Same here, my CPU went to 75°C and my fan ran crazy just by going to that page on my laptop.
I will burst out in joy the day flash is finally abandoned.
Unfortunately this prevented me from checking the content as it's just too annoying.
MongoDB's map reduce is pretty janky, although it's slightly less janky in MongoDB 2.0. I'm not convinced that their home grown m/r is a better option.
They mentioned the "global javascript interpreter lock", which may be slightly inaccurate, but it's true that you can only run one m/r job per mongod instance at a time. It's relatively easy to get around that, though, since you can have replica sets and run jobs on the slave members. You can even have small replica set instances that only do m/r.
There are a couple of other problems, one is that Mongo writes map output into a temporary collection. There's also entirely too much BSON <-> Javascript converting going on. Mongo 2 addresses some of this with the JS Only flag, but it's limited to something like half a million inputs at a time: http://www.mongodb.org/display/DOCS/MapReduce#MapReduce-jsMo...
If I ran into intractable map reduce problems with MongoDB, I'd probably just jump to Riak or something. My guess is that they'll continue to improve things in Mongo land at roughly the same pace as I run into problems, though.
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[ 3.8 ms ] story [ 29.9 ms ] threadUnfortunately this prevented me from checking the content as it's just too annoying.
The video: http://blip.tv/rick-copeland/realtime-analytics-using-mongod...
They mentioned the "global javascript interpreter lock", which may be slightly inaccurate, but it's true that you can only run one m/r job per mongod instance at a time. It's relatively easy to get around that, though, since you can have replica sets and run jobs on the slave members. You can even have small replica set instances that only do m/r.
There are a couple of other problems, one is that Mongo writes map output into a temporary collection. There's also entirely too much BSON <-> Javascript converting going on. Mongo 2 addresses some of this with the JS Only flag, but it's limited to something like half a million inputs at a time: http://www.mongodb.org/display/DOCS/MapReduce#MapReduce-jsMo...
If I ran into intractable map reduce problems with MongoDB, I'd probably just jump to Riak or something. My guess is that they'll continue to improve things in Mongo land at roughly the same pace as I run into problems, though.
- Using V8 instead of spidermonkey [Will probably lead to better performance for MongoDB's map reduce] https://jira.mongodb.org/browse/SERVER-2407
- New aggregation framework [Will make it easy and fast to do simple aggregations] https://jira.mongodb.org/browse/SERVER-447
There is also Hadoop adapter that read and write directly from/to MongoDB that is in an early stage https://github.com/mongodb/mongo-hadoop
@rbranson - if you have thoughts on ways to improve, please do add them to http://jira.mongodb.org :)