/usr/include/mongo/s/grid.h is in mongodb-dev 1:2.4.9-1ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 | // 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( const std::string& db );
/**
* removes db entry - only this DBConfig object will be removed,
* other DBConfigs which may have been created in the meantime will not be harmed
* on next getDBConfig call will fetch from db
*
* Using this method avoids race conditions where multiple threads detect a database
* reload has failed.
*
* Example : N threads receive version exceptions and dbConfig.reload(), while
* simultaneously a dropDatabase is occurring. In the meantime, the dropDatabase call
* attempts to create a DBConfig object if one does not exist, to load the db info,
* but the config is repeatedly deleted as soon as it is created. Using this method
* prevents the deletion of configs we don't know about.
*
*/
void removeDBIfExists( const DBConfig& database );
/**
* @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 running
* 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 omitted, 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 string& ns = "", BSONObj* balancerDocOut = 0 ) const;
/**
*
* Obtain grid configuration and settings data.
*
* @param name identifies a particular type of configuration data.
* @return a BSON object containing the requested data.
*/
BSONObj getConfigSetting( const std::string& name ) 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
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