBClientReplicaSet* repl =
+                            dynamic_cast<const DBClientReplicaSet*>(
+                                    state->conn->getRawConn() );
+
+                        warning() << "Cannot contact primary for "
+                                  << repl->getServerAddress()
+                                  << " to check shard version. "
+                                  << "SlaveOk query can be sent to the wrong shard."
+                                  << endl;
+                    }
+                }
+                else {
+                    throw;
+                }
+            }
+        }
+    }
+    
+    void ParallelSortClusteredCursor::startInit() {
+
+        bool returnPartial = ( _qSpec.options() & QueryOption_PartialResults );
+        bool specialVersion = _cInfo.versionedNS.size() > 0;
+        bool specialFilter = ! _cInfo.cmdFilter.isEmpty();
+        NamespaceString ns = specialVersion ? _cInfo.versionedNS : _qSpec.ns();
+
+        ChunkManagerPtr manager;
+        ShardPtr primary;
+
+        string prefix;
+        if( _totalTries > 0 ) prefix = str::stream() << "retrying (" << _totalTries << " tries)";
+        else prefix = "creating";
+        log( pc ) << prefix << " pcursor over " << _qSpec << " and " << _cInfo << endl;
+
+        set<Shard> todoStorage;
+        set<Shard>& todo = todoStorage;
+        string vinfo;
+
+        if( isVersioned() ){
+
+            DBConfigPtr config = grid.getDBConfig( ns.db ); // Gets or loads the config
+            uassert( 15989, "database not found for parallel cursor request", config );
+
+            // Try to get either the chunk manager or the primary shard
+            config->getChunkManagerOrPrimary( ns, manager, primary );
+
+            if( manager ) vinfo = ( str::stream() << "[" << manager->getns() << " @ " << manager->getVersion().toString() << "]" );
+            else vinfo = (str::stream() << "[unsharded @ " << primary->toString() << "]" );
+
+            if( manager ) manager->getShardsForQuery( todo, specialFilter ? _cInfo.cmdFilter : _qSpec.filter() );
+            else if( primary ) todo.insert( *primary );
+
+            // Close all cursors on extra shards first, as these will be invalid
+            for( map< Shard, PCMData >::iterator i = _cursorMap.begin(), end = _cursorMap.end(); i != end; ++i ){
+
+                log( pc ) << "closing cursor on shard " << i->first << " as the connection is no longer required by " << vinfo << endl;
+
+                // Force total cleanup of these connections
+                if( todo.find( i->first ) == todo.end() ) i->second.cleanup();
+            }
+        }
+        else{
+
+            // Don't use version to get shards here
+            todo = _qShards;
+            vinfo = str::stream() << "[" << _qShards.size() << " shards specified]";
+
+        }
+
+        verify( todo.size() );
+
+        log( pc ) << "initializing over " << todo.size() << " shards required by " << vinfo << endl;
+
+        // Don't retry indefinitely for whatever reason
+        _totalTries++;
+        uassert( 15986, "too many retries in total", _totalTries < 10 );
+
+        for( set<Shard>::iterator i = todo.begin(), end = todo.end(); i != end; ++i ){
+
+            const Shard& shard = *i;
+            PCMData& mdata = _cursorMap[ shard ];
+
+            log( pc ) << "initializing on shard " << shard << ", current connection state is " << mdata.toBSON() << endl;
+
+            // This may be the first time connecting to this shard, if so we can get an error here
+            try {
+
+                if( mdata.initialized ){
+
+                    verify( mdata.pcState );
+
+                    PCStatePtr state = mdata.pcState;
+
+                    bool compatiblePrimary = true;
+                    bool compatibleManager = true;
+
+                    // Only check for compatibility if we aren't forcing the shard choices
+                    if( isVersioned() ){
+
+                        if( primary && ! state->primary )
+                            warning() << "Collection becoming unsharded detected" << endl;
+                        if( manager && ! state->manager )
+                            warning() << "Collection becoming sharded detected" << endl;
+                        if( primary && state->primary && primary != state->primary )
+                            warning() << "Weird shift of primary detected" << endl;
+
+                        compatiblePrimary = primary && state->primary && primary == state->primary;
+                        compatibleManager = manager && state->manager && manager->compatibleWith( state->manager, shard );
+
+                    }
+
+                    if( compatiblePrimary || compatibleManager ){
+                        // If we're compatible, don't need to retry unless forced
+                        if( ! mdata.retryNext ) continue;
+                        // Do partial cleanup
+                        mdata.cleanup( false );
+                    }
+                    else {
+                        // Force total cleanup of connection if no longer compatible
+                        mdata.cleanup();
+                    }
+                }
+                else {
+                    // Cleanup connection if we're not yet initialized
+                    mdata.cleanup( false );
+                }
+
+                mdata.pcState.reset( new PCState() );
+                PCStatePtr state = mdata.pcState;
+                setupVersionAndHandleSlaveOk( state, shard, primary, ns, vinfo, manager );
+
+                const string& ns = _qSpec.ns();
+
+                // Setup cursor
+                if( ! state->cursor ){
+
+                    // Do a sharded query if this is not a primary shard *and* this is a versioned query,
+                    // or if the number of shards to query is > 1
+                    if( ( isVersioned() && ! primary ) || _qShards.size() > 1 ){
+
+                        state->cursor.reset( new DBClientCursor( state->conn->get(), ns, _qSpec.query(),
+                                                                 isCommand() ? 1 : 0, // nToReturn (0 if query indicates multi)
+                                                                 0, // nToSkip
+                                                                 // Does this need to be a ptr?
+                                                                 _qSpec.fields().isEmpty() ? 0 : _qSpec.fieldsData(), // fieldsToReturn
+                                                                 _qSpec.options(), // options
+                                                                 // NtoReturn is weird.
+                                                                 // If zero, it means use default size, so we do that for all cursors
+                                                                 // If positive, it's the batch size (we don't want this cursor limiting results), that's
+                                                                 // done at a higher level
+                                                                 // If negative, it's the batch size, but we don't create a cursor - so we don't want
+                                                                 // to create a child cursor either.
+                                                                 // Either way, if non-zero, we want to pull back the batch size + the skip amount as
+                                                                 // quickly as possible.  Potentially, for a cursor on a single shard or if we keep better track of
+                                                                 // chunks, we can actually add the skip value into the cursor and/or make some assumptions about the
+                                                                 // return value size ( (batch size + skip amount) / num_servers ).
+                                                                 _qSpec.ntoreturn() == 0 ? 0 :
+                                                                     ( _qSpec.ntoreturn() > 0 ? _qSpec.ntoreturn() + _qSpec.ntoskip() :
+                                                                                                _qSpec.ntoreturn() - _qSpec.ntoskip() ) ) ); // batchSize
+                    }
+                    else{
+
+                        // Non-sharded
+                        state->cursor.reset( new DBClientCursor( state->conn->get(), ns, _qSpec.query(),
+                                                                 _qSpec.ntoreturn(), // nToReturn
+                                                                 _qSpec.ntoskip(), // nToSkip
+                                                                 // Does this need to be a ptr?
+                                                                 _qSpec.fields().isEmpty() ? 0 : _qSpec.fieldsData(), // fieldsToReturn
+                                                                 _qSpec.options(), // options
+                                                                 0 ) ); // batchSize
+                    }
+                }
+
+                bool lazyInit = state->conn->get()->lazySupported();
+                if( lazyInit ){
+
+                    // Need to keep track if this is a second or third try for replica sets
+                    state->cursor->initLazy( mdata.retryNext );
+                    mdata.retryNext = false;
+                    mdata.initialized = true;
+                }
+                else {
+                    bool success = false;
+
+                    if( nsGetCollection( ns ) == "$cmd" ){
+                        /* TODO: remove this when config servers don't use
+                         * SyncClusterConnection anymore. This is needed
+                         * because SyncConn doesn't allow the call() method
+                         * to be used for commands.
+                         */
+                        success = state->cursor->initCommand();
+                    }
+                    else {
+                        success = state->cursor->init();
+                    }
+
+                    // Without full initialization, throw an exception
+                    uassert( 15987, str::stream() << "could not fully initialize cursor on shard "
+                            << shard.toString() << ", current connection state is "
+                            << mdata.toBSON().toString(), success );
+
+                    mdata.retryNext = false;
+                    mdata.initialized = true;
+                    mdata.finished = true;
+                }
+
+
+                log( pc ) << "initialized " << ( isCommand() ? "command " : "query " ) << ( lazyInit ? "(lazily) " : "(full) " ) << "on shard " << shard << ", current connection state is " << mdata.toBSON() << endl;
+
+            }
+            catch( StaleConfigException& e ){
+
+                // Our version isn't compatible with the current version anymore on at least one shard, need to retry immediately
+                NamespaceString staleNS = e.getns();
+
+                // For legacy reasons, this may not be set in the exception :-(
+                if( staleNS.size() == 0 ) staleNS = ns; // ns is the *versioned* namespace, be careful of this
+
+                // Probably need to retry fully
+                bool forceReload, fullReload;
+                _markStaleNS( staleNS, e, forceReload, fullReload );
+
+                int logLevel = fullReload ? 0 : 1;
+                log( pc + logLevel ) << "stale config of ns " << staleNS << " during initialization, will retry with forced : " << forceReload << ", full : " << fullReload << causedBy( e ) << endl;
+
+                // This is somewhat strange
+                if( staleNS != ns )
+                    warning() << "versioned ns " << ns << " doesn't match stale config namespace " << staleNS << endl;
+
+                _handleStaleNS( staleNS, forceReload, fullReload );
+
+                // Restart with new chunk manager
+                startInit();
+                return;
+            }
+            catch( SocketException& e ){
+                warning() << "socket exception when initializing on " << shard << ", current connection state is " << mdata.toBSON() << causedBy( e ) << endl;
+                mdata.errored = true;
+                if( returnPartial ){
+                    mdata.cleanup();
+                    continue;
+                }
+                throw;
+            }
+            catch( DBException& e ){
+                warning() << "db exception when initializing on " << shard << ", current connection state is " << mdata.toBSON() << causedBy( e ) << endl;
+                mdata.errored = true;
+                if( returnPartial && e.getCode() == 15925 /* From above! */ ){
+                    mdata.cleanup();
+                    continue;
+                }
+                throw;
+            }
+            catch( std::exception& e){
+                warning() << "exception when initializing on " << shard << ", current connection state is " << mdata.toBSON() << causedBy( e ) << endl;
+                mdata.errored = true;
+                throw;
+            }
+            catch( ... ){
+                warning() << "unknown exception when initializing on " << shard << ", current connection state is " << mdata.toBSON() << endl;
+                mdata.errored = true;
+                throw;
+            }
+        }
+
+        // Sanity check final init'ed connections
+        for( map< Shard, PCMData >::iterator i = _cursorMap.begin(), end = _cursorMap.end(); i != end; ++i ){
+
+            const Shard& shard = i->first;
+            PCMData& mdata = i->second;
+
+            if( ! mdata.pcState ) continue;
+
+            // Make sure all state is in shards
+            verify( todo.find( shard ) != todo.end() );
+            verify( mdata.initialized == true );
+            if( ! mdata.completed ) verify( mdata.pcState->conn->ok() );
+            verify( mdata.pcState->cursor );
+            if( isVersioned() ) verify( mdata.pcState->primary || mdata.pcState->manager );
+            else verify( ! mdata.pcState->primary || ! mdata.pcState->manager );
+            verify( ! mdata.retryNext );
+
+            if( mdata.completed ) verify( mdata.finished );
+            if( mdata.finished ) verify( mdata.initialized );
+            if( ! returnPartial ) verify( mdata.initialized );
+        }
+
+    }
+
+    void ParallelSortClusteredCursor::finishInit(){
+
+        bool returnPartial = ( _qSpec.options() & QueryOption_PartialResults );
+        bool specialVersion = _cInfo.versionedNS.size() > 0;
+        string ns = specialVersion ? _cInfo.versionedNS : _qSpec.ns();
+
+        bool retry = false;
+        map< string, StaleConfigException > staleNSExceptions;
+
+        log( pc ) << "finishing over " << _cursorMap.size() << " shards" << endl;
+
+        for( map< Shard, PCMData >::iterator i = _cursorMap.begin(), end = _cursorMap.end(); i != end; ++i ){
+
+            const Shard& shard = i->first;
+            PCMData& mdata = i->second;
+
+            log( pc ) << "finishing on shard " << shard << ", current connection state is " << mdata.toBSON() << endl;
+
+            // Ignore empty conns for now
+            if( ! mdata.pcState ) continue;
+
+            PCStatePtr state = mdata.pcState;
+
+            try {
+
+                // Sanity checks
+                if( ! mdata.completed ) verify( state->conn && state->conn->ok() );
+                verify( state->cursor );
+                if( isVersioned() ){
+                    verify( state->manager || state->primary );
+                    verify( ! state->manager || ! state->primary );
+                }
+                else verify( ! state->manager && ! state->primary );
+
+
+                // If we weren't init'ing lazily, ignore this
+                if( ! mdata.finished ){
+
+                    mdata.finished = true;
+
+                    // Mark the cursor as non-retry by default
+                    mdata.retryNext = false;
+
+                    if( ! state->cursor->initLazyFinish( mdata.retryNext ) ){
+                        if( ! mdata.retryNext ){
+                            uassert( 15988, "error querying server", false );
+                        }
+                        else{
+                            retry = true;
+                            continue;
+                        }
+                    }
+
+                    mdata.completed = false;
+                }
+
+                if( ! mdata.completed ){
+
+                    mdata.completed = true;
+
+                    // Make sure we didn't get an error we should rethrow
+                    // TODO : Rename/refactor this to something better
+                    _checkCursor( state->cursor.get() );
+
+                    // Finalize state
+                    state->cursor->attach( state->conn.get() ); // Closes connection for us
+
+                    log( pc ) << "finished on shard " << shard << ", current connection state is " << mdata.toBSON() << endl;
+                }
+            }
+            catch( RecvStaleConfigException& e ){
+                retry = true;
+
+                string staleNS = e.getns();
+                // For legacy reasons, ns may not always be set in exception :-(
+                if( staleNS.size() == 0 ) staleNS = ns; // ns is versioned namespace, be careful of this
+
+                // Will retry all at once
+                staleNSExceptions[ staleNS ] = e;
+
+                // Fully clear this cursor, as it needs to be re-established
+                mdata.cleanup();
+                continue;
+            }
+            catch( SocketException& e ){
+                warning() << "socket exception when finishing on " << shard << ", current connection state is " << mdata.toBSON() << causedBy( e ) << endl;
+                mdata.errored = true;
+                if( returnPartial ){
+                    mdata.cleanup();
+                    continue;
+                }
+                throw;
+            }
+            catch( DBException& e ){
+                warning() << "db exception when finishing on " << shard << ", current connection state is " << mdata.toBSON() << causedBy( e ) << endl;
+                mdata.errored = true;
+                throw;
+            }
+            catch( std::exception& e){
+                warning() << "exception when finishing on " << shard << ", current connection state is " << mdata.toBSON() << causedBy( e ) << endl;
+                mdata.errored = true;
+                throw;
+            }
+            catch( ... ){
+                warning() << "unknown exception when finishing on " << shard << ", current connection state is " << mdata.toBSON() << endl;
+                mdata.errored = true;
+                throw;
+            }
+
+        }
+
+        // Retry logic for single refresh of namespaces / retry init'ing connections
+        if( retry ){
+
+            // Refresh stale namespaces
+            if( staleNSExceptions.size() ){
+                for( map<string,StaleConfigException>::iterator i = staleNSExceptions.begin(), end = staleNSExceptions.end(); i != end; ++i ){
+
+                    const string& staleNS = i->first;
+                    const StaleConfigException& exception = i->second;
+
+                    bool forceReload, fullReload;
+                    _markStaleNS( staleNS, exception, forceReload, fullReload );
+
+                    int logLevel = fullReload ? 0 : 1;
+                    log( pc + logLevel ) << "stale config of ns " << staleNS << " on finishing query, will retry with forced : " << forceReload << ", full : " << fullReload << causedBy( exception ) << endl;
+
+                    // This is somewhat strange
+                    if( staleNS != ns )
+                        warning() << "versioned ns " << ns << " doesn't match stale config namespace " << staleNS << endl;
+
+                    _handleStaleNS( staleNS, forceReload, fullReload );
+                }
+            }
+
+            // Re-establish connections we need to
+            startInit();
+            finishInit();
+            return;
+        }
+
+        // Sanity check and clean final connections
+        map< Shard, PCMData >::iterator i = _cursorMap.begin();
+        while( i != _cursorMap.end() ){
+
+            // const Shard& shard = i->first;
+            PCMData& mdata = i->second;
+
+            // Erase empty stuff
+            if( ! mdata.pcState ){
+                log() << "PCursor erasing empty state " << mdata.toBSON() << endl;
+                _cursorMap.erase( i++ );
+                continue;
+            }
+            else ++i;
+
+            // Make sure all state is in shards
+            verify( mdata.initialized == true );
+            verify( mdata.finished == true );
+            verify( mdata.completed == true );
+            verify( ! mdata.pcState->conn->ok() );
+            verify( mdata.pcState->cursor );
+            if( isVersioned() ) verify( mdata.pcState->primary || mdata.pcState->manager );
+            else verify( ! mdata.pcState->primary && ! mdata.pcState->manager );
+        }
+
+        // TODO : More cleanup of metadata?
+
+        // LEGACY STUFF NOW
+
+        _cursors = new FilteringClientCursor[ _cursorMap.size() ];
+
+        // Put the cursors in the legacy format
+        int index = 0;
+        for( map< Shard, PCMData >::iterator i = _cursorMap.begin(), end = _cursorMap.end(); i != end; ++i ){
+
+            PCMData& mdata = i->second;
+
+            _cursors[ index ].reset( mdata.pcState->cursor.get(), &mdata );
+            _servers.insert( ServerAndQuery( i->first.getConnString(), BSONObj() ) );
+
+            index++;
+        }
+
+        _numServers = _cursorMap.size();
+
+    }
+
+    bool ParallelSortClusteredCursor::isSharded() {
+        // LEGACY is always unsharded
+        if( _qSpec.isEmpty() ) return false;
+
+        if( ! isVersioned() ) return false;
+
+        if( _cursorMap.size() > 1 ) return true;
+        if( _cursorMap.begin()->second.pcState->manager ) return true;
+        return false;
+    }
+
+    ShardPtr ParallelSortClusteredCursor::getPrimary() {
+        if( isSharded() || ! isVersioned() ) return ShardPtr();
+        return _cursorMap.begin()->second.pcState->primary;
+    }
+
+    void ParallelSortClusteredCursor::getQueryShards( set<Shard>& shards ) {
+        for( map< Shard, PCMData >::iterator i = _cursorMap.begin(), end = _cursorMap.end(); i != end; ++i ){
+            shards.insert( i->first );
+        }
+    }
+
+    ChunkManagerPtr ParallelSortClusteredCursor::getChunkManager( const Shard& shard ) {
+        if( ! isSharded() ) return ChunkManagerPtr();
+
+        map<Shard,PCMData>::iterator i = _cursorMap.find( shard );
+
+        if( i == _cursorMap.end() ) return ChunkManagerPtr();
+        else return i->second.pcState->manager;
+    }
+
+    DBClientCursorPtr ParallelSortClusteredCursor::getShardCursor( const Shard& shard ) {
+        map<Shard,PCMData>::iterator i = _cursorMap.find( shard );
+
+        if( i == _cursorMap.end() ) return DBClientCursorPtr();
+        else return i->second.pcState->cursor;
+    }
+
+    void ParallelSortClusteredCursor::_init() {
+        if( ! _qSpec.isEmpty() ) fullInit();
+        else _oldInit();
+    }
+
+
+    // DEPRECATED
+
+
+    // TODO:  Merge with futures API?  We do a lot of error checking here that would be useful elsewhere.
+    void ParallelSortClusteredCursor::_oldInit() {
+
+        // log() << "Starting parallel search..." << endl;
+
+        // make sure we're not already initialized
+        verify( ! _cursors );
+        _cursors = new FilteringClientCursor[_numServers];
+
+        bool returnPartial = ( _options & QueryOption_PartialResults );
+
+        vector<ServerAndQuery> queries( _servers.begin(), _servers.end() );
+        set<int> retryQueries;
+        int finishedQueries = 0;
+
+        vector< shared_ptr<ShardConnection> > conns;
+        vector<string> servers;
+
+        // Since we may get all sorts of errors, record them all as they come and throw them later if necessary
+        vector<string> staleConfigExs;
+        vector<string> socketExs;
+        vector<string> otherExs;
+        bool allConfigStale = false;
+
+        int retries = -1;
+
+        // Loop through all the queries until we've finished or gotten a socket exception on all of them
+        // We break early for non-socket exceptions, and socket exceptions if we aren't returning partial results
+        do {
+            retries++;
+
+            bool firstPass = retryQueries.size() == 0;
+
+            if( ! firstPass ){
+                log() << "retrying " << ( returnPartial ? "(partial) " : "" ) << "parallel connection to ";
+                for( set<int>::iterator it = retryQueries.begin(); it != retryQueries.end(); ++it ){
+                    log() << queries[*it]._server << ", ";
+                }
+                log() << finishedQueries << " finished queries." << endl;
+            }
+
+            size_t num = 0;
+            for ( vector<ServerAndQuery>::iterator it = queries.begin(); it != queries.end(); ++it ) {
+                size_t i = num++;
+
+                const ServerAndQuery& sq = *it;
+
+                // If we're not retrying this cursor on later passes, continue
+                if( ! firstPass && retryQueries.find( i ) == retryQueries.end() ) continue;
+
+                // log() << "Querying " << _query << " from " << _ns << " for " << sq._server << endl;
+
+                BSONObj q = _query;
+                if ( ! sq._extra.isEmpty() ) {
+                    q = concatQuery( q , sq._extra );
+                }
+
+                string errLoc = " @ " + sq._server;
+
+                if( firstPass ){
+
+                    // This may be the first time connecting to this shard, if so we can get an error here
+                    try {
+                        conns.push_back( shared_ptr<ShardConnection>( new ShardConnection( sq._server , _ns ) ) );
+                    }
+                    catch( std::exception& e ){
+                        socketExs.push_back( e.what() + errLoc );
+                        if( ! returnPartial ){
+                            num--;
+                            break;
+                        }
+                        conns.push_back( shared_ptr<ShardConnection>() );
+                        continue;
+                    }
+
+                    servers.push_back( sq._server );
+                }
+
+                if ( conns[i]->setVersion() ) {
+                    conns[i]->done();
+                    // Version is zero b/c this is deprecated codepath
+                    staleConfigExs.push_back( (string)"stale config detected for " + RecvStaleConfigException( _ns , "ParallelCursor::_init" , ShardChunkVersion( 0, OID() ), ShardChunkVersion( 0, OID() ), true ).what() + errLoc );
+                    break;
+                }
+
+                LOG(5) << "ParallelSortClusteredCursor::init server:" << sq._server << " ns:" << _ns
+                       << " query:" << q << " _fields:" << _fields << " options: " << _options  << endl;
+
+                if( ! _cursors[i].raw() )
+                    _cursors[i].reset( new DBClientCursor( conns[i]->get() , _ns , q ,
+                                                            0 , // nToReturn
+                                                            0 , // nToSkip
+                                                            _fields.isEmpty() ? 0 : &_fields , // fieldsToReturn
+                                                            _options ,
+                                                            _batchSize == 0 ? 0 : _batchSize + _needToSkip // batchSize
+                                                            ) );
+
+                try{
+                    _cursors[i].raw()->initLazy( ! firstPass );
+                }
+                catch( SocketException& e ){
+                    socketExs.push_back( e.what() + errLoc );
+                    _cursors[i].reset( NULL );
+                    conns[i]->done();
+                    if( ! returnPartial ) break;
+                }
+                catch( std::exception& e){
+                    otherExs.push_back( e.what() + errLoc );
+                    _cursors[i].reset( NULL );
+                    conns[i]->done();
+                    break;
+                }
+
+            }
+
+            // Go through all the potentially started cursors and finish initializing them or log any errors and
+            // potentially retry
+            // TODO:  Better error classification would make this easier, errors are indicated in all sorts of ways
+            // here that we need to trap.
+            for ( size_t i = 0; i < num; i++ ) {
+
+                // log() << "Finishing query for " << cons[i].get()->getHost() << endl;
+                string errLoc = " @ " + queries[i]._server;
+
+                if( ! _cursors[i].raw() || ( ! firstPass && retryQueries.find( i ) == retryQueries.end() ) ){
+                    if( conns[i] ) conns[i].get()->done();
+                    continue;
+                }
+
+                verify( conns[i] );
+                retryQueries.erase( i );
+
+                bool retry = false;
+
+                try {
+
+                    if( ! _cursors[i].raw()->initLazyFinish( retry ) ) {
+
+                        warning() << "invalid result from " << conns[i]->getHost() << ( retry ? ", retrying" : "" ) << endl;
+                        _cursors[i].reset( NULL );
+
+                        if( ! retry ){
+                            socketExs.push_back( str::stream() << "error querying server: " << servers[i] );
+                            conns[i]->done();
+                        }
+                        else {
+                            retryQueries.insert( i );
+                        }
+
+                        continue;
+                    }
+                }
+                catch ( StaleConfigException& e ){
+                    // Our stored configuration data is actually stale, we need to reload it
+                    // when we throw our exception
+                    allConfigStale = true;
+
+                    staleConfigExs.push_back( (string)"stale config detected when receiving response for " + e.what() + errLoc );
+                    _cursors[i].reset( NULL );
+                    conns[i]->done();
+                    continue;
+                }
+                catch ( SocketException& e ) {
+                    socketExs.push_back( e.what() + errLoc );
+                    _cursors[i].reset( NULL );
+                    conns[i]->done();
+                    continue;
+                }
+                catch( std::exception& e ){
+                    otherExs.push_back( e.what() + errLoc );
+                    _cursors[i].reset( NULL );
+                    conns[i]->done();
+                    continue;
+                }
+
+                try {
+                    _cursors[i].raw()->attach( conns[i].get() ); // this calls done on conn
+                    _checkCursor( _cursors[i].raw() );
+
+                    finishedQueries++;
+                }
+                catch ( StaleConfigException& e ){
+
+                    // Our stored configuration data is actually stale, we need to reload it
+                    // when we throw our exception
+                    allConfigStale = true;
+
+                    staleConfigExs.push_back( (string)"stale config detected for " + e.what() + errLoc );
+                    _cursors[i].reset( NULL );
+                    conns[i]->done();
+                    continue;
+                }
+                catch( std::exception& e ){
+                    otherExs.push_back( e.what() + errLoc );
+                    _cursors[i].reset( NULL );
+                    conns[i]->done();
+                    continue;
+                }
+            }
+
+            // Don't exceed our max retries, should not happen
+            verify( retries < 5 );
+        }
+        while( retryQueries.size() > 0 /* something to retry */ &&
+               ( socketExs.size() == 0 || returnPartial ) /* no conn issues */ &&
+               staleConfigExs.size() == 0 /* no config issues */ &&
+               otherExs.size() == 0 /* no other issues */);
+
+        // Assert that our conns are all closed!
+        for( vector< shared_ptr<ShardConnection> >::iterator i = conns.begin(); i < conns.end(); ++i ){
+            verify( ! (*i) || ! (*i)->ok() );
+        }
+
+        // Handle errors we got during initialization.
+        // If we're returning partial results, we can ignore socketExs, but nothing else
+        // Log a warning in any case, so we don't lose these messages
+        bool throwException = ( socketExs.size() > 0 && ! returnPartial ) || staleConfigExs.size() > 0 || otherExs.size() > 0;
+
+        if( socketExs.size() > 0 || staleConfigExs.size() > 0 || otherExs.size() > 0 ) {
+
+            vector<string> errMsgs;
+
+            errMsgs.insert( errMsgs.end(), staleConfigExs.begin(), staleConfigExs.end() );
+            errMsgs.insert( errMsgs.end(), otherExs.begin(), otherExs.end() );
+            errMsgs.insert( errMsgs.end(), socketExs.begin(), socketExs.end() );
+
+            stringstream errMsg;
+            errMsg << "could not initialize cursor across all shards because : ";
+            for( vector<string>::iterator i = errMsgs.begin(); i != errMsgs.end(); i++ ){
+                if( i != errMsgs.begin() ) errMsg << " :: and :: ";
+                errMsg << *i;
+            }
+
+            if( throwException && staleConfigExs.size() > 0 ){
+                // Version is zero b/c this is deprecated codepath
+                throw RecvStaleConfigException( _ns , errMsg.str() , ShardChunkVersion( 0, OID() ), ShardChunkVersion( 0, OID() ), ! allConfigStale );
+            }
+            else if( throwException )
+                throw DBException( errMsg.str(), 14827 );
+            else
+                warning() << errMsg.str() << endl;
+        }
+
+        if( retries > 0 )
+            log() <<  "successfully finished parallel query after " << retries << " retries" << endl;
+
+    }
+
+    ParallelSortClusteredCursor::~ParallelSortClusteredCursor() {
+        // Clear out our metadata before removing legacy cursor data
+        _cursorMap.clear();
+        for( int i = 0; i < _numServers; i++ ) _cursors[i].release();
+
+        delete [] _cursors;
+        _cursors = 0;
+    }
+
+    bool ParallelSortClusteredCursor::more() {
+
+        if ( _needToSkip > 0 ) {
+            int n = _needToSkip;
+            _needToSkip = 0;
+
+            while ( n > 0 && more() ) {
+                BSONObj x = next();
+                n--;
+            }
+
+            _needToSkip = n;
+        }
+
+        for ( int i=0; i<_numServers; i++ ) {
+            if ( _cursors[i].more() )
+                return true;
+        }
+        return false;
+    }
+
+    BSONObj ParallelSortClusteredCursor::next() {
+        BSONObj best = BSONObj();
+        int bestFrom = -1;
+
+        for( int j = 0; j < _numServers; j++ ){
+
+            // Iterate _numServers times, starting one past the last server we used.
+            // This means we actually start at server #1, not #0, but shouldn't matter
+
+            int i = ( j + _lastFrom + 1 ) % _numServers;
+
+            if ( ! _cursors[i].more() ){
+                if( _cursors[i].rawMData() )
+                    _cursors[i].rawMData()->pcState->done = true;
+                continue;
+            }
+
+            BSONObj me = _cursors[i].peek();
+
+            if ( best.isEmpty() ) {
+                best = me;
+                bestFrom = i;
+                if( _sortKey.isEmpty() ) break;
+                continue;
+            }
+
+            int comp = best.woSortOrder( me , _sortKey , true );
+            if ( comp < 0 )
+                continue;
+
+            best = me;
+            bestFrom = i;
+        }
+
+        _lastFrom = bestFrom;
+
+        uassert( 10019 ,  "no more elements" , ! best.isEmpty() );
+        _cursors[bestFrom].next();
+
+        if( _cursors[bestFrom].rawMData() )
+            _cursors[bestFrom].rawMData()->pcState->count++;
+
+        return best;
+    }
+
+    void ParallelSortClusteredCursor::_explain( map< string,list<BSONObj> >& out ) {
+
+        set<Shard> shards;
+        getQueryShards( shards );
+
+        for( set<Shard>::iterator i = shards.begin(), end = shards.end(); i != end; ++i ){
+            // TODO: Make this the shard name, not address
+            list<BSONObj>& l = out[ i->getAddress().toString() ];
+            l.push_back( getShardCursor( *i )->peekFirst().getOwned() );
+        }
+
+    }
+
+    // -----------------
+    // ---- Future -----
+    // -----------------
+
+    Future::CommandResult::CommandResult( const string& server , const string& db , const BSONObj& cmd , int options , DBClientBase * conn )
+        :_server(server) ,_db(db) , _options(options), _cmd(cmd) ,_conn(conn) ,_done(false)
+    {
+        init();
+    }
+
+    void Future::CommandResult::init(){
+        try {
+            if ( ! _conn ){
+                _connHolder.reset( ScopedDbConnection::getScopedDbConnection( _server ) );
+                _conn = _connHolder->get();
+            }
+
+            if ( _conn->lazySupported() ) {
+                BSONObj actualCommand = _cmd;
+                if ( !noauth ) {
+                    actualCommand = ClientBasic::getCurrent()->getAuthenticationInfo()->
+                        getAuthTable().copyCommandObjAddingAuth( _cmd );
+                }
+                _cursor.reset( new DBClientCursor(_conn, _db + ".$cmd", actualCommand,
+                                                  -1/*limit*/, 0, NULL, _options, 0));
+                _cursor->initLazy();
+            }
+            else {
+                _done = true; // we set _done first because even if there is an error we're done
+                _ok = _conn->runCommand( _db , _cmd , _res , _options );
+            }
+        }
+        catch ( std::exception& e ) {
+            error() << "Future::spawnComand (part 1) exception: " << e.what() << endl;
+            _ok = false;
+            _done = true;
+        }
+    }
+
+    bool Future::CommandResult::join( int maxRetries ) {
+        if (_done)
+            return _ok;
+
+
+        _ok = false;
+        for( int i = 1; i <= maxRetries; i++ ){
+
+            try {
+                bool retry = false;
+                bool finished = _cursor->initLazyFinish( retry );
+
+                // Shouldn't need to communicate with server any more
+                if ( _connHolder )
+                    _connHolder->done();
+
+                uassert(14812,  str::stream() << "Error running command on server: " << _server, finished);
+                massert(14813, "Command returned nothing", _cursor->more());
+
+                _res = _cursor->nextSafe();
+                _ok = _res["ok"].trueValue();
+
+                break;
+            }
+            catch ( RecvStaleConfigException& e ){
+
+                verify( versionManager.isVersionableCB( _conn ) );
+
+                // For legacy reasons, we may not always have a namespace :-(
+                string staleNS = e.getns();
+                if( staleNS.size() == 0 ) staleNS = _db;
+
+                if( i >= maxRetries ){
+                    error() << "Future::spawnComand (part 2) stale config exception" << causedBy( e ) << endl;
+                    throw e;
+                }
+
+                if( i >= maxRetries / 2 ){
+                    if( ! versionManager.forceRemoteCheckShardVersionCB( staleNS ) ){
+                        error() << "Future::spawnComand (part 2) no config detected" << causedBy( e ) << endl;
+                        throw e;
+                    }
+                }
+
+                // We may not always have a collection, since we don't know from a generic command what collection
+                // is supposed to be acted on, if any
+                if( nsGetCollection( staleNS ).size() == 0 ){
+                    warning() << "no collection namespace in stale config exception "
+                              << "for lazy command " << _cmd << ", could not refresh "
+                              << staleNS << endl;
+                }
+                else {
+                    versionManager.checkShardVersionCB( _conn, staleNS, false, 1 );
+                }
+
+                LOG( i > 1 ? 0 : 1 ) << "retrying lazy command" << causedBy( e ) << endl;
+
+                verify( _conn->lazySupported() );
+                _done = false;
+                init();
+                continue;
+            }
+            catch ( std::exception& e ) {
+                error() << "Future::spawnComand (part 2) exception: " << causedBy( e ) << endl;
+                break;
+            }
+
+        }
+
+        _done = true;
+        return _ok;
+    }
+
+    shared_ptr<Future::CommandResult> Future::spawnCommand( const string& server , const string& db , const BSONObj& cmd , int options , DBClientBase * conn ) {
+        shared_ptr<Future::CommandResult> res (new Future::CommandResult( server , db , cmd , options , conn  ));
+        return res;
+    }
+
+}