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What is this "Other Data" in memory used section?

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Thu, 01/05/2012 - 12:59
enkrypt3d
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Under Manage > Server Nodes > click one server it shows about 9GB of memory used for membase (Blue line) and an orange line that says "other data"......

 

Does anyone know what this is? My memory usage says its at 99.3% but its really not "USED" memory..... the server itself shows: Mem: 32961872k total, 32721264k used, 240608k free, 599596k buffers Membase is the only service running on this host.....

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Tue, 01/17/2012 - 14:19
enkrypt3d
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Bumping this thread.... is this a concern? Why are there so many unanswered threads? SMH.........

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Wed, 02/01/2012 - 18:10
ingenthr
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I just read through the code, and from my read it may be pulling from the wrong statistic. I am not very confident of that though, so I'm going to get some help looking into it.

That'll be on the issue tracked here:
http://www.couchbase.com/issues/browse/MB-4747

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Wed, 02/01/2012 - 18:41
alkondratenko
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Well we seem to be adding page cache memory to "other". And that's not necessarily wrong thing to do. As you can see your server has only 240 megs free. Which seem to match what the graph has.

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Wed, 02/01/2012 - 18:42
enkrypt3d
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alkondratenko wrote:
Well we seem to be adding page cache memory to "other". And that's not necessarily wrong thing to do. As you can see your server has only 240 megs free. Which seem to match what the graph has.

are we talking about buffered / cached memory within the linux OS? If so then yea its nothing to worry about... but it shows up as 99% used in the servers list... not really accurate if its not 99% used by membase.

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Wed, 02/01/2012 - 18:50
alkondratenko
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Yes it's about memory used for caching things. And memory used by membase is blue part of bar. This screen is supposed to give you about state of particular server and membase use of this server resource in that context.

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Wed, 02/01/2012 - 19:42
enkrypt3d
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alkondratenko wrote:
Yes it's about memory used for caching things. And memory used by membase is blue part of bar. This screen is supposed to give you about state of particular server and membase use of this server resource in that context.

yes i know what the blue bar is ...... it shouldn't say that the host is 99% used if its not really used. Linux does buffering and caching within the operating system so as an application begins to use more memory it allows it to expand its memory usage. So saying there isn't any more memory allowed to be used isn't accurate, hence the original intent for this topic.

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Wed, 02/01/2012 - 19:59
alkondratenko
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It never said there are no memory left to be used. And page cache is a quite complex thing. You can only really free clean pages. And it's not impossible to create lots of dirty once. In which case freeing them requires writing them down first.

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Wed, 02/01/2012 - 22:18
enkrypt3d
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alkondratenko wrote:
It never said there are no memory left to be used. And page cache is a quite complex thing. You can only really free clean pages. And it's not impossible to create lots of dirty once. In which case freeing them requires writing them down first.

Ok so under Monitor > server nodes > it shows 99.4% ram usage... even though the cluster overview shows only 52GB out of 128GB used for membase..

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