MongoDB Management Service (MMS)OverviewAngshuman Bagchi (angshuman.bagchi@mongodb.com)Technical Services Engineer

Agenda

• What is MMS?– Monitoring

• Why use MMS Monitoring?• Setting it up and getting around• Performance and monitoring

– Backup• Risks• Backup strategies

• Wrap up

What is MMS Monitoring?

Demo

What’s in it for me?

• Great high level view + detailed metrics• Low effort, high-return• Makes it easier for us to help you!

How do I use this crazy thing?

http://mms.mongodb.com/help/monitoring/tutorial/

Performance tuningand monitoring

Pro-Tip: know thyself

You have to recognize normal to know when it isn’t.

Source: http://www.flickr.com/photos/skippy/6853920/

Finding the bottleneck

Source: http://www.flickr.com/photos/laenulfean/462715479/

Some handy metrics to watch

• Memory usage• Opcounters• Lock %• Queues• Background flush average• Replication stats

Example: replication lag

150,000s of lag ~ almost 2 days of lag!

Example: replication lag

• Secondaries under specified vs primaries• Access patterns between primary /

secondaries• Insufficient bandwidth• Foreground index builds on secondaries

“…when you have eliminated the impossible, whatever remains, however improbable, must be the truth…” -- Sherlock Holmes

Sir Arthur Conan Doyle, The Sign of the Four

Example: replication lag

Example:• ~1500 ops per minute (opcounters)• 0.1 MB per object (average object size,

local db)

~1500 ops/min / 60 seconds * 0.1 MB/op * 8b/B =~ 20 mbps required bandwidth

MMS Backup

Disaster do happen … ... sometimes they are our fault

Availability & Durability

risks

[

{

"failure" : [

"storage",

"power",

"host",

"dataCenter"

]

},

"programmerError",

"cyberAttack"

]

• Relative to any particular risk

source:http://www.definethecloud.net/

• Solutions

– Replication– Backup

Addressing Risks

Replication

… but programmer errors … …

garbage in => garbage out

• Much slower to restore (availability suffers)• Out of date to some extent• Fairly cheap• Well isolated• Handles almost all risks

Backup

• mongodump/mongorestore• Storage-level options• MongoDB Backup Service (new!)

Backup Approaches

• Can be run in live or offline mode• Oplog-aware for point-in-time operations• Filter can be applied in both directions• Considerations

– Working set– Sharding

mongodump / mongorestore

• Copy files in your data directory (e.g. /data/db)

• Filesystem or block storage snapshot• Fastest way to backup/restore• Considerations

– Consistency– Backup granularity– Ops expertise

Storage-level Backups

MMS Backup : Overview

Mongodump File system MMS Backup

Initial complexity

Time to restore

Point in time recovery of replica set

System Overhead

Scalable

Consistent Snapshot of Sharded System

Recovery Approaches

How much does it cost?

• Free Tier - monthly bill under $5 is free for first 12 months

Summary

• MMS Monitoring is a great, free service• Setup is easy• Proactively monitor your cluster• MMS Backups makes backing up data

easy• Making MongoDB operations as easy as

development using MongoDB