背景：
通过上一篇的 MongoDB 分片的原理、搭建、应用 大致了解了MongoDB分片的安装和一些基本的使用情况，现在来说明下如何管理和优化MongoDB分片的使用。
知识点：
1) 分片的配置和查看
① 添加分片：sh.addShard("IP:Port")
mongos> sh.addShard("192.168.200.A:40000") #添加分片 { "shardAdded" : "shard0000", "ok" : 1 } mongos> sh.addShard("192.168.200.B:40000") #添加分片 { "shardAdded" : "shard0001", "ok" : 1 } mongos> sh.addShard("192.168.200.C:40000") #添加分片 { "shardAdded" : "shard0002", "ok" : 1 }
② 开启分片功能：sh.enableSharding("库名")、sh.shardCollection("库名.集合名",{"key":1})
mongos> sh.enableSharding("dba") { "ok" : 1 } mongos> sh.shardCollection("dba.account",{"name":1}) { "collectionsharded" : "dba.account", "ok" : 1 }
③ 查看分片状态：sh.status()
mongos> sh.status() --- Sharding Status ---... shards: { "_id" : "shard0000", "host" : "192.168.200.A:40000" } { "_id" : "shard0001", "host" : "192.168.200.B:40000" } { "_id" : "shard0002", "host" : "192.168.200.C:40000" } ... databases: #库 { "_id" : "admin", "partitioned" : false, "primary" : "config" } { "_id" : "test", "partitioned" : false, "primary" : "shard0000" } { "_id" : "dba", "partitioned" : true, "primary" : "shard0000" } #允许分片 dba.account #dba下的分片集合 shard key: { "name" : 1 } chunks: #块信息 shard0000 1 { "name" : { "$minKey" : 1 } } -->> { "name" : { "$maxKey" : 1 } } on : shard0000 Timestamp(1, 0) #块里数据的范围
2) 配置信息说明，config库的介绍。
① 分片信息：config.shards
mongos> db.shards.find() { "_id" : "shard0000", "host" : "192.168.200.51:40000" } { "_id" : "shard0001", "host" : "192.168.200.52:40000" } { "_id" : "shard0002", "host" : "192.168.200.53:40000" } { "_id" : "mablevi", "host" : "mablevi/192.168.200.53:50000,192.168.200.53:50001,192.168.200.53:50002" } #副本级分片，不需要把所有的节点写出
② 分片中所有数据库信息：config.databases
mongos> db.databases.find() { "_id" : "admin", "partitioned" : false, "primary" : "config" } { "_id" : "test", "partitioned" : false, "primary" : "shard0001" } { "_id" : "dba", "partitioned" : true, "primary" : "shard0000" } #分片 { "_id" : "abc", "partitioned" : true, "primary" : "shard0000" } #分片
③ 分片集合信息：config.collections
mongos> db.collections.findOne() { "_id" : "dba.account", "lastmod" : ISODate("2015-07-14T15:12:29.706Z"), "dropped" : false, "key" : { #片键 "name" : 1 }, "unique" : false, #片键是否唯一 "lastmodEpoch" : ObjectId("55a526dd511d36716224fb77") }
④ mongos路由的信息：config.mongs 。可以查看所有mongos的状态
mongos> db.mongos.findOne() { "_id" : "mongo2:30000", "ping" : ISODate("2015-07-27T03:13:06.178Z"), "up" : 323671, #活着时间 "waiting" : true, "mongoVersion" : "3.0.4" #版本 }
⑤ 均衡器锁的信息：config.locks，记录所有集群范围的锁，可得知哪个mongos是均衡器。
mongos> db.locks.findOne() { "_id" : "balancer", #均衡器 "state" : 1, #0非活动状态、1尝试得到锁，但还没得到，2表示正在进行均衡 "who" : "mongo1:30000:1436888525:1804289383:Balancer:846930886", #哪个mongos当均衡器 "ts" : ObjectId("55b5a2d5fdd9a605a039f951"), "process" : "mongo1:30000:1436888525:1804289383", "when" : ISODate("2015-07-27T03:17:41.159Z"), "why" : "doing balance round" #均衡导致锁 }
⑥ 记录所有块的信息：config.chunks，也可以通过sh.status()查看
mongos> db.chunks.find().pretty() { "_id" : "dba.account-name_MinKey", #标识符 "lastmod" : Timestamp(2, 0), #块的版本 "lastmodEpoch" : ObjectId("55a526dd511d36716224fb77"), #块的版本 "ns" : "dba.account", #集合名 "min" : { #数据范围 "name" : { "$minKey" : 1 } }, "max" : { "name" : "9XXqCaBhfhPIXLq" }, "shard" : "mablevi" #所在分片 } { "_id" : "dba.account-name_\"9XXqCaBhfhPIXLq\"", "lastmod" : Timestamp(4, 0), "lastmodEpoch" : ObjectId("55a526dd511d36716224fb77"), "ns" : "dba.account", "min" : { "name" : "9XXqCaBhfhPIXLq" }, "max" : { "name" : "RWINvgjYYQmbZds" }, "shard" : "shard0002" }
⑦ 记录所有的分片操作：config.changelog，拆分、迁移
拆分：
{ "_id" : "mongo1-2015-07-14T15:12:40-55a526e8f0432675a473009c", "server" : "mongo1", "clientAddr" : "192.168.200.52:53257", "time" : ISODate("2015-07-14T15:12:40.375Z"), "what" : "multi-split", #拆分 "ns" : "dba.account", "details" : { #拆分先后的信息 "before" : { "min" : { #拆分前范围 "name" : { "$minKey" : 1 } }, "max" : { "name" : { "$maxKey" : 1 } } }, "number" : 1, #第一个块 "of" : 3, #拆分成3个块 "chunk" : { "min" : { "name" : { "$minKey" : 1 } }, "max" : { "name" : "9XXqCaBhfhPIXLq" }, "lastmod" : Timestamp(1, 1), #版本号 "lastmodEpoch" : ObjectId("55a526dd511d36716224fb77") } } } { "_id" : "mongo1-2015-07-14T15:12:40-55a526e8f0432675a473009d", "server" : "mongo1", "clientAddr" : "192.168.200.52:53257", "time" : ISODate("2015-07-14T15:12:40.378Z"), "what" : "multi-split", "ns" : "dba.account", "details" : { "before" : { "min" : { "name" : { "$minKey" : 1 } }, "max" : { "name" : { "$maxKey" : 1 } } }, "number" : 2, "of" : 3, "chunk" : { "min" : { "name" : "9XXqCaBhfhPIXLq" }, "max" : { "name" : "okmjUUZuuKgftDC" }, "lastmod" : Timestamp(1, 2), #版本号 "lastmodEpoch" : ObjectId("55a526dd511d36716224fb77") } } } { "_id" : "mongo1-2015-07-14T15:12:40-55a526e8f0432675a473009e", "server" : "mongo1", "clientAddr" : "192.168.200.52:53257", "time" : ISODate("2015-07-14T15:12:40.381Z"), "what" : "multi-split", "ns" : "dba.account", "details" : { "before" : { "min" : { "name" : { "$minKey" : 1 } }, "max" : { "name" : { "$maxKey" : 1 } } }, "number" : 3, "of" : 3, "chunk" : { "min" : { "name" : "okmjUUZuuKgftDC" }, "max" : { "name" : { "$maxKey" : 1 } }, "lastmod" : Timestamp(1, 3), #版本号 "lastmodEpoch" : ObjectId("55a526dd511d36716224fb77") } } }
迁移：4个文档
{ "_id" : "mongo1-2015-07-14T15:12:41-55a526e9f0432675a47300a1", "server" : "mongo1", "clientAddr" : "192.168.200.52:53257", "time" : ISODate("2015-07-14T15:12:41.406Z"), "what" : "moveChunk.start", #迁移开始 "ns" : "dba.account", "details" : { "min" : { "name" : { "$minKey" : 1 } }, "max" : { "name" : "9XXqCaBhfhPIXLq" }, "from" : "shard0000", "to" : "mablevi" } } { "_id" : "mongo3-2015-07-14T15:12:42-55a526ead5bee637c12aadd4", "server" : "mongo3", "clientAddr" : ":27017", "time" : ISODate("2015-07-14T15:12:42.419Z"), "what" : "moveChunk.to", #from分片 "ns" : "dba.account", "details" : { "min" : { "name" : { "$minKey" : 1 } }, "max" : { "name" : "9XXqCaBhfhPIXLq" }, "step 1 of 5" : 327, #耗时，单位毫秒。检查命令参数 "step 2 of 5" : 301, #申请分布锁 "step 3 of 5" : 1, #连接到to分片 "step 4 of 5" : 0, #数据复制，每个分片都是直接和另一个分片、配置服务器直接连接 "step 5 of 5" : 407, #和to分片、配置服务器确认是否完成 "note" : "success" } } { "_id" : "mongo1-2015-07-14T15:12:42-55a526eaf0432675a47300a2", "server" : "mongo1", "clientAddr" : "192.168.200.52:53257", "time" : ISODate("2015-07-14T15:12:42.854Z"), "what" : "moveChunk.commit", #提交 "ns" : "dba.account", "details" : { "min" : { "name" : { "$minKey" : 1 } }, "max" : { "name" : "9XXqCaBhfhPIXLq" }, "from" : "shard0000", "to" : "mablevi", "cloned" : NumberLong(1), "clonedBytes" : NumberLong(94), "catchup" : NumberLong(0), "steady" : NumberLong(0) } } { "_id" : "mongo1-2015-07-14T15:12:43-55a526ebf0432675a47300a3", "server" : "mongo1", "clientAddr" : "192.168.200.52:53257", "time" : ISODate("2015-07-14T15:12:43.258Z"), "what" : "moveChunk.from", #to分片 "ns" : "dba.account", "details" : { "min" : { "name" : { "$minKey" : 1 } }, "max" : { "name" : "9XXqCaBhfhPIXLq" }, #步骤的时间为毫秒 "step 1 of 6" : 0, #迁移索引 "step 2 of 6" : 613, #删除块内的数据，清理数据残余 "step 3 of 6" : 2, #文档复制到to分片 "step 4 of 6" : 1029, #复制期间，在to分片上执行操作 "step 5 of 6" : 415, #等待to分片将新迁移过来的数据复制到集群 "step 6 of 6" : 0, #修改元数据完成迁移 "to" : "mablevi", "from" : "shard0000", "note" : "success" } }
⑧ 分片标签：config.tags，sh.addShardTag
mongos> db.tags.findOne() { "_id" : { "ns" : "abc.number", "min" : { "num" : 0 } }, "ns" : "abc.number", "min" : { "num" : 0 }, "max" : { "num" : 20 }, "tag" : "AAA" }
⑨ 分片设置：config.settings，设置分片块的大小和开启关闭均衡器
mongos> db.settings.find() { "_id" : "chunksize", "value" : 32 } { "_id" : "balancer", "stopped" : false }
⑩ 网络连接数： db.adminCommand({"connPoolStats":1})
mongos> db.adminCommand({"connPoolStats":1})
{
"hosts" : {
"192.168.200.51:20000::0" : {
"available" : 1,
"created" : 1
},
"192.168.200.51:20000::30" : {
"available" : 1,
"created" : 1
},
"192.168.200.51:20000,192.168.200.51:21000,192.168.200.51:22000::0" : {
"available" : 1,
"created" : 1
},
"192.168.200.51:20000,192.168.200.51:21000,192.168.200.51:22000::30" : {
"available" : 3,
"created" : 422
},
"192.168.200.51:21000::0" : {
"available" : 1,
"created" : 1
},
"192.168.200.51:21000::30" : {
"available" : 1,
"created" : 1
},
"192.168.200.51:22000::0" : {
"available" : 1,
"created" : 1
},
"192.168.200.51:22000::30" : {
"available" : 1,
"created" : 1
},
"192.168.200.51:40000::0" : {
"available" : 2,
"created" : 2
},
"192.168.200.52:40000::0" : {
"available" : 1,
"created" : 4
},
"192.168.200.53:40000::0" : {
"available" : 1,
"created" : 2
},
"192.168.200.53:50000::5" : {
"available" : 1,
"created" : 2
},
"192.168.200.53:50001::0" : {
"available" : 1,
"created" : 1
},
"192.168.200.53:50001::5" : {
"available" : 1,
"created" : 2
},
"192.168.200.53:50002::0" : {
"available" : 1,
"created" : 1
},
"192.168.200.53:50002::5" : {
"available" : 1,
"created" : 2
},
"mablevi/192.168.200.53:50000,192.168.200.53:50001,192.168.200.53:50002::0" : {
"available" : 2,
"created" : 3
}
},
"replicaSets" : {
"mablevi" : {
"hosts" : [
{
"addr" : "192.168.200.53:50000",
"ok" : true,
"ismaster" : true,
"hidden" : false,
"secondary" : false,
"pingTimeMillis" : 1
},
{
"addr" : "192.168.200.53:50001",
"ok" : true,
"ismaster" : false,
"hidden" : false,
"secondary" : true,
"pingTimeMillis" : 1
},
{
"addr" : "192.168.200.53:50002",
"ok" : true,
"ismaster" : false,
"hidden" : false,
"secondary" : true,
"pingTimeMillis" : 1
}
]
}
},
"createdByType" : {
"master" : 22,
"set" : 3,
"sync" : 423
},
"totalAvailable" : 21, #总的可用连接
"totalCreated" : 448, #总创建的连接
"numDBClientConnection" : 40,
"numAScopedConnection" : 1,
"ok" : 1
}