The document provides an overview of MongoDB administration topics including: - Supported platforms for MongoDB - Common MongoDB administration tools like mongod, mongo, and mongodump - How to set up replication with replica sets for high availability and data redundancy - Popular tools for MongoDB monitoring like munin, ganglia, nagios, and cacti - How to take backups with mongodump or filesystem snapshots - The importance of indexing queries for performance and avoiding table scans

1. Administration
Kevin Hanson
Solutions Architect, 10gen
twitter: @hungarianhc
kevin@10gen.com

2. http://www.mongodb.org/display/DOCS/Admin+Zone

3. Supported Platforms
• OS X
• Linux
• Solaris
• Windows
• FreeBSD

4. The Basics ~ /bin
• mongod: database server
• mongo: shell
• mongos: sharding router
• mongodump: backup tool
• mongostat: monitoring tool

5. Is it working?
• Logs
• Netstat
• Try Out the Shell

6. Starting for Real
• distro packages
• --fork
• --logpath
• --quiet

7. Our Agenda
• Replication
• Monitoring
• Backups
• Queries + Indexes

8. Replication

9. Replication & The Oplog
• Replication: Use It!
• Mind the Oplog Size
• Consider Delayed Replication

10. Replica Sets
• One Primary, Many Secondaries
• High Availability ~ Self Healing
• Strongly Consistent
• Hidden Nodes, Delayed SECONDARIES
• Reading from SECONDARIES
• If the PRIMARY goes down, can the remaining
SECONDARIES handle the load?
• Are You Okay With Less Up to Date Data?
• If the answer to either question is no, stick with
reading from PRIMARIES...

11. Replica Sets
Node 1! Node 2!
Secondary! Heartbeat+ Secondary!
Node 3!
Primary! Replication+
Replication+
• Replication is Asynchronous
• Nodes Can Be in Different Datacenters
• Tailing the Oplog
• Monitor Secondary Delay + Oplog Size

12. A Look at the Oplog

13. Monitoring

14. MongoDB Monitoring Service
• SaaS solution providing instrumentation and
visibility into MongoDB systems
• Free version released
• 5,000+ customers using service
• Installable Version Coming

15. MongoDB Monitoring Service

16. Popular Monitoring Plugins
• munin
• ganglia
• nagios
• cacti

17. Popular Monitoring Plugins
• munin
• ganglia
• nagios
• cacti

18. iostat -x 2

19. mongostat

20. Backups

21. Mongodump
• http://docs.mongodb.org/manual/reference/
mongodump/
• Binary Export
• Best to Run Off Hidden Nodes / Delayed
Secondaries

22. Filesystem Snapshots
• Journaling...
• If turned on, and on the same filesystem,
snapshot at will.
• If not on or mounted somewhere else,
fsync lock required
• Use a filesystem that supports snapshots :-)

23. Queries / Indexes

24. Queries + Indexes

25. Queries + Indexes
• Note the Cursor Type (Btree vs. Basic)
• Most Use-Cases: Queries Should be Indexed
• Force No Table Scans
• --notablescan
• Indexes Should Fit in RAM
• Indexes Slow Writes
• Use them when you need them...
• Don’t use them when you don’t...
• Use the Slow Query Log

26. Viewing / Killing Ops

27. Download MongoDB
http://www.mongodb.org
and let us know what you think
@hungarianhc @mongodb