Processing ESIs in parallel

Steve Webster steve.webster at
Fri Mar 4 13:39:25 CET 2011

On 4 Mar 2011, at 11:07, Poul-Henning Kamp wrote:

> In message <FC1F5965-7DAC-4D30-8A4E-33B81E917C9B at>, Steve Webster w
> rites:
>> I know there has been a lot of work on ESIs for Varnish 3, but as far as I 
>> can tell they are still processed serially. Are there any plans to switch to
>> a parallel processing model? If not, might this be a worthy feature request
>> for a future version of Varnish?s
> I wouldn't call them "plans", but it is on our wish-list.

This is good news.

> It is not simple though, so don't hold your breath.

Indeed. I had one of those "how hard could this be" moments and started trying to implement it myself, then realised I had opened a can of worms and decided to leave Varnish hacking to the experts.

I have a workaround for now – a custom Apache output filter that uses LWP::Parallel – so thankfully breathe-holding isn't necessary.



Steve Webster
Web Architect

LOVEFiLM UK Limited is a company registered in England and Wales. 
Registered Number: 06528297. 
Registered Office: No.9, 6 Portal Way, London W3 6RU, United Kingdom.

This e-mail is confidential to the ordinary user of the e-mail address to which it was addressed. If you have received it in error, 
please delete it from your system and notify the sender immediately.

This email message has been delivered safely and archived online by Mimecast.
For more information please visit 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the varnish-misc mailing list