Re: SMP cache manager URLs

From: Amos Jeffries <squid3_at_treenet.co.nz>
Date: Thu, 08 Jul 2010 18:17:40 +1200

Alex Rousskov wrote:
> On 07/07/2010 04:41 PM, Amos Jeffries wrote:
>> On Wed, 07 Jul 2010 13:28:50 -0600, Alex Rousskov
>> <rousskov_at_measurement-factory.com> wrote:
>>> Hello,
>>>
>>> We currently use mgr:info and similar URLs to access "cache manager"
>>> interface. I know there are plans to change the protocol and/or domain
>>> name of those URLs, but I want to focus on the URL path (a.k.a. action)
>>> and SMP. We have several options here:
>>>
>>> 1. Keep paths/actions as they are now. Hide individual process state and
>>> report totals from Squid "as a whole" point of view instead.
>>>
>>> 2. Keep paths/actions as they are now. Report individual process state
>>> and also report totals from Squid "as a whole" point of view, all in one
>>> response, with appropriate separators to mark per-process and aggregate
>>> parts.
>>>
>>> 3. Allow action parameters to specify which process(es) state should be
>>> reported. If no parameters were given, just report aggregates. For
>>> example, mgr:info?process_number=2 will trigger the "info" action for
>>> forked process #2.
>>>
>>>
>>> We will have #2 supported soon, but since there are many management
>>> scripts that rely on mgr:info and other actions output format, I think
>>> #2 will not work as a long-term default. Thus, it seems like our choice
>>> is between #1 (simple) and #3 (provides per-process information).
>>>
>>> I cannot promise #3 support soon, but do you think it is needed at all?
>>> Any other long-term options/ideas?
>> I'm for #3 as a long-term. But would prefer a path field instead of a
>> query parameter.
>> ie. mgr:info/2
>
> Why path? Path implies hierarchy so it does not adapt well to future

Which is exactly how I see the use of this field.
  api/general-page/specific-instance/something-else

<scheme>://squid.hostname.local/squid-internal-cachemgr/cachemgr-page-name/instance-to-query/...

The order can even be reversed:
 
<scheme>://squid.local/squid-internal-cachemgr/[instance-to-query/]cachemgr-page-name

> uses (different cache manager parameters for SMP-related or unrelated
> purposes). Is there a problem with CGI-style parameters that you want to
> avoid?

Just a small amount of complexity in the parser an cachemgr generation.

In the end it is your implementation, so this is just my opinion.

Amos

-- 
Please be using
   Current Stable Squid 2.7.STABLE9 or 3.1.5
Received on Thu Jul 08 2010 - 06:17:46 MDT

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