On Jul 21, 1:41 pm, Trond Norbye <[email protected]> wrote:
> Are you running out of virtual memory ;)
>

Well, the problem is that memcached will use swap, when it runs out of
resident memory.  When swap space fills up, memcached will crash under
load.

Yesterday, I had the -m option set to 3700 (or 3700 megabtyes), since
I have a 4GB system.  But, I started getting evictions when the
dataset reached the size of 3219.9 megabytes.  As I mentioned above, I
started getting evictions at 3763 megabytes of RSS and 3834 megabytes
of VSZ.  Is the -m option the size of the dataset or is it the size of
resident memory?

Today, I increased the -m option to 8000 (or 8000 megabytes) to see
what would happen.  I only have 3954 megabytes total memory in the
system.  Now, memcached is filling up the swap space.  I assume that I
will start getting evictions when the virtual memory is full.

It seems to me that I should avoid touching the swap space, since
memcached can become unstable when using swap space.  But, last week,
I got into trouble because I set the -m option close to the total
available memory on the system, and I guess that I had the value set
too high, since the swap space filled up and memcached crashed.
Today, I am trying to duplicate the issue that I saw last week.

David

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