Shulou(Shulou.com)05/31 Report--

Today, I will talk to you about how to set up a sharding cluster in mongodb. Many people may not know much about it. In order to make you understand better, the editor has summarized the following content for you. I hope you can get something according to this article.

1. Enable sharding first, and enable the sharding function of the database

Mongos > use admin

Mongos > db.runCommand ({"enablesharding": "test1"})

2. To slice a specific collection, select the slice key as "_ id"

Mongos > db.runCommand ({"shardcollection": "test1.test1", "key": {"_ id": 1}})

{"collectionsharded": "test1.test1", "ok": 1}

3. Observe the number of shard_01 shard_02 tunks in 2 fragments

# Delete shards #

1. Make sure the equalizer is turned on

Mongos > use admin

Mongos > sh.setBalancerState (true)

Or mongos > sh.startBalancer ()

2. Migrate all the sharded collections to other shards

Use admin

Db.adminCommand ({"removeShard": "shard_name"})

3. Check the status of block migration. The remaining field indicates the number of remaining blocks.

Use admin

Db.runCommand ({removeShard: "shard_name"})

= # Delete unsharded database # =

1. View the database that is not sharded

Use config

Db.databases.find ({$or: [{"partitioned": false}, {"primary": "shard_name"}]})

2. Modify the main shard of the database

Db.runCommand ({movePrimary: "db_name", to: "new_shard"})

= # refresh the configuration cache of mongos # =

Forces mongos to synchronize configuration information from config server and flush the cache

Use admin

Db.adminCommand ({flushRouterConfig: 1})

= oplog to do daily automatic log rotation

1. Add parameters to the configuration file

Logpath=/data/shard_01/mongodb.log

Logappend=true

2. Set scheduled tasks

0 * / bin/kill-SIGUSR1 `cat / data/shard_01/ mongodb.log`

Oplog size can be modified online in mongodb 3.6or later

Use local

Db.adminCommand ({replSetResizeOplog: 1, size: 100000})

After reading the above, do you have any further understanding of how to set up sharding clusters in mongodb? If you want to know more knowledge or related content, please follow the industry information channel, thank you for your support.

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