ESI slowing down page loading

[Dridi Boukelmoune]

Hello Pinakee,

On Tue, Mar 5, 2019 at 8:16 AM Pinakee BIswas <pinakee at waltzz.com> wrote:
>
> Hi,
>
> We are using varnish 4.1.8 and Django 1.11 for our application.
>
> We are using ESI to break down caching on a page. Part of pages which
> are dynamically loaded are fetched from the backend server using ESI but
> if there are multiple ESI calls on a page, the server response time and
> hence, the page loading increases. This is because of the increase in
> the number of calls to the backend server before Varnish serves the page
> to the client.
>
> Could you please let me know if there is a way to optimize the above?

Unfortunately there's little you can do to lower the latency on heavy
ESI misses or passes with Varnish Cache.

Varnish Plus on the other hand has parallel ESI that should bring down
latency to the longest fetch instead of all of them:

https://info.varnish-software.com/blog/varnish-lab-parallel-esi
https://info.varnish-software.com/blog/parallel-versus-serial-esi-processing-benchmarks

Dridi