CODEWITHSUNDEEP
mongodbconcurrencymapreduce
h3x3d
h3x3d

Reputation: 231

Mongodb concurrent map reduce

I have collection with events, indexed by time field. Can i run more then one incremental (with output merge to another collection) map-reduce job on it in parallel? (for example - on each five minutes)?

Upvotes: 0

Views: 335

Answers (2)

phyrox
phyrox

Reputation: 2449

Since the MongoDB 2.4 version, the V8 JavaScript engine became the default and it allows multiple JavaScript operations to execute at the same time.

So yes, you can execute several map reduce jobs concurrently in parallel.

Upvotes: 0

Sammaye
Sammaye

Reputation: 43884

The JavaScript engine is single threaded per shard or mongod so even though you could schedule another MR to be run on the same computer I do not believe it will run until the current running MR is completed.

That being said I do think V8 allows for the con-currency features required for your question: http://jira.mongodb.org/browse/SERVER-2407 that is something I think you will want to watch.

Upvotes: 2

Related Questions