mongodb学习(-)
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MongoDB 是一个基于分布式文件存储的数据库。由 C++ 语言编写。 旨在为 WEB 应用提供可扩展的高性能数据存储解决方案。 MongoDB 是一个介于关系数据库和非关系数据库之间的产品，是非关系数据库当中功能最丰富，最像关系数据库的。 什么是NoSQL? NoSQL，指的是非关系型的数据库。NoSQL有时也称作Not Only SQL的缩写， 是对不同于传统的关系型数据库的数据库管理系统的统称。 NoSQL用于超大规模数据的存储。（例如谷歌或Facebook每天为他们的用户收集万亿比特的数据）。 这些类型的数据存储不需要固定的模式，无需多余操作就可以横向扩展。 mongodb复制集配置 因为机器比较卡，所以就搭建在一台虚拟机里了,配置复制集，至少需要3个实例 master 192.168.1.156:27017 slave 192.168.1.156:37017 arbiter 192.168.1.156:47017 [[email protected]_all_192.168.1.156 ~]# egrep -v ‘^#|^$‘ /etc/mongodb.conf bind_ip = 192.168.1.156 port = 27017 fork = true pidfilepath = /var/run/mongodb/mongodb.pid logpath = /var/log/mongodb/mongodb.log dbpath =/var/lib/mongodb journal = true replSet = shard1 nohttpinterface = true [[email protected]_all_192.168.1.156 ~]# egrep -v ‘^#|^$‘ /etc/mongodb_37017.conf bind_ip = 192.168.1.156 port = 37017 fork = true pidfilepath = /var/run/mongodb_37017/mongodb.pid logpath = /var/log/mongodb_37017/mongodb.log dbpath =/var/lib/mongodb_37017 journal = true replSet = shard1 nohttpinterface = true [[email protected]_all_192.168.1.156 ~]# egrep -v ‘^#|^$‘ /etc/mongodb_47017.conf bind_ip = 192.168.1.156 port = 47017 fork = true pidfilepath = /var/run/mongodb_47017/mongodb.pid logpath = /var/log/mongodb_47017/mongodb.log dbpath =/var/lib/mongodb_47017 journal = true replSet = shard1 nohttpinterface = true ps aux |grep mongo root 62095 0.6 3.1 3304700 60460 ? Sl 20:07 0:24 mongod --quiet -f /etc/mongodb_57017.conf root 62387 0.6 2.0 2944248 39176 ? Sl 20:08 0:24 mongod --quiet -f /etc/mongodb_47017.conf root 66145 0.6 3.5 5419352 67156 ? Sl 20:20 0:18 mongod --quiet -f /etc/mongodb_37017.conf root 68910 0.6 3.1 5264784 60024 ? Sl 20:25 0:16 mongod --quiet -f /etc/mongodb.conf [[email protected]_all_192.168.1.156 ~]# mongo --host=192.168.1.156 MongoDB shell version: 2.4.14 connecting to: 192.168.1.156:27017/test shard1:PRIMARY> show dbs; local2.0771484375GB test0.203125GB wabao0.203125GB shard1:PRIMARY>rs.conf() { "_id" : "shard1", "version" : 15, "members" : [ { "_id" : 0, "host" : "192.168.1.156:27017", "priority" : 10 }, { "_id" : 1, "host" : "192.168.1.156:37017", "priority" : 5 }, { "_id" : 2, "host" : "192.168.1.156:57017", "priority" : 3 } ] } shard1:PRIMARY>rs.conf() shard1:PRIMARY> help db.help() help on db methods db.mycoll.help() help on collection methods sh.help() sharding helpers rs.help() replica set helpers help admin administrative help help connect connecting to a db help help keys key shortcuts help misc misc things to know help mr mapreduce 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 show logs show the accessible logger names show log [name] prints out the last segment of log in memory, ‘global‘ is default 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 shard1:PRIMARY> db.help() DB methods: db.addUser(userDocument) db.adminCommand(nameOrDocument) - switches to ‘admin‘ db, and runs command [ just calls db.runCommand(...) ] 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 currently executing operations in the db db.dropDatabase() db.eval(func, args) run code server-side db.fsyncLock() flush data to disk and lock server for backups db.fsyncUnlock() unlocks server following a db.fsyncLock() 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 queries on a replication slave server 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.hostInfo() get details about the server‘s host db.isMaster() check replica primary status db.killOp(opid) kills the current operation in the db db.listCommands() lists all the db commands db.loadServerScripts() loads all the scripts in db.system.js db.logout() db.printCollectionStats() db.printReplicationInfo() db.printShardingStatus() db.printSlaveReplicationInfo() 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.setVerboseShell(flag) display extra information in shell output db.shutdownServer() db.stats() db.version() current version of the server shard1:PRIMARY> 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.syncFrom(hostportstr) make a secondary to sync from the given member 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 db.printReplicationInfo() check oplog size and time range 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 shard1:PRIMARY> db.collection.find().help() find() modifiers .sort( {...} ) .limit( n ) .skip( n ) .count() - total # of objects matching query, ignores skip,limit .size() - total # of objects cursor would return, honors skip,limit .explain([verbose]) .hint(...) .addOption(n) - adds op_query options -- see wire protocol ._addSpecial(name, value) - http://dochub.mongodb.org/core/advancedqueries#AdvancedQueries-Metaqueryoperators .batchSize(n) - sets the number of docs to return per getMore .showDiskLoc() - adds a $diskLoc field to each returned object .min(idxDoc) .max(idxDoc) Cursor methods .toArray() - iterates through docs and returns an array of the results .forEach( func ) .map( func ) .hasNext() .next() .objsLeftInBatch() - returns count of docs left in current batch (when exhausted, a new getMore will be issued) .count(applySkipLimit) - runs command at server .itcount() - iterates through documents and counts them shard1:PRIMARY> sh.help() sh.addShard( host ) server:port OR setname/server:port sh.enableSharding(dbname) enables sharding on the database dbname sh.shardCollection(fullName,key,unique) shards the collection sh.splitFind(fullName,find) splits the chunk that find is in at the median sh.splitAt(fullName,middle) splits the chunk that middle is in at middle sh.moveChunk(fullName,find,to) move the chunk where ‘find‘ is to ‘to‘ (name of shard) sh.setBalancerState( <bool on or not> ) turns the balancer on or off true=on, false=off sh.getBalancerState() return true if enabled sh.isBalancerRunning() return true if the balancer has work in progress on any mongos sh.addShardTag(shard,tag) adds the tag to the shard sh.removeShardTag(shard,tag) removes the tag from the shard sh.addTagRange(fullName,min,max,tag) tags the specified range of the given collection sh.status()
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