Re: [EXTERNAL] Re: check whether it will be a hit on trafficserver

["Fieck, Brennan" <Br...@comcast.com>]

I think `-IXGET` will cause *curl* to drop the body - ATS still serves it to you. Assuming ATS respects that Cache-Control header, then you should be fine to just send a `HEAD` request if you don't want the body. Although I think for objects that are less than up to (roughly) equal to the average object size, fetching the body will be a negligible additional cost as far as ATS is concerned.

If what you're trying to do is see what's stored in your cache, I shamelessly recommend the buggy-but-useful Superior Cache ANalyzer (SCAN) tool: https://github.com/comcast/superior-cache-analyzer
________________________________________
From: Miles Libbey <ml...@apache.org>
Sent: Wednesday, March 27, 2019 3:10 PM
To: users@trafficserver.apache.org
Subject: [EXTERNAL] Re: check whether it will be a hit on trafficserver

I do:
curl -IXGET -H "Cache-Control: only-if-cached" "https://protect2.fireeye.com/url?k=918b742c9b1bbda4.918b5398-c36456a0d5da6c67&u=http://myurlhere"

The -IXGET makes it do a GET, but, drops the body. The Cache-Control:
only-if-cached request header will have ATS respond with a 200 if the
object is in cache, otherwise you get a 504 if not in cache.

miles


On Wed, Mar 27, 2019 at 11:49 AM Jason Yang <pe...@gmail.com> wrote:
>
> Hi community,
>     Is there anyway to check whether a request will be a hit or miss without having trafficserver serving any content and not going to origin? (I think I can do HEAD, but it goes to origin). Thank you!
>
>
> Best,
> Jason

Re: [EXTERNAL] Re: check whether it will be a hit on trafficserver

[Jason Yang <pe...@gmail.com>]

Hi Bryan, Miles and Brennan, 
    The tool is really useful, I wish I knew it earlier. :) 
    And I think what Miles has proposed is what I need, I want to fetch the response from ATS only when it is cached, if it is not, I go other routes. Thank you very much! 


Jason 


> On Mar 27, 2019, at 17:19, Fieck, Brennan <Br...@comcast.com> wrote:
> 
> I think `-IXGET` will cause *curl* to drop the body - ATS still serves it to you. Assuming ATS respects that Cache-Control header, then you should be fine to just send a `HEAD` request if you don't want the body. Although I think for objects that are less than up to (roughly) equal to the average object size, fetching the body will be a negligible additional cost as far as ATS is concerned.
> 
> If what you're trying to do is see what's stored in your cache, I shamelessly recommend the buggy-but-useful Superior Cache ANalyzer (SCAN) tool: https://github.com/comcast/superior-cache-analyzer
> ________________________________________
> From: Miles Libbey <ml...@apache.org>
> Sent: Wednesday, March 27, 2019 3:10 PM
> To: users@trafficserver.apache.org
> Subject: [EXTERNAL] Re: check whether it will be a hit on trafficserver
> 
> I do:
> curl -IXGET -H "Cache-Control: only-if-cached" "https://protect2.fireeye.com/url?k=918b742c9b1bbda4.918b5398-c36456a0d5da6c67&u=http://myurlhere"
> 
> The -IXGET makes it do a GET, but, drops the body. The Cache-Control:
> only-if-cached request header will have ATS respond with a 200 if the
> object is in cache, otherwise you get a 504 if not in cache.
> 
> miles
> 
> 
> On Wed, Mar 27, 2019 at 11:49 AM Jason Yang <pe...@gmail.com> wrote:
>> 
>> Hi community,
>>    Is there anyway to check whether a request will be a hit or miss without having trafficserver serving any content and not going to origin? (I think I can do HEAD, but it goes to origin). Thank you!
>> 
>> 
>> Best,
>> Jason