I have a mongoDB collection with 42M registers with 1M new registers every day.
We found a low performance on mongoDB querying. showing in mongostat the fields: qr|qw ar|aw with values of 300-500.
First move was to check index and make new indexes for querys that may took so long.
Now we are getting a good performance most of the time.
But in some cases (random time) we get a lot of connections in pending status, all slow on querys.
But, the top command shows a good performance on processing speed and ram.
The question is:
How I can check more further what are the not optimized querys.
In new relic show the INSERT command in this specific collection take the 62% of "most time consuming", there is any way to speed this up?
And why can be the causes of the pending connections? The strange thing is: when the numbers starts going up never stops until website crash.
We finally solved a big part of the problem doing this steps:
- Move mongo to a new server withouth a openvz, seems mongo gives troubles with openvz
- New filesystem and saas.
- Create new indexes based on our needs.
Mongo is now running pretty well, so thanks all for your help :)