sharding version management for mongod

SConstruct

@@ -139,6 +139,10 @@ coreServerFiles = [ "util/message_server_port.cpp" , "util/message_server_asio.c
 
 serverOnlyFiles = Split( "db/query.cpp db/introspect.cpp db/btree.cpp db/clientcursor.cpp db/javajs.cpp db/tests.cpp db/repl.cpp db/btreecursor.cpp db/cloner.cpp db/namespace.cpp db/matcher.cpp db/dbcommands.cpp db/dbeval.cpp db/dbwebserver.cpp db/dbinfo.cpp db/dbhelpers.cpp db/instance.cpp db/pdfile.cpp db/cursor.cpp db/security_commands.cpp db/security.cpp util/miniwebserver.cpp db/storage.cpp db/reccache.cpp db/queryoptimizer.cpp" )
 
+coreShardFiles = []
+shardServerFiles = coreShardFiles + Glob( "s/strategy*.cpp" ) + [ "s/commands.cpp" , "s/request.cpp" ,  "s/cursors.cpp" ,  "s/server.cpp" ] + [ "s/shard.cpp" , "s/shardkey.cpp" , "s/config.cpp" ]
+serverOnlyFiles += coreShardFiles + [ "s/commands_db.cpp" ]
+
 allClientFiles = commonFiles + coreDbFiles + [ "client/clientOnly.cpp" , "client/gridfs.cpp" ];
 
 onlyServer = len( COMMAND_LINE_TARGETS ) == 0 or ( len( COMMAND_LINE_TARGETS ) == 1 and str( COMMAND_LINE_TARGETS[0] ) == "mongod" )
@@ -522,7 +526,7 @@ env.Program( "mongoimportjson" , allToolFiles + [ "tools/importJSON.cpp" ] )
 env.Program( "mongofiles" , allToolFiles + [ "tools/files.cpp" ] )
 
 # mongos
-mongos = env.Program( "mongos" , commonFiles + coreDbFiles + coreServerFiles + Glob( "s/*.cpp" ) )
+mongos = env.Program( "mongos" , commonFiles + coreDbFiles + coreServerFiles + shardServerFiles )
 
 # c++ library
 clientLibName = str( env.Library( "mongoclient" , allClientFiles )[0] )

jstests/sharding/version1.js

@@ -0,0 +1,20 @@
+// version1.js
+
+s = new ShardingTest( "version1" , 1 , 2 )
+
+a = s._connections[0].getDB( "admin" );
+
+assert( a.runCommand( { "setShardVersion" : "alleyinsider.foo" , configdb : s._configDB } ).ok == 0 );
+assert( a.runCommand( { "setShardVersion" : "alleyinsider.foo" , configdb : s._configDB , version : "a" } ).ok == 0 );
+assert( a.runCommand( { "setShardVersion" : "alleyinsider.foo" , configdb : s._configDB , version : 2 } ).ok == 1 );
+assert( a.runCommand( { "setShardVersion" : "alleyinsider.foo" , configdb : "a" , version : 2 } ).ok == 0 );
+
+assert( a.runCommand( { "setShardVersion" : "alleyinsider.foo" , configdb : s._configDB , version : 2 } ).ok == 1 );
+assert( a.runCommand( { "setShardVersion" : "alleyinsider.foo" , configdb : s._configDB , version : 1 } ).ok == 0 );
+
+assert.eq( a.runCommand( { "setShardVersion" : "alleyinsider.foo" , configdb : s._configDB , version : 3 } ).oldVersion.i , 2 , "oldVersion" );
+
+assert.eq( a.runCommand( { "getShardVersion" : "alleyinsider.foo" } ).mine.i , 3 , "my get version A" );
+assert.eq( a.runCommand( { "getShardVersion" : "alleyinsider.foo" } ).global.i , 3 , "my get version B" );
+
+s.stop();

s/commands_db.cpp

@@ -0,0 +1,165 @@
+// commands_db.cpp
+
+/**
+*    Copyright (C) 2008 10gen Inc.
+*
+*    This program is free software: you can redistribute it and/or  modify
+*    it under the terms of the GNU Affero General Public License, version 3,
+*    as published by the Free Software Foundation.
+*
+*    This program is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU Affero General Public License for more details.
+*
+*    You should have received a copy of the GNU Affero General Public License
+*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+
+/**
+   these are commands that live in mongod
+   mostly around shard management and checking
+ */
+
+#include "stdafx.h"
+#include <map>
+#include <string>
+
+#include "../db/commands.h"
+#include "../db/jsobj.h"
+
+using namespace std;
+
+namespace mongo {
+    
+    typedef map<string,unsigned long long> NSVersions;
+    
+    NSVersions myVersions;
+    boost::thread_specific_ptr<NSVersions> clientShardVersions;
+    string shardConfigServer;
+
+
+    class MongodShardCommand : public Command {
+    public:
+        MongodShardCommand( const char * n ) : Command( n ){
+        }
+        virtual bool slaveOk(){
+            return false;
+        }
+        virtual bool adminOnly() {
+            return true;
+        }
+    };
+
+    // setShardVersion( ns )
+    
+    class SetShardVersion : public MongodShardCommand {
+    public:
+        SetShardVersion() : MongodShardCommand("setShardVersion"){}
+
+        virtual void help( stringstream& help ) const {
+            help << " example: { setShardVersion : 'alleyinsider.foo' , version : 1 , configdb : '' } ";
+        }
+        
+        bool run(const char *cmdns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool){
+            
+            string configdb = cmdObj["configdb"].valuestrsafe();
+            { // configdb checking
+                if ( configdb.size() == 0 ){
+                    errmsg = "no configdb";
+                    return false;
+                }
+                
+                if ( shardConfigServer.size() == 0 ){
+                    shardConfigServer = configdb;
+                }
+                else if ( shardConfigServer != configdb ){
+                    errmsg = "specified a different configdb!";
+                    return false;
+                }
+            }
+            
+            unsigned long long version;
+            {
+                BSONElement e = cmdObj["version"];
+                if ( e.eoo() ){
+                    errmsg = "no version";
+                    return false;
+                }
+                else if ( e.isNumber() )
+                    version = (unsigned long long)e.number();
+                else if ( e.type() == Date || e.type() == Timestamp )
+                    version = e.date();
+                else {
+                    errmsg = "version is not a numberic type";
+                    return false;
+                }
+                
+            }
+
+            NSVersions * versions = clientShardVersions.get();
+            
+            if ( ! versions ){
+                log(1) << "entering shard mode for connection" << endl;
+                versions = new NSVersions();
+                clientShardVersions.reset( versions );
+            }
+            
+            string ns = cmdObj["setShardVersion"].valuestrsafe();
+            if ( ns.size() == 0 ){
+                errmsg = "need to speciy fully namespace";
+                return false;
+            }
+
+            unsigned long long& oldVersion = (*versions)[ns];
+            if ( version < oldVersion ){
+                errmsg = "going to older version for you!";
+                return false;
+            }
+
+            unsigned long long& myVersion = myVersions[ns];
+            if ( version < myVersion ){
+                errmsg = "going to older version for global";
+                return false;
+            }
+            
+            result.appendTimestamp( "oldVersion" , oldVersion );
+            oldVersion = version;
+            myVersion = version;
+
+            result.append( "ok" , 1 );
+            return 1;
+        }
+        
+    } setShardVersion;
+    
+    class GetShardVersion : public MongodShardCommand {
+    public:
+        GetShardVersion() : MongodShardCommand("getShardVersion"){}
+
+        virtual void help( stringstream& help ) const {
+            help << " example: { getShardVersion : 'alleyinsider.foo'  } ";
+        }
+
+        bool run(const char *cmdns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool){
+            string ns = cmdObj["getShardVersion"].valuestrsafe();
+            if ( ns.size() == 0 ){
+                errmsg = "need to speciy fully namespace";
+                return false;
+            }
+            
+            result.appendTimestamp( "global" , myVersions[ns] );
+            if ( clientShardVersions.get() )
+                result.appendTimestamp( "mine" , (*clientShardVersions.get())[ns] );
+            else 
+                result.appendTimestamp( "mine" , 0 );
+            
+            result.append( "ok" , 1 );
+            return true;
+        }
+        
+    } getShardVersion;
+
+
+}