<span>mongodb分片集群管理</span>
config数据库中的集合：
mongos> show dbs admin 0.000GB athena 157.194GB config 0.014GB
############################# mongos> use config switched to db config
################################## mongos> show tables actionlog changelog chunks collections databases lockpings locks migrations mongos shards system.profile tags transactions version
查看数据库的默认存储分片（主分片）和支持分片的数据库：
这个primary与replica set里面的primary不是一回事，这里的primary是primary shard的意思，我们知道即使在sharded cluster环境中，一些数据量比较小的db也是无需分片的，这些db默认就存放在primary shard上面。
mongos> use config mongos> db.databases.find() { "_id" : "athena", "primary" : "bwactivity_shard", "partitioned" : true, "version" : { "uuid" : UUID("d3c927c5-29ee-4d27-b8ad-ac69332d3059"), "lastMod" : 1 } } mongos> db.databases.find().pretty() { "_id" : "athena", "primary" : "bwactivity_shard", "partitioned" : true, "version" : { "uuid" : UUID("d3c927c5-29ee-4d27-b8ad-ac69332d3059"), "lastMod" : 1 } }
查看分片集群中哪些集合开启了分片和片键：
mongos> db.collections.find().pretty() { "_id" : "config.system.sessions", "lastmodEpoch" : ObjectId("5f89496f82b8dec4f83d5506"), "lastmod" : ISODate("1970-02-19T17:02:47.296Z"), "dropped" : false, "key" : { "_id" : 1 }, "unique" : false, "uuid" : UUID("48dfd0fb-7fcd-44dd-bb26-55e09050d60c") } { "_id" : "athena.athena_user_task_new", "lastmodEpoch" : ObjectId("5f8e4c9382b8dec4f808aefb"), "lastmod" : ISODate("1970-02-19T17:02:47.299Z"), "dropped" : false, "key" : { "uid" : "hashed" }, "unique" : false, "uuid" : UUID("a6bae3e6-4428-4f61-b7a8-30d7a99628e9") } { "_id" : "athena.athena_user_task_v2", "lastmodEpoch" : ObjectId("5fa4e12582b8dec4f8802392"), "lastmod" : ISODate("1970-02-19T17:02:47.299Z"), "dropped" : false, "key" : { "uid" : "hashed" }, "unique" : false, "uuid" : UUID("d1c674ab-3194-4944-8b49-48e0cd511ea3") } { "_id" : "athena.athena_user_task_v3", "lastmodEpoch" : ObjectId("000000000000000000000000"), "lastmod" : ISODate("2020-11-05T06:55:12.147Z"), "dropped" : true } mongos>
查看分片集群中有哪些分片sharding：
mongos> use config
mongos> db.shards.find().pretty() { "_id" : "bwactivity_shard", "host" : "bwactivity_shard/aaa:28001,bbb:28001,ccc:28001", "state" : 1 } { "_id" : "bwactivity_shard2", "host" : "bwactivity_shard2/xxx:28002,yyy:28002,zzz:28002", "state" : 1 }
查看分片集群有哪些路由mongos：
mongos> db.mongos.find().pretty() { "_id" : "ddd:30000", "advisoryHostFQDNs" : [ "c4-internet3-bwaward-mgdb01.bj" ], "mongoVersion" : "4.0.14-8", "ping" : ISODate("2020-11-11T08:20:27.119Z"), "up" : NumberLong(541006), "waiting" : true } { "_id" : "eee:30000", "advisoryHostFQDNs" : [ "c4-internet3-bwaward-mgdb02.bj" ], "mongoVersion" : "4.0.14-8", "ping" : ISODate("2020-11-11T08:20:27.121Z"), "up" : NumberLong(541113), "waiting" : true } { "_id" : "fff:30000", "advisoryHostFQDNs" : [ "c4-internet3-bwaward-mgdb03.bj" ], "mongoVersion" : "4.0.14-8", "ping" : ISODate("2020-11-11T08:20:35.613Z"), "up" : NumberLong(541052), "waiting" : true } mongos>
查看分片集群的分片信息汇总：
mongos> sh.status() --- Sharding Status --- sharding version: { "_id" : 1, "minCompatibleVersion" : 5, "currentVersion" : 6, "clusterId" : ObjectId("5f893d07fe296990bc8a1f50") } shards: { "_id" : "bwactivity_shard", "host" : "bwactivity_shard/aaa:28001,bbb:28001,ccc:28001", "state" : 1 } { "_id" : "bwactivity_shard2", "host" : "bwactivity_shard2/xxx:28002,yyy:28002,zzz:28002", "state" : 1 } active mongoses: "4.0.14-8" : 3 autosplit: Currently enabled: yes balancer: Currently enabled: yes Currently running: no Failed balancer rounds in last 5 attempts: 0 Migration Results for the last 24 hours: 41 : Success 1 : Failed with error 'aborted', from bwactivity_shard to bwactivity_shard2 databases: { "_id" : "athena", "primary" : "bwactivity_shard", "partitioned" : true, "version" : { "uuid" : UUID("d3c927c5-29ee-4d27-b8ad-ac69332d3059"), "lastMod" : 1 } } athena.athena_user_task_new shard key: { "uid" : "hashed" } unique: false balancing: true chunks: bwactivity_shard 295 bwactivity_shard2 294 too many chunks to print, use verbose if you want to force print athena.athena_user_task_v2 shard key: { "uid" : "hashed" } unique: false balancing: true chunks: bwactivity_shard 1332 bwactivity_shard2 1335 too many chunks to print, use verbose if you want to force print { "_id" : "config", "primary" : "config", "partitioned" : true } config.system.sessions shard key: { "_id" : 1 } unique: false balancing: true chunks: bwactivity_shard 1 { "_id" : { "$minKey" : 1 } } -->> { "_id" : { "$maxKey" : 1 } } on : bwactivity_shard Timestamp(1, 0) mongos>
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