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

What is the method of maintaining documents in mongodb? in view of this problem, this article introduces the corresponding analysis and solutions in detail, hoping to help more partners who want to solve this problem to find a more simple and easy way.

The utilization rate of Mongodb CPU is extremely high and the load is ultra-high.

Problem analysis:

MONGODB has high CPU utilization, database congestion or a large number of slow queries.

Mongostat Analysis:

Mongostat sees that the number of requests is not high, and the occurrence of the library is from the library.

Use db.currentOp () to view:

Db.currentOp () looks up a lot of sessions, so it's troublesome to find it here. We can check the log of MONGODB, and the slow query will print the log to the file.

View the MONGODB log:

If you cannot find the log file for MONGODB, you can use ps-elf | grep mongod to find the configuration file, which will contain the relevant configuration.

The LOGPATH parameter in the configuration file is for the configuration log file.

Use tail-100f / data/mongodb/logs/db.log

This query takes 30 seconds.

This query is based on DATAID and connects to MONGODB to see if there is an index for this condition.

Mongo 127.0.0.1:27017

Use datalog

Db. User_operate_log.getIndexes () to get the index of this collection.

It is found that this collection does not have an index about DATAID, so contact the business person and ask for an index.

Db.user_operate_log.ensureIndex ({"dataId": 1})

After adding the index, all alarms about this server disappear:

MONGODB enables cluster sharding to enable sharding to the library:

Sh.enableSharding ("dbname")

Create an index on the collection where you want to open the shard:

Db.collection_name.createIndex ({_ id: "hashed"})

Since I am creating HASH shards here, I can just create an index of type HASH.

Open the collection fragment:

Sh.shardCollection ("dbname.collection_name", {"_ id": "hashed"})

Verify shards:

Sh.status ()

Disk expansion under MONGODB sharding Cluster

Introduction: because the previous disk space is not planned, the data directory of MONGODB is stored in the root partition. The space of the root partition is small and the IO capacity can not keep up. After adding the disk later, you need to migrate the data to the new disk.

Scheme:

Close the backup node.

Mongo 127.0.0.1:27017

Use admin

Db.shutdownServer ()

Migrate the data directory to the new disk and modify the configuration file to the new disk path. (ps-elf | the path where the parameter file can be obtained by grep mongo)

Mv / data/mongo / data1/mongo

Start the standby node.

Complete the operation of all the standby nodes in turn.

The master library is downgraded to a standby library and services are provided by the master library that has been switched to. Note: there will be subtle interruptions in this process, and business communication will not be affected.

Execute rs.stepDown () after the downgrade command of the main library is connected to the main library

You can migrate the original main database data.

After shutting down the library and restarting, you need to use rs.status () to confirm that the replication set is normal.

When switching between master libraries, you need to pay attention to the normal business and replication sets.

The answer to the question about how mongodb maintains the document is shared here. I hope the above content can be of some help to you. If you still have a lot of doubts to be solved, you can follow the industry information channel to learn more about it.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.