diff --git a/db/client.cpp b/db/client.cpp
index 8341dedbb68..b19daaa5bcc 100644
--- a/db/client.cpp
+++ b/db/client.cpp
@@ -34,11 +34,13 @@ namespace mongo {
 
     Client::Client(const char *desc) : 
       _curOp(new CurOp()),
-      _database(0), _ns("")/*, _nsstr("")*/ 
-      ,_shutdown(false),
+      _context(0),
+      //_database(0), _ns("")/*, _nsstr("")*/ 
+      _shutdown(false),
       _desc(desc),
-      _god(0)
-    { 
+      _god(0),
+      _prevDB( 0 )
+    {
         ai = new AuthenticationInfo(); 
         boostlock bl(clientsMutex);
         clients.insert(this);
@@ -49,9 +51,11 @@ namespace mongo {
         delete ai; 
         ai = 0;
         _god = 0;
-        if ( !_shutdown ) {
+
+        if ( _context )
+            cout << "ERROR: Client::~Client _context should be NULL" << endl;
+        if ( !_shutdown ) 
             cout << "ERROR: Client::shutdown not called!" << endl;
-        }
     }
 
     bool Client::shutdown(){
@@ -69,7 +73,7 @@ namespace mongo {
             for ( list<string>::iterator i = _tempCollections.begin(); i!=_tempCollections.end(); i++ ){
                 string ns = *i;
                 dblock l;
-                setClient( ns.c_str() );
+                Client::Context ctx( ns );
                 if ( ! nsdetails( ns.c_str() ) )
                     continue;
                 try {
@@ -91,9 +95,31 @@ namespace mongo {
     AtomicUInt CurOp::_nextOpNum;
     
     Client::Context::Context( string ns , Database * db )
-        : _client( currentClient.get() ) {
+        : _client( currentClient.get() ) , _oldContext( _client->_context ) , 
+          _path( dbpath ) , _lock(0) , _justCreated(false) {
         assert( db && db->isOk() );
-        _client->setns( ns.c_str() , db );
+        _ns = ns;
+        _db = db;
+        _client->_context = this;
+    }
+
+    void Client::Context::_finishInit(){
+        dbMutex.assertAtLeastReadLocked();
+        
+        _db = dbHolder.get( _ns , _path );
+        if ( _db ){
+            _justCreated = false;
+        }
+        else {
+            // we need to be in a write lock since we're going to create the DB object
+            if ( _lock )
+                _lock->releaseAndWriteLock();
+            assertInWriteLock();
+            
+            _db = dbHolder.getOrCreate( _ns , _path , _justCreated );
+        }
+        
+        _client->_context = this;
     }
 
 }
diff --git a/db/client.h b/db/client.h
index 99092caca45..43d4d1ef674 100644
--- a/db/client.h
+++ b/db/client.h
@@ -39,9 +39,6 @@ namespace mongo {
 
     extern boost::thread_specific_ptr<Client> currentClient;
 
-    bool setClient(const char *ns, const string& path=dbpath, mongolock *lock = 0);
-
-
     class Client : boost::noncopyable { 
     public:
         static boost::mutex clientsMutex;
@@ -57,30 +54,40 @@ namespace mongo {
         /* Set database we want to use, then, restores when we finish (are out of scope)
            Note this is also helpful if an exception happens as the state if fixed up.
         */
-        class Context {
+        class Context : boost::noncopyable{
             Client * _client;
-            Database * _olddb;
-            string _oldns;
+            Context * _oldContext;
+            
+            string _path;
+            mongolock * _lock;
+            bool _justCreated;
+
+            string _ns;
+            Database * _db;
+
+            /**
+             * at this point _client, _oldContext and _ns have to be set
+             * _db should not have been touched
+             * this will set _db and create if needed
+             * will also set _client->_context to this
+             */
+            void _finishInit();
+
+            
         public:
-            Context(const char *ns) 
-                : _client( currentClient.get() ) {
-                _olddb = _client->_database;
-                _oldns = _client->_ns;
-                setClient(ns);
-            }
-            Context(string ns) 
-                : _client( currentClient.get() ){
-                _olddb = _client->_database;
-                _oldns = _client->_ns;
-                setClient(ns.c_str());
+            Context(const string& ns, string path=dbpath, mongolock * lock = 0 ) 
+                : _client( currentClient.get() ) , _oldContext( _client->_context ) , 
+                  _path( path ) , _lock( lock ) ,
+                  _ns( ns ){
+                _finishInit();
             }
             
             /* this version saves the context but doesn't yet set the new one: */
             Context() 
-                : _client( currentClient.get() ) {
-                _olddb = _client->database();
-                _oldns = _client->ns();        
-
+                : _client( currentClient.get() ) , _oldContext( _client->_context ), 
+                  _path( dbpath ) , _lock(0) , _justCreated(false){
+                _client->_context = this;
+                clear();
             }
             
             /**
@@ -91,37 +98,80 @@ namespace mongo {
 
             ~Context() {
                 DEV assert( _client == currentClient.get() );
-                _client->setns( _oldns.c_str(), _olddb );
+                _client->_context = _oldContext; // note: _oldContext may be null
+                _client->_prevDB = _db;
+            }
+            
+            Database* db() const {
+                return _db;
             }
 
-        };
+            const char * ns() const {
+                return _ns.c_str();
+            }
+            
+            bool justCreated() const {
+                return _justCreated;
+            }
 
+            bool equals( const string& ns , const string& path=dbpath ) const {
+                return _ns == ns && _path == path;
+            }
+
+            bool inDB( const string& db , const string& path=dbpath ) const {
+                if ( _path != path )
+                    return false;
+                
+                if ( db == _ns )
+                    return true;
+
+                string::size_type idx = _ns.find( db );
+                if ( idx != 0 )
+                    return false;
+                
+                return  _ns[db.size()] == '.';
+            }
+
+            void clear(){
+                _ns = "";
+                _db = 0;
+            }
+
+            /**
+             * call before unlocking, so clear any non-thread safe state
+             */
+            void unlocked(){
+                _db = 0;
+            }
+
+            /**
+             * call after going back into the lock, will re-establish non-thread safe stuff
+             */
+            void relocked(){
+                _finishInit();
+            }
+        };
+        
     private:
         CurOp * const _curOp;
-        Database *_database;
-        Namespace _ns;
-        //NamespaceString _nsstr;
+        Context * _context;
         bool _shutdown;
         list<string> _tempCollections;
         const char *_desc;
         bool _god;
+
+        Database * _prevDB;
     public:
         AuthenticationInfo *ai;
         Top top;
 
         CurOp* curop() { return _curOp; }
-        Database* database() { 
-            return _database; 
-        }
-        const char *ns() { return _ns.buf; }
-
-        void setns(const char *ns, Database *db) { 
-            _database = db;
-            _ns = ns;
-            //_nsstr = ns;
-        }
-        void clearns() { setns("", 0); }
-
+        
+        Context* getContext(){ return _context; }
+        Database* database() {  return _context ? _context->db() : 0; }
+        const char *ns() { return _context->ns(); }
+        Database* prevDatabase(){ return _prevDB; }
+        
         Client(const char *desc);
         ~Client();
 
@@ -185,7 +235,8 @@ namespace mongo {
             /* this is defensive; as we were unlocked for a moment above, 
                the Database object we reference could have been deleted:
             */
-            cc().clearns();
+            assert( ! cc().getContext() );
+            //cc().clearns();
         }
     }
     
diff --git a/db/cloner.cpp b/db/cloner.cpp
index 33b14142bea..bf819bbf7ac 100644
--- a/db/cloner.cpp
+++ b/db/cloner.cpp
@@ -462,7 +462,7 @@ namespace mongo {
             /* replication note: we must logOp() not the command, but the cloned data -- if the slave
              were to clone it would get a different point-in-time and not match.
              */
-            setClient( collection.c_str() );
+            Client::Context ctx( collection );
             
             log() << "cloneCollection.  db:" << ns << " collection:" << collection << " from: " << fromhost << " query: " << query << " logSizeMb: " << logSizeMb << ( copyIndexes ? "" : ", not copying indexes" ) << endl;
             
@@ -506,7 +506,7 @@ namespace mongo {
             /* replication note: we must logOp() not the command, but the cloned data -- if the slave
              were to clone it would get a different point-in-time and not match.
              */
-            setClient( collection.c_str() );
+            Client::Context ctx(collection);
             
             log() << "startCloneCollection.  db:" << ns << " collection:" << collection << " from: " << fromhost << " query: " << query << endl;
             
@@ -562,7 +562,7 @@ namespace mongo {
                 cursorId = cursorIdToken._numberLong();
             }
             
-            setClient( collection.c_str() );
+            Client::Context ctx( collection );
             
             log() << "finishCloneCollection.  db:" << ns << " collection:" << collection << " from: " << fromhost << " query: " << query << endl;
             
@@ -601,9 +601,8 @@ namespace mongo {
                 errmsg = "parms missing - {copydb: 1, fromhost: <hostname>, fromdb: <db>, todb: <db>}";
                 return false;
             }
-            setClient(todb.c_str());
+            Client::Context ctx(todb);
             bool res = cloneFrom(fromhost.c_str(), errmsg, fromdb, /*logForReplication=*/!fromRepl, /*slaveok*/false, /*replauth*/false, /*snapshot*/true);
-            cc().clearns();
             return res;
         }
     } cmdcopydb;
@@ -631,16 +630,19 @@ namespace mongo {
                 return false;
             }
             
-            setClient( source.c_str() );
-            NamespaceDetails *nsd = nsdetails( source.c_str() );
-            uassert( 10026 ,  "source namespace does not exist", nsd );
-            bool capped = nsd->capped;
+            bool capped = false;
             long long size = 0;
-            if ( capped )
-                for( DiskLoc i = nsd->firstExtent; !i.isNull(); i = i.ext()->xnext )
-                    size += i.ext()->length;
+            {
+                Client::Context ctx( source );
+                NamespaceDetails *nsd = nsdetails( source.c_str() );
+                uassert( 10026 ,  "source namespace does not exist", nsd );
+                capped = nsd->capped;
+                if ( capped )
+                    for( DiskLoc i = nsd->firstExtent; !i.isNull(); i = i.ext()->xnext )
+                        size += i.ext()->length;
+            }
             
-            setClient( target.c_str() );
+            Client::Context ctx( target );
             
             if ( nsdetails( target.c_str() ) ){
                 uassert( 10027 ,  "target namespace exists", cmdObj["dropTarget"].trueValue() );
@@ -715,8 +717,10 @@ namespace mongo {
                 theDataFileMgr.insert( targetIndexes.c_str(), n );
             }
 
-            setClient( source.c_str() );
-            dropCollection( source, errmsg, result );
+            {
+                Client::Context ctx( source );
+                dropCollection( source, errmsg, result );
+            }
             return true;
         }
     } cmdrenamecollection;
diff --git a/db/db.cpp b/db/db.cpp
index a472f074a3e..1e63bc90e53 100644
--- a/db/db.cpp
+++ b/db/db.cpp
@@ -69,7 +69,10 @@ namespace mongo {
 
     const char *ourgetns() { 
         Client *c = currentClient.get();
-        return c ? c->ns() : "";
+        if ( ! c )
+            return "";
+        Client::Context* cc = c->getContext();
+        return cc ? cc->ns() : "";
     }
 
     struct MyStartupTests {
@@ -82,7 +85,7 @@ namespace mongo {
 
     void testTheDb() {
         OpDebug debug;
-        setClient("sys.unittest.pdfile");
+        Client::Context ctx("sys.unittest.pdfile");
 
         /* this is not validly formatted, if you query this namespace bad things will happen */
         theDataFileMgr.insert("sys.unittest.pdfile", (void *) "hello worldx", 13);
@@ -101,8 +104,6 @@ namespace mongo {
             c->advance();
         }
         out() << endl;
-
-        cc().clearns();
     }
 
     MessagingPort *connGrab = 0;
@@ -346,7 +347,7 @@ namespace mongo {
         for ( vector< string >::iterator i = dbNames.begin(); i != dbNames.end(); ++i ) {
             string dbName = *i;
             log(1) << "\t" << dbName << endl;
-            assert( !setClient( dbName.c_str() ) );
+            Client::Context ctx( dbName );
             MongoDataFile *p = cc().database()->getFile( 0 );
             MDFHeader *h = p->getHeader();
             if ( !h->currentVersion() || forceRepair ) {
@@ -394,8 +395,9 @@ namespace mongo {
                 boost::filesystem::remove_all( *i );
         }
     }
-
+    
     void clearTmpCollections() {
+        Client::GodScope gs;
         vector< string > toDelete;
         DBDirectClient cli;
         auto_ptr< DBClientCursor > c = cli.query( "local.system.namespaces", Query( fromjson( "{name:/^local.temp./}" ) ) );
@@ -408,7 +410,7 @@ namespace mongo {
             cli.dropCollection( *i );
         }
     }
-
+    
     /**
      * does background async flushes of mmapped files
      */
diff --git a/db/db.h b/db/db.h
index e55e8091d34..d0e9642ef3b 100644
--- a/db/db.h
+++ b/db/db.h
@@ -49,7 +49,7 @@ namespace mongo {
     public:
         DatabaseHolder() : _size(0){
         }
-
+        
         Database * get( const string& ns , const string& path ){
             dbMutex.assertAtLeastReadLocked();
             map<string,Database*>& m = _paths[path];
@@ -71,6 +71,26 @@ namespace mongo {
             d = db;
         }
         
+        Database* getOrCreate( const string& ns , const string& path , bool& justCreated ){
+            dbMutex.assertWriteLocked();
+            map<string,Database*>& m = _paths[path];
+            
+            string dbname = _todb( ns );
+
+            Database* & db = m[dbname];
+            if ( db ){
+                justCreated = false;
+                return db;
+            }
+            
+            log(1) << "Accessing: " << dbname << " for the first time" << endl;
+            db = new Database( dbname.c_str() , justCreated , path );
+            return db;
+        }
+        
+
+
+
         void erase( const string& ns , const string& path ){
             dbMutex.assertWriteLocked();
             map<string,Database*>& m = _paths[path];
@@ -113,81 +133,42 @@ namespace mongo {
 
     extern DatabaseHolder dbHolder;
 
-    /* returns true if the database ("database") did not exist, and it was created on this call 
-       path - datafiles directory, if not the default, so we can differentiate between db's of the same
-              name in different places (for example temp ones on repair).
-    */
-    inline bool setClient(const char *ns, const string& path , mongolock *lock ) {
-        if( logLevel > 5 )
-            log() << "setClient: " << ns << endl;
-
-        dbMutex.assertAtLeastReadLocked();
-
-        Client& c = cc();
-        c.top.clientStart( ns );
-
-        Database * db = dbHolder.get( ns , path );
-        if ( db ){
-            c.setns(ns, db );
-            return false;
-        }
-
-        if( lock )
-            lock->releaseAndWriteLock();
-
-        assertInWriteLock();
-        
-        char cl[256];
-        nsToDatabase(ns, cl);
-        bool justCreated;
-        Database *newdb = new Database(cl, justCreated, path);
-        dbHolder.put(ns,path,newdb);
-        c.setns(ns, newdb);
-
-        newdb->finishInit();
-
-        return justCreated;
-    }
-
     // shared functionality for removing references to a database from this program instance
     // does not delete the files on disk
     void closeDatabase( const char *cl, const string& path = dbpath );
-
+    
     struct dbtemprelease {
-        string clientname;
-        string clientpath;
-        int locktype;
+        Client::Context * _context;
+        int _locktype;
+        
         dbtemprelease() {
-            Client& client = cc();
-            Database *database = client.database();
-            if ( database ) {
-                clientname = database->name;
-                clientpath = database->path;
-            }
-            client.top.clientStop();
-            locktype = dbMutex.getState();
-            assert( locktype );
-            if ( locktype > 0 ) {
-				massert( 10298 , "can't temprelease nested write lock", locktype == 1);
+            _context = cc().getContext();
+            _locktype = dbMutex.getState();
+            assert( _locktype );
+            
+            if ( _locktype > 0 ) {
+				massert( 10298 , "can't temprelease nested write lock", _locktype == 1);
+                if ( _context ) _context->unlocked();
                 dbMutex.unlock();
 			}
             else {
-				massert( 10299 , "can't temprelease nested read lock", locktype == -1);
+				massert( 10299 , "can't temprelease nested read lock", _locktype == -1);
+                if ( _context ) _context->unlocked();
                 dbMutex.unlock_shared();
 			}
+
         }
         ~dbtemprelease() {
-            if ( locktype > 0 )
+            if ( _locktype > 0 )
                 dbMutex.lock();
             else
                 dbMutex.lock_shared();
-            if ( clientname.empty() )
-                cc().setns("", 0);
-            else
-                setClient(clientname.c_str(), clientpath.c_str());
+            
+            if ( _context ) _context->relocked();
         }
     };
 
+
     /**
        only does a temp release if we're not nested and have a lock
      */
diff --git a/db/dbcommands.cpp b/db/dbcommands.cpp
index 2b78b62e6ee..8ebc53eebe7 100644
--- a/db/dbcommands.cpp
+++ b/db/dbcommands.cpp
@@ -761,8 +761,8 @@ namespace mongo {
                 b.append( "name", i->c_str() );
                 boost::intmax_t size = dbSize( i->c_str() );
                 b.append( "sizeOnDisk", (double) size );
-                setClient( i->c_str() );
-                b.appendBool( "empty", cc().database()->isEmpty() );
+                Client::Context ctx( *i );
+                b.appendBool( "empty", ctx.db()->isEmpty() );
                 totalSize += size;
                 dbInfos.push_back( b.obj() );
 
@@ -780,8 +780,8 @@ namespace mongo {
 
                 BSONObjBuilder b;
                 b << "name" << name << "sizeOnDisk" << double( 1 );
-                setClient( name.c_str() );
-                b.appendBool( "empty", cc().database()->isEmpty() );
+                Client::Context ctx( name );
+                b.appendBool( "empty", ctx.db()->isEmpty() );
 
                 dbInfos.push_back( b.obj() );
             }
@@ -927,9 +927,10 @@ namespace mongo {
             BSONObj max = jsobj.getObjectField( "max" );
             BSONObj keyPattern = jsobj.getObjectField( "keyPattern" );
 
+            Client::Context ctx( ns );
+            
             auto_ptr< Cursor > c;
             if ( min.isEmpty() && max.isEmpty() ) {
-                setClient( ns );
                 c = theDataFileMgr.findAll( ns );
             } else if ( min.isEmpty() || max.isEmpty() ) {
                 errmsg = "only one of min or max specified";
@@ -1039,7 +1040,6 @@ namespace mongo {
 
             string fromNs = string( realDbName ) + "." + from;
             string toNs = string( realDbName ) + "." + to;
-            massert( 10300 ,  "source collection " + fromNs + " does not exist", !setClient( fromNs.c_str() ) );
             NamespaceDetails *nsd = nsdetails( fromNs.c_str() );
             massert( 10301 ,  "source collection " + fromNs + " does not exist", nsd );
             long long excessSize = nsd->datasize - size * 2;
@@ -1061,7 +1061,7 @@ namespace mongo {
             }
 
             DBDirectClient client;
-            setClient( toNs.c_str() );
+            Client::Context ctx( toNs );
             BSONObjBuilder spec;
             spec.appendBool( "capped", true );
             spec.append( "size", double( size ) );
diff --git a/db/instance.cpp b/db/instance.cpp
index e02c51cd60c..dca9caa3221 100644
--- a/db/instance.cpp
+++ b/db/instance.cpp
@@ -176,6 +176,8 @@ namespace mongo {
         QueryResult* msgdata;
 
         Client& c = cc();
+        
+        Client::Context ctx( q.ns, dbpath, &lock );
 
         try {
             if (q.fields.get() && q.fields->errmsg)
@@ -192,7 +194,6 @@ namespace mongo {
                 }
             }
 
-            setClient( q.ns, dbpath, &lock );
             c.top.setRead();
             c.curop()->setNS(q.ns);
             msgdata = runQuery(m, q, op ).release();
@@ -290,7 +291,6 @@ namespace mongo {
         }
 
         Client& c = cc();
-        c.clearns();
         
         auto_ptr<CurOp> nestedOp;
         CurOp* currentOpP = c.curop();
@@ -414,7 +414,7 @@ namespace mongo {
             ss << ' ' << ms << "ms";
             mongo::log() << ss.str() << endl;
         }
-        Database *database = c.database();
+        Database *database = c.prevDatabase();
         if ( database && database->profile >= 1 ) {
             if ( database->profile >= 2 || ms >= cmdLine.slowMS ) {
                 // performance profiling is on
@@ -422,10 +422,8 @@ namespace mongo {
                     out() << "warning: not profiling because recursive lock" << endl;
                 }
                 else {
-                    string old_ns = c.ns();
-                    Database * old_db = c.database();
                     lk.releaseAndWriteLock();
-                    Client::Context c( old_ns , old_db );
+                    Client::Context c( "" , database );
                     profile(ss.str().c_str(), ms);
                 }
             }
@@ -452,20 +450,18 @@ namespace mongo {
        path - db directory
     */
     void closeDatabase( const char *db, const string& path ) {
-        Database *database = cc().database();
-        assert( database );
+        assertInWriteLock();
+        
+        Client::Context * ctx = cc().getContext();
+        assert( ctx );
+        assert( ctx->inDB( db , path ) );
+        Database *database = ctx->db();
         assert( database->name == db );
 
         if( BackgroundOperation::inProgForDb(db) ) { 
             log() << "warning: bg op in prog during close db? " << db << endl;
         }
 
-		/*
-        if ( string("local") != cl ) {
-            DBInfo i(cl);
-            i.dbDropped();
-			}*/
-
         /* important: kill all open cursors on the database */
         string prefix(db);
         prefix += '.';
@@ -475,7 +471,7 @@ namespace mongo {
 
         dbHolder.erase( db, path );
         delete database; // closes files
-        cc().clearns();
+        ctx->clear();
     }
 
     void receivedUpdate(Message& m, CurOp& op) {
@@ -483,9 +479,6 @@ namespace mongo {
         const char *ns = d.getns();
         assert(*ns);
         uassert( 10054 ,  "not master", isMasterNs( ns ) );
-        setClient(ns);
-        Client& client = cc();
-        client.top.setWrite();
         op.debug().str << ns << ' ';
         int flags = d.pullInt();
         BSONObj query = d.nextJsObj();
@@ -502,9 +495,13 @@ namespace mongo {
             string s = query.toString();
             /* todo: we shouldn't do all this ss stuff when we don't need it, it will slow us down. */
             op.debug().str << " query: " << s;
-            CurOp& currentOp = *client.curop();
-            currentOp.setQuery(query);
+            op.setQuery(query);
         }        
+
+        Client::Context ctx( ns );
+        Client& client = cc();
+        client.top.setWrite();
+
         UpdateResult res = updateObjects(ns, toupdate, query, upsert, multi, true, op.debug() );
         /* TODO FIX: recordUpdate should take a long int for parm #2 */
         recordUpdate( res.existing , (int) res.num ); // for getlasterror
@@ -515,7 +512,7 @@ namespace mongo {
         const char *ns = d.getns();
         assert(*ns);
         uassert( 10056 ,  "not master", isMasterNs( ns ) );
-        setClient(ns);
+        Client::Context ctx(ns);
         Client& client = cc();
         client.top.setWrite();
         int flags = d.pullInt();
@@ -540,7 +537,7 @@ namespace mongo {
         const char *ns = d.getns();
         StringBuilder& ss = curop.debug().str;
         ss << ns;
-        setClient(ns);
+        Client::Context ctx(ns);
         cc().top.setRead();
         int ntoreturn = d.pullInt();
         long long cursorid = d.pullInt64();
@@ -572,7 +569,7 @@ namespace mongo {
 		const char *ns = d.getns();
 		assert(*ns);
         uassert( 10058 ,  "not master", isMasterNs( ns ) );
-		setClient(ns);
+        Client::Context ctx(ns);
         cc().top.setWrite();
         op.debug().str << ns;
 		
@@ -618,7 +615,6 @@ namespace mongo {
     }
 
     bool DBDirectClient::call( Message &toSend, Message &response, bool assertOk ) {
-        SavedContext c;
         if ( lastError._get() )
             lastError.startRequest( toSend, lastError._get() );
         DbResponse dbResponse;
@@ -629,7 +625,6 @@ namespace mongo {
     }
 
     void DBDirectClient::say( Message &toSend ) {
-        SavedContext c;
         if ( lastError._get() )
             lastError.startRequest( toSend, lastError._get() );
         DbResponse dbResponse;
@@ -647,8 +642,6 @@ namespace mongo {
     }
 
 
-    DBDirectClient::AlwaysAuthorized DBDirectClient::SavedContext::always;
-
     DBClientBase * createDirectClient(){
         return new DBDirectClient();
     }
diff --git a/db/instance.h b/db/instance.h
index ce99f53f9db..2bf016d044c 100644
--- a/db/instance.h
+++ b/db/instance.h
@@ -124,53 +124,6 @@ namespace mongo {
             // don't need to piggy back when connected locally
             return say( toSend );
         }
-        class AlwaysAuthorized : public AuthenticationInfo {
-            virtual bool _isAuthorized( const char *dbname, int level ) {
-                return true;   
-            }
-        };
-
-        /* TODO: this looks bad that auth is set to always.  is that really always safe? */
-        class SavedContext {
-        public:
-            SavedContext() {
-                _save = dbMutex.atLeastReadLocked();
-
-                Client *c = currentClient.get();
-                oldAuth = c->ai;
-                // careful, don't want to free this:
-                c->ai = &always;
-
-                /* it only makes sense to manipulate a pointer - c->database() - if locked. 
-                   thus the _saved flag.
-                */
-                if( _save ) {
-                    if ( c->database() ) {
-                        dbMutex.assertAtLeastReadLocked();
-                        _oldName = c->database()->name;
-                    }
-                }
-            }
-            ~SavedContext() {
-                Client *c = currentClient.get();
-                c->ai = oldAuth;
-                if( _save ) {
-                    if ( !_oldName.empty() ) {
-                        dbMutex.assertAtLeastReadLocked();
-                        setClient( _oldName.c_str() );
-                    }
-                }
-                else {
-                    // defensive
-                    cc().clearns();
-                }
-            }
-        private:
-            bool _save;
-            static AlwaysAuthorized always;
-            AuthenticationInfo *oldAuth;
-            string _oldName;
-        };
     };
 
     extern int lockFile;
diff --git a/db/introspect.cpp b/db/introspect.cpp
index 9cb477d1db5..a041d489ffa 100644
--- a/db/introspect.cpp
+++ b/db/introspect.cpp
@@ -26,8 +26,7 @@
 
 namespace mongo {
 
-    void profile(const char *str,
-                 int millis)
+    void profile( const char *str, int millis)
     {
         BSONObjBuilder b;
         b.appendDate("ts", jsTime());
diff --git a/db/namespace.cpp b/db/namespace.cpp
index c3584d8fc1e..fc8cc7e0dd0 100644
--- a/db/namespace.cpp
+++ b/db/namespace.cpp
@@ -644,7 +644,7 @@ namespace mongo {
         stringstream spec;
         // 128MB
         spec << "{size:" << logSizeMb * 1024 * 1024 << ",capped:true,autoIndexId:false}";
-        setClient( _cll_ns.c_str() );
+        Client::Context ct( _cll_ns );
         string err;
         massert( 10347 ,  "Could not create log ns", userCreateNS( _cll_ns.c_str(), fromjson( spec.str() ), err, false ) );
         NamespaceDetails *d = nsdetails( _cll_ns.c_str() );
@@ -670,7 +670,7 @@ namespace mongo {
         assertInWriteLock();
         if ( !_cll_enabled )
             return;
-        setClient( _cll_ns.c_str() );
+        Client::Context ctx( _cll_ns );
         dropNS( _cll_ns );
     }
 
diff --git a/db/pdfile.cpp b/db/pdfile.cpp
index 5971185ba7a..0e9cd0e5c00 100644
--- a/db/pdfile.cpp
+++ b/db/pdfile.cpp
@@ -1654,11 +1654,16 @@ namespace mongo {
                                 "backup" : "$tmp" );
         BOOST_CHECK_EXCEPTION( boost::filesystem::create_directory( reservedPath ) );
         string reservedPathString = reservedPath.native_directory_string();
-        assert( setClient( dbName, reservedPathString.c_str() ) );
-
-        bool res = cloneFrom(localhost.c_str(), errmsg, dbName, 
-                             /*logForReplication=*/false, /*slaveok*/false, /*replauth*/false, /*snapshot*/false);
-        closeDatabase( dbName, reservedPathString.c_str() );
+        
+        bool res;
+        { // clone to temp location, which effectively does repair
+            Client::Context ctx( dbName, reservedPathString );
+            assert( ctx.justCreated() );
+            
+            res = cloneFrom(localhost.c_str(), errmsg, dbName, 
+                                 /*logForReplication=*/false, /*slaveok*/false, /*replauth*/false, /*snapshot*/false);
+            closeDatabase( dbName, reservedPathString.c_str() );
+        }
 
         if ( !res ) {
             problem() << "clone failed for " << dbName << " with error: " << errmsg << endl;
@@ -1667,7 +1672,7 @@ namespace mongo {
             return false;
         }
 
-        assert( !setClient( dbName ) );
+        Client::Context ctx( dbName );
         closeDatabase( dbName );
 
         if ( backupOriginalFiles ) {
@@ -1738,7 +1743,7 @@ namespace mongo {
         for( set< string >::iterator i = dbs.begin(); i != dbs.end(); ++i ) {
             string name = *i;
             log(2) << "DatabaseHolder::closeAll path:" << path << " name:" << name << endl;
-            setClient( name.c_str() , path );
+            Client::Context ctx( name , path );
             if( !force && BackgroundOperation::inProgForDb(name.c_str()) )
                 log() << "WARNING: can't close database " << name << "because a bg job is in progress - try killOp command" << endl;
             else
diff --git a/db/queryoptimizer.cpp b/db/queryoptimizer.cpp
index 499417a0f1c..214d99977a0 100644
--- a/db/queryoptimizer.cpp
+++ b/db/queryoptimizer.cpp
@@ -558,7 +558,7 @@ namespace mongo {
             return 0;
         }
         
-        setClient( ns );
+        Client::Context ctx( ns );
         IndexDetails *id = 0;
         NamespaceDetails *d = nsdetails( ns );
         if ( !d ) {
diff --git a/db/repl.cpp b/db/repl.cpp
index a54ce50e58b..f6f0b40e46c 100644
--- a/db/repl.cpp
+++ b/db/repl.cpp
@@ -541,12 +541,13 @@ namespace mongo {
         BSONObj o = jsobj();
         log( 1 ) << "Saving repl source: " << o << endl;
 
-        OpDebug debug;
-        setClient("local.sources");
-        UpdateResult res = updateObjects("local.sources", o, pattern, true/*upsert for pair feature*/, false,false,debug);
-        assert( ! res.mod );
-        assert( res.num == 1 );
-        cc().clearns();
+        {
+            OpDebug debug;
+            Client::Context ctx("local.sources");
+            UpdateResult res = updateObjects("local.sources", o, pattern, true/*upsert for pair feature*/, false,false,debug);
+            assert( ! res.mod );
+            assert( res.num == 1 );
+        }
 
         if ( replacing ) {
             /* if we were in "replace" mode, we now have synced up with the replacement,
@@ -578,13 +579,13 @@ namespace mongo {
        and cursor in effect.
     */
     void ReplSource::loadAll(SourceVector &v) {
+        Client::Context ctx("local.sources");
         SourceVector old = v;
         v.clear();
 
         bool gotPairWith = false;
 
         if ( !cmdLine.source.empty() ) {
-            setClient("local.sources");
             // --source <host> specified.
             // check that no items are in sources other than that
             // add if missing
@@ -626,7 +627,6 @@ namespace mongo {
         
         if ( replPair ) {
             const string &remote = replPair->remote;
-            setClient( "local.sources" );
             // --pairwith host specified.
             // check that no items are in sources other than that
             // add if missing
@@ -652,7 +652,6 @@ namespace mongo {
             }
         }
 
-        setClient("local.sources");
         auto_ptr<Cursor> c = findTableScan("local.sources", BSONObj());
         while ( c->ok() ) {
             ReplSource tmp(c->current());
@@ -668,7 +667,6 @@ namespace mongo {
             addSourceToList(v, tmp, c->current(), old);
             c->advance();
         }
-        cc().clearns();
 
         if ( !gotPairWith && replPair ) {
             /* add the --pairwith server */
@@ -732,7 +730,7 @@ namespace mongo {
     string ReplSource::resyncDrop( const char *db, const char *requester ) {
         log() << "resync: dropping database " << db << endl;
         string dummyns = string( db ) + ".";
-        setClient(dummyns.c_str());        
+        Client::Context ctx(dummyns);
         assert( cc().database()->name == db );
         dropDatabase(dummyns.c_str());
         return dummyns;
@@ -741,7 +739,7 @@ namespace mongo {
     /* grab initial copy of a database from the master */
     bool ReplSource::resync(string db) {
         string dummyNs = resyncDrop( db.c_str(), "internal" );
-        setClient( dummyNs.c_str() );
+        Client::Context ctx( dummyNs );
         {
             log() << "resync: cloning database " << db << endl;
             ReplInfo r("resync: cloning a database");
@@ -864,29 +862,21 @@ namespace mongo {
             throw SyncException();
         }
         
-        bool justCreated;
-        try {
-            justCreated = setClient(ns);
-        } catch ( AssertionException& ) {
-            problem() << "skipping bad(?) op in oplog, setClient() failed, ns: '" << ns << "'\n";
-            addDbNextPass.erase(clientName);
-            return;
-        }
+        Client::Context ctx( ns );
 
-        bool empty = cc().database()->isEmpty();
+        bool empty = ctx.db()->isEmpty();
         bool incompleteClone = incompleteCloneDbs.count( clientName ) != 0;
 
-        log( 6 ) << "ns: " << ns << ", justCreated: " << justCreated << ", empty: " << empty << ", incompleteClone: " << incompleteClone << endl;
-
-	// always apply admin command command
-	// this is a bit hacky -- the semantics of replication/commands aren't well specified
-	if ( strcmp( clientName, "admin" ) == 0 && *op.getStringField( "op" ) == 'c' ) {
-	  applyOperation( op );
-      cc().clearns();
-	  return;
-	}
+        log( 6 ) << "ns: " << ns << ", justCreated: " << ctx.justCreated() << ", empty: " << empty << ", incompleteClone: " << incompleteClone << endl;
         
-        if ( justCreated || empty || incompleteClone ) {
+        // always apply admin command command
+        // this is a bit hacky -- the semantics of replication/commands aren't well specified
+        if ( strcmp( clientName, "admin" ) == 0 && *op.getStringField( "op" ) == 'c' ) {
+            applyOperation( op );
+            return;
+        }
+        
+        if ( ctx.justCreated() || empty || incompleteClone ) {
             // we must add to incomplete list now that setClient has been called
             incompleteCloneDbs.insert( clientName );
             if ( nClonedThisPass ) {
@@ -901,9 +891,9 @@ namespace mongo {
                     log() << "An earlier initial clone of '" << clientName << "' did not complete, now resyncing." << endl;
                 }
                 save();
-                setClient( ns );
+                Client::Context ctx(ns);
                 nClonedThisPass++;
-                resync(cc().database()->name);
+                resync(ctx.db()->name);
                 addDbNextPass.erase(clientName);
                 incompleteCloneDbs.erase( clientName );
             }
@@ -927,7 +917,6 @@ namespace mongo {
             }
             addDbNextPass.erase( clientName );
         }
-        cc().clearns();
     }
 
     BSONObj ReplSource::idForOp( const BSONObj &op, bool &mod ) {
@@ -990,7 +979,7 @@ namespace mongo {
     }
     
     OpTime ReplSource::nextLastSavedLocalTs() const {
-        setClient( "local.oplog.$main" );
+        Client::Context ctx( "local.oplog.$main" );
         auto_ptr< Cursor > c = findTableScan( "local.oplog.$main", BSON( "$natural" << -1 ) );
         if ( c->ok() )
             return OpTime( c->current().getField( "ts" ).date() );        
@@ -1015,7 +1004,7 @@ namespace mongo {
     }
     
     bool ReplSource::updateSetsWithLocalOps( OpTime &localLogTail, bool mayUnlock ) {
-        setClient( "local.oplog.$main" );
+        Client::Context ctx( "local.oplog.$main" );
         auto_ptr< Cursor > localLog = findTableScan( "local.oplog.$main", BSON( "$natural" << -1 ) );
         OpTime newTail;
         for( ; localLog->ok(); localLog->advance() ) {
@@ -1385,7 +1374,7 @@ namespace mongo {
 
 // cached copies of these...so don't rename them
     NamespaceDetails *localOplogMainDetails = 0;
-    Database *localOplogClient = 0;
+    Database *localOplogDB = 0;
 
     void logOp(const char *opstr, const char *ns, const BSONObj& obj, BSONObj *patt, bool *b) {
         if ( master ) {
@@ -1447,14 +1436,14 @@ namespace mongo {
         Record *r;
         if ( strncmp( logNS, "local.", 6 ) == 0 ) { // For now, assume this is olog main
             if ( localOplogMainDetails == 0 ) {
-                setClient("local.");
-                localOplogClient = cc().database();
+                Client::Context ctx("local.");
+                localOplogDB = ctx.db();
                 localOplogMainDetails = nsdetails(logNS);
             }
-            cc().setns("", localOplogClient); // database = localOplogClient;
+            Client::Context ctx( "" , localOplogDB );
             r = theDataFileMgr.fast_oplog_insert(localOplogMainDetails, logNS, len);
         } else {
-            setClient( logNS );
+            Client::Context ctx( logNS );
             assert( nsdetails( logNS ) );
             r = theDataFileMgr.fast_oplog_insert( nsdetails( logNS ), logNS, len);
         }
@@ -1640,7 +1629,7 @@ namespace mongo {
         dblock lk;
 
         const char * ns = "local.oplog.$main";
-        setClient(ns);
+        Client::Context ctx(ns);
         
         if ( nsdetails( ns ) )
             return;
@@ -1673,7 +1662,6 @@ namespace mongo {
         BSONObj o = b.done();
         userCreateNS(ns, o, err, false);
         logOp( "n", "dummy", BSONObj() );
-        cc().clearns();
     }
     
     void startReplication() {
diff --git a/db/security.h b/db/security.h
index c5019d934ec..b5578f141d0 100644
--- a/db/security.h
+++ b/db/security.h
@@ -67,6 +67,7 @@ namespace mongo {
             if( authWriteOnly && ( 1 >= level ) ) return true;
 			if( m["admin"].level >= level ) return true;
 			if( m["local"].level >= level ) return true;
+            if( cc().isGod() ) return true;
 			if( isLocalHost ) { 
                 readlock l(""); 
                 Client::Context c("admin.system.users");
diff --git a/dbtests/btreetests.cpp b/dbtests/btreetests.cpp
index 5a0b15dfca1..3c9dc8defb5 100644
--- a/dbtests/btreetests.cpp
+++ b/dbtests/btreetests.cpp
@@ -28,14 +28,14 @@ namespace BtreeTests {
 
     class Base {
     public:
-        Base() {
+        Base() : 
+            _context( ns() ) {
+            
             {
                 bool f = false;
                 assert( f = true );
                 massert( 10402 , "assert is misdefined", f);
             }
-
-            setClient( ns() );
             BSONObjBuilder builder;
             builder.append( "ns", ns() );
             builder.append( "name", "testIndex" );
@@ -100,6 +100,7 @@ namespace BtreeTests {
         }
     private:
         dblock lk_;
+        Client::Context _context;
         IndexDetails idx_;
     };
 
diff --git a/dbtests/cursortests.cpp b/dbtests/cursortests.cpp
index 28a4ba45703..adb7881c495 100644
--- a/dbtests/cursortests.cpp
+++ b/dbtests/cursortests.cpp
@@ -42,7 +42,7 @@ namespace CursorTests {
                 BoundList b;
                 b.push_back( pair< BSONObj, BSONObj >( BSON( "" << 1 ), BSON( "" << 2 ) ) );
                 b.push_back( pair< BSONObj, BSONObj >( BSON( "" << 4 ), BSON( "" << 6 ) ) );
-                setClient( ns );
+                Client::Context ctx( ns );
                 BtreeCursor c( nsdetails( ns ), 1, nsdetails( ns )->idx(1), b, 1 );
                 ASSERT_EQUALS( "BtreeCursor a_1 multi", c.toString() );
                 double expected[] = { 1, 2, 4, 5, 6 };
@@ -72,7 +72,7 @@ namespace CursorTests {
                 b.push_back( pair< BSONObj, BSONObj >( BSON( "" << -50 ), BSON( "" << 2 ) ) );
                 b.push_back( pair< BSONObj, BSONObj >( BSON( "" << 40 ), BSON( "" << 60 ) ) );
                 b.push_back( pair< BSONObj, BSONObj >( BSON( "" << 109 ), BSON( "" << 200 ) ) );
-                setClient( ns );
+                Client::Context ctx( ns );
                 BtreeCursor c( nsdetails( ns ), 1, nsdetails( ns )->idx(1), b, 1 );
                 ASSERT_EQUALS( "BtreeCursor a_1 multi", c.toString() );
                 double expected[] = { 0, 1, 2, 109 };
@@ -99,7 +99,7 @@ namespace CursorTests {
                 BoundList b;
                 b.push_back( pair< BSONObj, BSONObj >( BSON( "" << 6 ), BSON( "" << 4 ) ) );
                 b.push_back( pair< BSONObj, BSONObj >( BSON( "" << 2 ), BSON( "" << 1 ) ) );
-                setClient( ns );
+                Client::Context ctx( ns );
                 BtreeCursor c( nsdetails( ns ), 1, nsdetails( ns )->idx(1), b, -1 );
                 ASSERT_EQUALS( "BtreeCursor a_1 reverse multi", c.toString() );
                 double expected[] = { 6, 5, 4, 2, 1 };
diff --git a/dbtests/namespacetests.cpp b/dbtests/namespacetests.cpp
index c820ca67f06..205c5d24223 100644
--- a/dbtests/namespacetests.cpp
+++ b/dbtests/namespacetests.cpp
@@ -30,9 +30,9 @@ namespace NamespaceTests {
     namespace IndexDetailsTests {
         class Base {
             dblock lk;
+            Client::Context _context;
         public:
-            Base() {
-                setClient( ns() );
+            Base() : _context(ns()){
             }
             virtual ~Base() {
                 if ( id_.info.isNull() )
@@ -571,9 +571,11 @@ namespace NamespaceTests {
     namespace NamespaceDetailsTests {
 
         class Base {
+            const char *ns_;
             dblock lk;
+            Client::Context _context;
         public:
-            Base( const char *ns = "unittests.NamespaceDetailsTests" ) : ns_( ns ) {}
+            Base( const char *ns = "unittests.NamespaceDetailsTests" ) : ns_( ns ) , _context( ns ) {}
             virtual ~Base() {
                 if ( !nsd() )
                     return;
@@ -585,7 +587,6 @@ namespace NamespaceTests {
         protected:
             void create() {
                 dblock lk;
-                setClient( ns() );
                 string err;
                 ASSERT( userCreateNS( ns(), fromjson( spec() ), err, false ) );
             }
@@ -627,8 +628,6 @@ namespace NamespaceTests {
                 b.append( "a", as );
                 return b.obj();
             }
-        private:
-            const char *ns_;
         };
 
         class Create : public Base {
diff --git a/dbtests/pdfiletests.cpp b/dbtests/pdfiletests.cpp
index 17659c0ffeb..fbacf8b1e25 100644
--- a/dbtests/pdfiletests.cpp
+++ b/dbtests/pdfiletests.cpp
@@ -31,8 +31,7 @@ namespace PdfileTests {
 
         class Base {
         public:
-            Base() {
-                setClient( ns() );
+            Base() : _context( ns() ){
             }
             virtual ~Base() {
                 if ( !nsd() )
@@ -99,6 +98,7 @@ namespace PdfileTests {
             }
         private:
             dblock lk_;
+            Client::Context _context;
         };
 
         class Empty : public Base {
@@ -269,8 +269,7 @@ namespace PdfileTests {
     namespace Insert {
         class Base {
         public:
-            Base() {
-                setClient( ns() );
+            Base() : _context( ns() ){
             }
             virtual ~Base() {
                 if ( !nsd() )
@@ -287,6 +286,7 @@ namespace PdfileTests {
             }
         private:
             dblock lk_;
+            Client::Context _context;
         };
         
         class UpdateDate : public Base {
diff --git a/dbtests/perf/perftest.cpp b/dbtests/perf/perftest.cpp
index 6fe9d6aacfb..02b2fadd766 100644
--- a/dbtests/perf/perftest.cpp
+++ b/dbtests/perf/perftest.cpp
@@ -623,7 +623,7 @@ namespace Plan {
                 client_->ensureIndex( ns_.c_str(), BSON( ( names + i ) << 1 ), false, names + i );
             }
             lk_.reset( new dblock );
-            setClient( ns_.c_str() );
+            Client::Context ctx( ns_ );
             hint_ = BSON( "hint" << BSON( "a" << 1 ) );
             hintElt_ = hint_.firstElement();
         }
@@ -646,9 +646,9 @@ namespace Plan {
                 client_->ensureIndex( ns_.c_str(), BSON( ( names + i ) << 1 ), false, names + i );
             }
             lk_.reset( new dblock );
-            setClient( ns_.c_str() );
         }
         void run() {
+            Client::Context ctx( ns_ );
             for( int i = 0; i < 10000; ++i )
                 QueryPlanSet s( ns_.c_str(), BSONObj(), BSON( "a" << 1 ) );
         }
@@ -665,9 +665,9 @@ namespace Plan {
                 client_->ensureIndex( ns_.c_str(), BSON( ( names + i ) << 1 ), false, names + i );
             }
             lk_.reset( new dblock );
-            setClient( ns_.c_str() );
         }
         void run() {
+            Client::Context ctx( ns_.c_str() );
             for( int i = 0; i < 10000; ++i )
                 QueryPlanSet s( ns_.c_str(), BSON( "a" << 1 ), BSONObj() );
         }
diff --git a/dbtests/queryoptimizertests.cpp b/dbtests/queryoptimizertests.cpp
index c9465f3479e..c7d09cdc1d9 100644
--- a/dbtests/queryoptimizertests.cpp
+++ b/dbtests/queryoptimizertests.cpp
@@ -316,8 +316,7 @@ namespace QueryOptimizerTests {
     namespace QueryPlanTests {
         class Base {
         public:
-            Base() : indexNum_( 0 ) {
-                setClient( ns() );
+            Base() : _ctx( ns() ) , indexNum_( 0 ) {
                 string err;
                 userCreateNS( ns(), BSONObj(), err, false );
             }
@@ -357,6 +356,7 @@ namespace QueryOptimizerTests {
             }
         private:
             dblock lk_;
+            Client::Context _ctx;
             int indexNum_;
             static DBDirectClient client_;
         };
@@ -595,8 +595,7 @@ namespace QueryOptimizerTests {
     namespace QueryPlanSetTests {
         class Base {
         public:
-            Base() {
-                setClient( ns() );
+            Base() : _context( ns() ){
                 string err;
                 userCreateNS( ns(), BSONObj(), err, false );
             }
@@ -625,6 +624,7 @@ namespace QueryOptimizerTests {
             static NamespaceDetails *nsd() { return nsdetails( ns() ); }
         private:
             dblock lk_;
+            Client::Context _context;
         };
         
         class NoIndexes : public Base {
diff --git a/dbtests/querytests.cpp b/dbtests/querytests.cpp
index 4681bf0adfd..2a25b206e9a 100644
--- a/dbtests/querytests.cpp
+++ b/dbtests/querytests.cpp
@@ -31,10 +31,9 @@ namespace QueryTests {
 
     class Base {
         dblock lk;
+        Client::Context _context;
     public:
-        Base() {
-            dblock lk;
-            setClient( ns() );
+        Base() : _context( ns() ){
             addIndex( fromjson( "{\"a\":1}" ) );
         }
         ~Base() {
@@ -608,7 +607,7 @@ namespace QueryTests {
     public:
         void run() {
             dblock lk;
-            setClient( "unittests.DirectLocking" );
+            Client::Context ctx( "unittests.DirectLocking" );
             client().remove( "a.b", BSONObj() );
             ASSERT_EQUALS( "unittests", cc().database()->name );
         }
@@ -725,7 +724,7 @@ namespace QueryTests {
             string err;
 
             writelock lk("");            
-            setClient( "unittests" );
+            Client::Context ctx( "unittests" );
 
             ASSERT( userCreateNS( ns() , fromjson( "{ capped : true , size : 2000 }" ) , err , false ) );
             for ( int i=0; i<100; i++ ){
@@ -770,7 +769,7 @@ namespace QueryTests {
 
         void run(){
             writelock lk("");
-            setClient( "unittests" );
+            Client::Context ctx( "unittests" );
             
             for ( int i=0; i<50; i++ ){
                 insert( ns() , BSON( "_id" << i << "x" << i * 2 ) );
@@ -836,7 +835,7 @@ namespace QueryTests {
 
         void run(){
             writelock lk("");
-            setClient( "unittests" );
+            Client::Context ctx( "unittests" );
 
             for ( int i=0; i<1000; i++ ){
                 insert( ns() , BSON( "_id" << i << "x" << i * 2 ) );
@@ -860,7 +859,7 @@ namespace QueryTests {
 
         void run(){
             writelock lk("");
-            setClient( "unittests" );
+            Client::Context ctx( "unittests" );
             
             for ( int i=0; i<1000; i++ ){
                 insert( ns() , BSON( "_id" << i << "x" << i * 2 ) );
diff --git a/dbtests/repltests.cpp b/dbtests/repltests.cpp
index 244c3079e79..3015a877cde 100644
--- a/dbtests/repltests.cpp
+++ b/dbtests/repltests.cpp
@@ -37,12 +37,12 @@ namespace ReplTests {
     }    
     
     class Base {
+        dblock lk;
+        Client::Context _context;
     public:
-        Base() {
+        Base() : _context( ns() ){
             master = true;
             createOplog();
-            dblock lk;
-            setClient( ns() );
             ensureHaveIdIndex( ns() );
         }
         ~Base() {
@@ -88,7 +88,7 @@ namespace ReplTests {
         int count() const {
             int count = 0;
             dblock lk;
-            setClient( ns() );
+            Client::Context ctx( ns() );
             auto_ptr< Cursor > c = theDataFileMgr.findAll( ns() );
             for(; c->ok(); c->advance(), ++count ) {
 //                cout << "obj: " << c->current().toString() << endl;
@@ -97,7 +97,7 @@ namespace ReplTests {
         }
         static int opCount() {
             dblock lk;
-            setClient( cllNS() );
+            Client::Context ctx( cllNS() );
             int count = 0;
             for( auto_ptr< Cursor > c = theDataFileMgr.findAll( cllNS() ); c->ok(); c->advance() )
                 ++count;
@@ -111,17 +111,21 @@ namespace ReplTests {
                 }
             };
             dblock lk;
-            setClient( cllNS() );
             vector< BSONObj > ops;
-            for( auto_ptr< Cursor > c = theDataFileMgr.findAll( cllNS() ); c->ok(); c->advance() )
-                ops.push_back( c->current() );
-            setClient( ns() );
-            for( vector< BSONObj >::iterator i = ops.begin(); i != ops.end(); ++i )
-                Applier::apply( *i );
+            {
+                Client::Context ctx( cllNS() );
+                for( auto_ptr< Cursor > c = theDataFileMgr.findAll( cllNS() ); c->ok(); c->advance() )
+                    ops.push_back( c->current() );
+            }
+            {
+                Client::Context ctx( ns() );
+                for( vector< BSONObj >::iterator i = ops.begin(); i != ops.end(); ++i )
+                    Applier::apply( *i );
+            }
         }
         static void printAll( const char *ns ) {
             dblock lk;
-            setClient( ns );
+            Client::Context ctx( ns );
             auto_ptr< Cursor > c = theDataFileMgr.findAll( ns );
             vector< DiskLoc > toDelete;
             out() << "all for " << ns << endl;
@@ -132,7 +136,7 @@ namespace ReplTests {
         // These deletes don't get logged.
         static void deleteAll( const char *ns ) {
             dblock lk;
-            setClient( ns );
+            Client::Context ctx( ns );
             auto_ptr< Cursor > c = theDataFileMgr.findAll( ns );
             vector< DiskLoc > toDelete;
             for(; c->ok(); c->advance() ) {
@@ -144,7 +148,7 @@ namespace ReplTests {
         }
         static void insert( const BSONObj &o, bool god = false ) {
             dblock lk;
-            setClient( ns() );
+            Client::Context ctx( ns() );
             theDataFileMgr.insert( ns(), o.objdata(), o.objsize(), god );
         }
         static BSONObj wid( const char *json ) {
@@ -908,7 +912,7 @@ namespace ReplTests {
     class DbIdsTest {
     public:
         void run() {
-            setClient( "unittests.repltest.DbIdsTest" );
+            Client::Context ctx( "unittests.repltest.DbIdsTest" );
             
             s_.reset( new DbIds( "local.temp.DbIdsTest" ) );
             s_->reset();
@@ -983,7 +987,7 @@ namespace ReplTests {
     class IdTrackerTest {
     public:
         void run() {
-            setClient( "unittests.repltests.IdTrackerTest" );
+            Client::Context ctx( "unittests.repltests.IdTrackerTest" );
             
             ASSERT( s_.inMem() );
             s_.reset( 4 * sizeof( BSONObj ) - 1 );