Details
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Improvement
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Resolution: Done
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Major - P3
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None
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None
Description
Based on customer interaction, it seems we need a better doc than this one for calculating how much RAM you need for your app:
I think there's some useful verbiage in my responses to CS-4233, and probably scattered all over in a million answers from 10gen staff to questions over the years of the form, "Do I have enough RAM?"
Here are the points I think we should hit:
*) Relationship b/w db storage and working set
*) OS's LRU cache strategy
*) Impact of journaling
*) Using page faults and other MMS gauges to detect when you need more RAM
*) What is non-mapped memory? It's basically a linear function of connection count.
*) The oplog can be ignored when calculating working set (for some reason, that customer thought it was especially important when the opposite is true)