Varnish Memory usage increase

Guillaume Quintard guillaume at
Wed Feb 7 12:51:19 UTC 2018

Hi there,

So, varnish memory usage will mostly come from three directions:
- storage, include Transient, so check the g_bytes fields in varnishstat.
Passes and shortlived objects will use Transient, so you can either reduce
those, or limit the Transient storage (unbounded by defaukt).
- thread workspaces, one thread typically uses one workspace, so you can
limit the number of threads, or reduce the workspace size
- memory fragmentation: jemalloc will fragment up to 25%, not much you can
do here.

And no, no way to modify the mmap without restarting varnish.

May I ask how much data you are caching?

Guillaume Quintard

On Wed, Feb 7, 2018 at 1:34 PM, Pinakee BIswas <pinakee at> wrote:

> Hi,
> We have been using varnish since more than a year for our ecommerce site.
> Current version is 4.1.8.
> OS is Linux. RAM is 8GB.
> I am observing that the varnish memory usage is increasing (right now 7%)
> and so is resident memory usage increasing.
> The storage being used is file:
> -s file,/tmp/varnish/,${storage}
> I am not sure about the reason for the increase in varnish memory usage:
>    - Is there a way to limit the varnish memory usage?
>    - How can I diagnose what is consuming memory?
>    - Most of our web pages have maximum 2 days of cache. Also, some of
>    the pages might be least visited.
>    - Is there a way to manipulate varnish mmap (when file storage is
>    used)?
> Would appreciate any help on the above for efficient use of varnish.
> Thanks,
> Pinakee
> _______________________________________________
> varnish-misc mailing list
> varnish-misc at
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