modifying primary shards
Db.runcommand ({"Moveprimary": "DB", To: "Shard ID"});
2. Merging data blocks (data blocks need to be empty)
Db.runcommand ({"Mergechunks": "Db.collection", Bounds:[min_shardkey,max_shardkey]})
3. Get Data block size
Db.runcommand ({"DataSize": "Db.collection", "Keypattern": {shardkey:1}, Min:{sharkey:min},max:{shardkey:max}})
4. Get the split policy
Db.runcommand ({splitvector: "Db.collection", Keypattern: {sharkey:1}, maxchunksizebytes:10008864})
5. Repairing the database
Db.repairdatabase ()
6. Repairing Collections
Db.collection.runCommand ("compact")
7. Copy the database
Db.copydatabase ("Fromdb", "Todb", "Fromhost")
8. You should back up the configuration server's data before performing a cluster maintenance operation
9. One MONGOs process should be used per application server
10. Edit Slice Key: Export data, modify slice key, then import data
11. Import data before creating indexes more efficiently than creating indexes before importing data
This article is from the architect's path blog, so be sure to keep this source http://lizhuquan0769.blog.51cto.com/2591147/1767618
"MongoDB" common knowledge points