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Idea: "Uneviction" :)

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Mon, 01/14/2013 - 08:22
pgrigor
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Hey guys,

I have a cluster which had a bunch of data in it which expired. My *entire* active data should now fit in memory but I'm still getting disk read stats. Why not have the db slurp in data to memory once the low water mark is breached à la when a cluster node is booted?

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Mon, 01/14/2013 - 09:35
tgrall
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Joined: 09/05/2012
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Hello,

I am not sure to understand correctly your request. You want Couchbase to load automatically all the document in memory?

Regards

__________________

Tug
@tgrall

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Mon, 01/14/2013 - 10:06
pgrigor
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Yes, right now when CB hits the high-water mark it starts to "evict" data from memory to disk, however, when the low-water mark is hit CB doesn't load data from disk to memory.

For example: I currently have a test cluster with a total of 6G memory available. Recently I did a big data purge which brought the active document size from 9+G to less than 2G, however CB is hitting the disk most of the time to satisfy document requests. Presently I have around 55% active docs in memory and a *ton* of memory laying around. Of course the 55% is climbing as documents are individually retrieved and put in memory, but why not have CB aggressively load documents from disk to memory in the background when the active document total size is so much less than the low water mark?

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