Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
tag: r1.9.0
Fetching contributors…

Octocat-spinner-32-eaf2f5

Cannot retrieve contributors at this time

file 127 lines (101 sloc) 4.584 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126
// grid.h

/**
* Copyright (C) 2010 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/>.
*/

#pragma once

#include <boost/date_time/posix_time/posix_time.hpp>

#include "../util/time_support.h"
#include "../util/concurrency/mutex.h"

#include "config.h" // DBConfigPtr

namespace mongo {

    /**
* stores meta-information about the grid
* TODO: used shard_ptr for DBConfig pointers
*/
    class Grid {
    public:
        Grid() : _lock( "Grid" ) , _allowLocalShard( true ) { }

        /**
* gets the config the db.
* will return an empty DBConfig if not in db already
*/
        DBConfigPtr getDBConfig( string ns , bool create=true , const string& shardNameHint="" );

        /**
* removes db entry.
* on next getDBConfig call will fetch from db
*/
        void removeDB( string db );

        /**
* @return true if shards and config servers are allowed to use 'localhost' in address
*/
        bool allowLocalHost() const;

        /**
* @param whether to allow shards and config servers to use 'localhost' in address
*/
        void setAllowLocalHost( bool allow );

        /**
*
* addShard will create a new shard in the grid. It expects a mongod process to be runing
* on the provided address. Adding a shard that is a replica set is supported.
*
* @param name is an optional string with the name of the shard. if ommited, grid will
* generate one and update the parameter.
* @param servers is the connection string of the shard being added
* @param maxSize is the optional space quota in bytes. Zeros means there's no limitation to
* space usage
* @param errMsg is the error description in case the operation failed.
* @return true if shard was successfully added.
*/
        bool addShard( string* name , const ConnectionString& servers , long long maxSize , string& errMsg );

        /**
* @return true if the config database knows about a host 'name'
*/
        bool knowAboutShard( const string& name ) const;

        /**
* @return true if the chunk balancing functionality is enabled
*/
        bool shouldBalance() const;

        unsigned long long getNextOpTime() const;
        
        void flushConfig();

        // exposed methods below are for testing only

        /**
* @param balancerDoc bson that may contain a window of time for the balancer to work
* format { ... , activeWindow: { start: "8:30" , stop: "19:00" } , ... }
* @return true if there is no window of time specified for the balancer or it we're currently in it
*/
        static bool _inBalancingWindow( const BSONObj& balancerDoc , const boost::posix_time::ptime& now );

    private:
        mongo::mutex _lock; // protects _databases; TODO: change to r/w lock ??
        map<string, DBConfigPtr > _databases; // maps ns to DBConfig's
        bool _allowLocalShard; // can 'localhost' be used in shard addresses?

        /**
* @param name is the chose name for the shard. Parameter is mandatory.
* @return true if it managed to generate a shard name. May return false if (currently)
* 10000 shard
*/
        bool _getNewShardName( string* name ) const;

        /**
* @return whether a give dbname is used for shard "local" databases (e.g., admin or local)
*/
        static bool _isSpecialLocalDB( const string& dbName );

        /**
* @param balancerDoc bson that may contain a marker to stop the balancer
* format { ... , stopped: [ "true" | "false" ] , ... }
* @return true if the marker is present and is set to true
*/
        static bool _balancerStopped( const BSONObj& balancerDoc );

    };

    extern Grid grid;

} // namespace mongo
Something went wrong with that request. Please try again.