コンソール画面でのコマンド操作
MongoDBに対する操作は、基本的にコンソール画面から行うので、コマンドさえ理解出来れば大抵のことが出来ます。というわけで今回はコマンドの説明。
mongod/mongosへ接続
何はともあれ接続。コマンドは以下の通り。
> MONGODB_HOME/bin/mongo.exe [ホスト名]:[ポート番号]/[データベース名]
あとから接続先のデータベースを変更することも出来る。
> use [データベース名]
mongod/mongosの両方に接続できるけど、Sharding構成の場合は必ずmongosに接続すること。mongodに接続した場合は、他のmongodにShardingされている情報が取得出来ない。
mongosに接続した場合
> MONGODB_HOME/bin/mongo.exe localhost:28101/hoge MongoDB shell version: 1.8.1 connecting to: localhost:28101/hoge > db.user.count(); 300000
mongodに接続した場合
> MONGODB_HOME/bin/mongo.exe localhost:28201/hoge MongoDB shell version: 1.8.1 connecting to: localhost:28201/hoge > db.user.count(); 179974
ちなみに、Replica Set構成でPRIMARY以外に接続すると、コマンド実行時にPRIMARYじゃないとエラーメッセージが表示される。
MONGODB_HOME/bin/mongo.exe localhost:28212/hoge
MongoDB shell version: 1.8.1
connecting to: localhost:28212/hoge
s2:SECONDARY> db.user.count();
Tue Apr 19 00:42:17 uncaught exception: count failed: { "errmsg" : "not master", "ok" : 0 }
困ったらhelp
ほとんどのコマンドはhelpで説明が表示されるので、困ったらhelp。
> help
db.help() help on db methods
db.mycoll.help() help on collection methods
rs.help() help on replica set methods
help connect connecting to a db help
help admin administrative help
help misc misc things to know
help mr mapreduce help
show dbs show database names
show collections show collections in current database
show users show users in current database
show profile show most recent system.profile entries with time >= 1ms
use <db_name> set current database
db.foo.find() list objects in collection foo
db.foo.find( { a : 1 } ) list objects in foo where a == 1
it result of the last line evaluated; use to further iterate
DBQuery.shellBatchSize = x set default number of items to display on shell
exit quit the mongo shellデータベースの操作について分からない場合は、db.help()を実行する。
> db.help();
DB methods:
db.addUser(username, password[, readOnly=false])
db.auth(username, password)
db.cloneDatabase(fromhost)
db.commandHelp(name) returns the help for the command
db.copyDatabase(fromdb, todb, fromhost)
db.createCollection(name, { size : ..., capped : ..., max : ... } )
db.currentOp() displays the current operation in the db
db.dropDatabase()
db.eval(func, args) run code server-side
db.getCollection(cname) same as db['cname'] or db.cname
db.getCollectionNames()
db.getLastError() - just returns the err msg string
db.getLastErrorObj() - return full status object
db.getMongo() get the server connection object
db.getMongo().setSlaveOk() allow this connection to read from the nonmaster member of a replica pair
db.getName()
db.getPrevError()
db.getProfilingLevel() - deprecated
db.getProfilingStatus() - returns if profiling is on and slow threshold
db.getReplicationInfo()
db.getSiblingDB(name) get the db at the same server as this one
db.isMaster() check replica primary status
db.killOp(opid) kills the current operation in the db
db.listCommands() lists all the db commands
db.printCollectionStats()
db.printReplicationInfo()
db.printSlaveReplicationInfo()
db.printShardingStatus()
db.removeUser(username)
db.repairDatabase()
db.resetError()
db.runCommand(cmdObj) run a database command. if cmdObj is a string, turns it into { cmdObj : 1 }
db.serverStatus()
db.setProfilingLevel(level,<slowms>) 0=off 1=slow 2=all
db.shutdownServer()
db.stats()
db.version() current version of the server
db.getMongo().setSlaveOk() allow queries on a replication slave serverさらに、コレクションの操作が分からない場合は、db.[コレクション名].help()を実行する。
> show collections
system.indexes
user
> db.user.help();
DBCollection help
db.user.find().help() - show DBCursor help
db.user.count()
db.user.dataSize()
db.user.distinct( key ) - eg. db.user.distinct( 'x' )
db.user.drop() drop the collection
db.user.dropIndex(name)
db.user.dropIndexes()
db.user.ensureIndex(keypattern[,options]) - options is an object with these possible fields: name, unique, dropDups
db.user.reIndex()
db.user.find([query],[fields]) - query is an optional query filter. fields is optional set of fields to return.
e.g. db.user.find( {x:77} , {name:1, x:1} )
db.user.find(...).count()
db.user.find(...).limit(n)
db.user.find(...).skip(n)
db.user.find(...).sort(...)
db.user.findOne([query])
db.user.findAndModify( { update : ... , remove : bool [, query: {}, sort: {}, 'new': false] } )
db.user.getDB() get DB object associated with collection
db.user.getIndexes()
db.user.group( { key : ..., initial: ..., reduce : ...[, cond: ...] } )
db.user.mapReduce( mapFunction , reduceFunction , <optional params> )
db.user.remove(query)
db.user.renameCollection( newName , <dropTarget> ) renames the collection.
db.user.runCommand( name , <options> ) runs a db command with the given name where the first param is the collection name
db.user.save(obj)
db.user.stats()
db.user.storageSize() - includes free space allocated to this collection
db.user.totalIndexSize() - size in bytes of all the indexes
db.user.totalSize() - storage allocated for all data and indexes
db.user.update(query, object[, upsert_bool, multi_bool])
db.user.validate() - SLOW
db.user.getShardVersion() - only for use with shardingReplica Setに関するヘルプはrs.help()を実行する。
> rs.help()
rs.status() { replSetGetStatus : 1 } checks repl set status
rs.initiate() { replSetInitiate : null } initiates set with default settings
rs.initiate(cfg) { replSetInitiate : cfg } initiates set with configuration cfg
rs.conf() get the current configuration object from local.system.replset
rs.reconfig(cfg) updates the configuration of a running replica set with cfg (disconnects)
rs.add(hostportstr) add a new member to the set with default attributes (disconnects)
rs.add(membercfgobj) add a new member to the set with extra attributes (disconnects)
rs.addArb(hostportstr) add a new member which is arbiterOnly:true (disconnects)
rs.stepDown([secs]) step down as primary (momentarily) (disconnects)
rs.freeze(secs) make a node ineligible to become primary for the time specified
rs.remove(hostportstr) remove a host from the replica set (disconnects)
rs.slaveOk() shorthand for db.getMongo().setSlaveOk()
db.isMaster() check who is primary
reconfiguration helpers disconnect from the database so the shell will display
an error, even if the command succeeds.
see also http://<mongod_host>:28017/_replSet for additional diagnostic infoあとはshow xxxでデータベースやコレクションの情報を表示したりと。
> show dbs; admin (empty) config 0.015625GB hoge 0.1875GB > show collections; system.indexes user
分かりづらいのはコマンドを実行するdb.runCommand(cmdObj)。db.listCommands()でコマンドの一覧が表示されるため、ここから必要なコマンドを探す。
> db.listCommands();
addShard: no-lock adminOnly slaveOk
add a new shard to the system
applyOps: no-lock
no help defined
availableQueryOptions: no-lock
no help defined
buildInfo: no-lock adminOnly slaveOk
get version #, etc.
{ buildinfo:1 }
closeAllDatabases: no-lock adminOnly slaveOk
Not supported sharded
collStats: no-lock
no help defined
connPoolStats: no-lock
stats about connection pool
connPoolSync: no-lock
internal
convertToCapped: no-lock
no help defined
copydb: no-lock
no help defined
count: no-lock
no help defined
cursorInfo: no-lock
example: { cursorInfo : 1 }
dataSize: no-lock
no help defined
dbStats: no-lock
no help defined
distinct: no-lock
{ distinct : 'collection name' , key : 'a.b' , query : {} }
drop: no-lock
no help defined
dropDatabase: no-lock
no help defined
dropIndexes: no-lock
no help defined
enableSharding: no-lock adminOnly slaveOk
Enable sharding for a db. (Use 'shardcollection' command afterwards.)
{ enablesharding : "<dbname>" }
features: no-lock
return build level feature settings
filemd5: no-lock
example: { filemd5 : ObjectId(aaaaaaa) , root : "fs" }
findAndModify: no-lock
no help defined
forceerror: no-lock
for testing purposes only. forces a user assertion exception
fsync: no-lock adminOnly slaveOk
no help defined
geoNear: no-lock
http://www.mongodb.org/display/DOCS/Geospatial+Indexing#GeospatialIndexing-geoNearCommand
getCmdLineOpts: no-lock adminOnly slaveOk
get argv
getLastError: no-lock
check for an error on the last command executed
getParameter: no-lock adminOnly slaveOk
get administrative option(s)
example:
{ getParameter:1, notablescan:1 }
supported so far:
quiet
notablescan
logLevel
syncdelay
{ getParameter:'*' } to get everything
getPrevError: no-lock
get previous error (since last reseterror command)
getShardMap: no-lock adminOnly slaveOk
internal
getShardVersion: no-lock adminOnly slaveOk
example: { getShardVersion : 'alleyinsider.foo' }
group: no-lock
no help defined
isMaster: no-lock
test if this is master half of a replica pair
isdbgrid: no-lock
no help defined
listCommands: no-lock
get a list of all db commands
listDatabases: no-lock adminOnly slaveOk
list databases on cluster
listShards: no-lock adminOnly slaveOk
list all shards of the system
logRotate: no-lock adminOnly slaveOk
no help defined
mapreduce: no-lock
no help defined
moveChunk: no-lock adminOnly slaveOk
{ movechunk : 'test.foo' , find : { num : 1 } , to : 'localhost:30001' }
movePrimary: no-lock adminOnly slaveOk
example: { moveprimary : 'foo' , to : 'localhost:9999' }
netstat: no-lock adminOnly slaveOk
shows status/reachability of servers in the cluster
ping: no-lock
a way to check that the server is alive. responds immediately even if server is in a db lock.
reIndex: no-lock
no help defined
removeShard: no-lock adminOnly slaveOk
remove a shard to the system.
renameCollection: no-lock
no help defined
repairDatabase: no-lock
no help defined
replSetGetStatus: no-lock adminOnly slaveOk
Not supported through mongos
resetError: no-lock
no help defined
serverStatus: no-lock
no help defined
setParameter: no-lock adminOnly slaveOk
set administrative option(s)
example:
{ setParameter:1, notablescan:true }
supported so far:
notablescan
logLevel
quiet
shardCollection: no-lock adminOnly slaveOk
Shard a collection. Requires key. Optional unique. Sharding must already be enabled for the database.
{ enablesharding : "<dbname>" }
shutdown: no-lock adminOnly slaveOk
shutdown the database. must be ran against admin db and either (1) ran from localhost or (2) authenticated.
split: no-lock adminOnly slaveOk
example: - split the shard that contains give key
{ split : 'alleyinsider.blog.posts' , find : { ts : 1 } }
example: - split the shard that contains the key with this as the middle
{ split : 'alleyinsider.blog.posts' , middle : { ts : 1 } }
NOTE: this does not move move the chunks, it merely creates a logical seperation
top: read-lock adminOnly slaveOk
usage by collection
validate: no-lock
no help defined
whatsmyuri: no-lock
{whatsmyuri:1}
