Re: Conditional caching question
Hi. Sorry for not getting back sooner. The use case I have is have backend determine when frequency reaches a threshold and set ttl dynamically based on the rate. My goal is to tune cache using rates and ttl values to ensure only most requested makes it into the cache as opposed to adding 'bulk'. I am simply experimenting at this stage but believe it can result in a sort of 'smart caching' to maximize the benefit of the cache for content in demand while minimizing the overall cache resource to deliver the resources. I am sure that somewhere here is an algorithm for that can provide some decent cache regulation for utilization and size. Its all a bit of a balancing act with the responsible for the backend as well I realize. Many thanks. Regards David Barry Abrahamson wrote: > On Jun 2, 2008, at 8:41 AM, Poul-Henning Kamp wrote: > >> In message <[EMAIL PROTECTED]>, David Pratt writes: >> >>> Hi. In most cases, I want a request to be passed to a backend where it >>> will be handled by server. If frequency is high, however; I want to add >>> the object to varnish cache and have varnish handle it. I am not worried >>> about a mechanism to keeping track of frequency of requests. Question is >>> what is available to me to add an object/path to the varnish cache if it >>> was originally passed? >> >> I wouldn't say that your way of using varnish is backwards relative >> to the design objectives, but you do come close, since we assumed >> caching by default, and pass as exception, rather than the other >> way around. > > We do this on WordPress.com to avoid filling our caches with > infrequently requested data. The way we handle it is when an object > reaches a certain req/sec threshold, we send a header from the backend > and then have varnish configured to only insert objects into the cache > which contain this custom header. Based on phk's reply, I guess we are > using varnish in a somewhat backwards manner as well, since we assume > pass as the detault, insert as the exception. > > This used to work in 1.0.3. I have started to look into upgrading to > trunk, and it doesn't seem to work so well anymore. It looks like the > first time the URL is requested, if it is passed because it hasn't > reached that threshold and the header hasn't been set, all subsequent > requests are automatically "pass" ed. These show up as "Cache hits for > pass" in varnishstat. Any way around this? > > > -- > Barry Abrahamson | Systems Wrangler | Automattic > Blog: http://barry.wordpress.com > > > > > > > ___ varnish-misc mailing list varnish-misc@projects.linpro.no http://projects.linpro.no/mailman/listinfo/varnish-misc
Re: ESI is generating extraneous output for some clients
On Sun, Jun 8, 2008 at 6:09 PM, Poul-Henning Kamp <[EMAIL PROTECTED]> wrote:
> When processing ESI documents, Varnish will send "chunked" encoding
> and the number lines you see ("26", "19", "15" and "0") are the
> chunked headers, they say (in hex) how many characters follow.
Aha, I didn't know about chunked encoding, and missed the
"Transfer-Encoding" header hint.
Thanks,
--
Adriano
___
varnish-misc mailing list
varnish-misc@projects.linpro.no
http://projects.linpro.no/mailman/listinfo/varnish-misc
Re: ESI is generating extraneous output for some clients
In message <[EMAIL PROTECTED]>, "Adria
no Nagel" writes:
>Hi,
>
>When using ESI (trunk r2652), varnish is adding extraneous characters
>to the output sent to the client, depending on the client being used.
>
>For example, for this html file:
>
>
>
>Teste ESI 8
>
>
>
>
>and this vcl snippet:
>
>} elseif (req.url ~ "^/t(este)?.html$") {
>remove obj.http.Last-Modified;
>esi; /* Do ESI processing */
>set obj.ttl = 1m;
>
>"wget http://localhost/teste.html"; generates this output:
>
>26
>
>
>Teste ESI 8
>
>19
>Sun Jun 8 17:37:43 2008
>
>15
>
>
>
>
>0
When processing ESI documents, Varnish will send "chunked" encoding
and the number lines you see ("26", "19", "15" and "0") are the
chunked headers, they say (in hex) how many characters follow.
So for telnet, the above is absolutely correct, but wget shouldn't
show these lines.
>On the other hand, curl & safari get the expected output, eg
As they obviously handle the chunked encoding correctly.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
[EMAIL PROTECTED] | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
___
varnish-misc mailing list
varnish-misc@projects.linpro.no
http://projects.linpro.no/mailman/listinfo/varnish-misc
ESI is generating extraneous output for some clients
Hi,
When using ESI (trunk r2652), varnish is adding extraneous characters
to the output sent to the client, depending on the client being used.
For example, for this html file:
Teste ESI 8
and this vcl snippet:
} elseif (req.url ~ "^/t(este)?.html$") {
remove obj.http.Last-Modified;
esi; /* Do ESI processing */
set obj.ttl = 1m;
"wget http://localhost/teste.html"; generates this output:
26
Teste ESI 8
19
Sun Jun 8 17:37:43 2008
15
0
telnet generates the same output.
On the other hand, curl & safari get the expected output, eg
$ curl http://localhost/teste.html
Teste ESI 8
Sun Jun 8 17:51:49 2008
Can anyone duplicate this problem?
Thanks,
--
Adriano
___
varnish-misc mailing list
varnish-misc@projects.linpro.no
http://projects.linpro.no/mailman/listinfo/varnish-misc
