MongoDB: How it Works

@mongodb @mdirolf http://www.mongodb.org/

How it Works http://www.ﬂickr.com/photos/tmh9/677919415/

BSON {“hello”: “bson”} x15 x00 x00 x00 x02 h e l l o x00 x05 x00 x00 x00 b s o n x00 x00 http://bsonspec.org

Messages • TCP/IP Wire Protocol • Separate messages for insert, update, query, get_more, delete, etc. http://www.mongodb.org/display/DOCS/Mongo+Wire+Protocol

Anatomy of an insert use foo; db.test.insert({“hello”: “bson”}); message length request id response id op code (insert) x67x00x00x0 xXXxXXxXX x00x00x00x xd2x07x00x00 0 xXX 00 reserved collection name document(s) x00x00x00x00 f o o . t e s t x00 BSON({“hello”: “bson”}) http://www.mongodb.org/display/DOCS/Mongo+Wire+Protocol

Memory mapped storage engine

Commands db.foo.drop(); = db.foo.runCommand({drop: "foo"}); = db.$cmd.ﬁndOne({drop: "foo"}); = db.$cmd.ﬁnd({drop: "foo"}).limit(-1);

Query optimizer ﬁnd({x: 10, y: “foo”}) scan terminate index on x index on y remember

Geohashing (20, 10) (0001 0100, 0000 1010) 0000 0010 0110 0100 (21, 9) 0000 0010 0110 0011 Problem: bit-ﬂips (127 vs 128)

Replication Replica sets Master - slave master slave master master slave slave slave slave master master slave slave master

Replication • oplog - capped collection • idempotent ($inc -> $set)

Auto-sharding Shards mongod mongod mongod ... Conﬁg mongod mongod mongod Servers mongod mongod mongod mongos mongos ... client

MongoDB: How it Works

by Mike Dirolf

Accessibility

Categories

Upload Details

Usage Rights

1 Embed 21

Statistics

MongoDB: How it Works Presentation Transcript