Re: [squid-users] Jobs

From: Amos Jeffries <squid3_at_treenet.co.nz>
Date: Wed, 29 Jun 2011 02:32:37 +1200

On 29/06/11 01:37, Mohsen Pahlevanzadeh wrote:
> On Tue, 2011-06-28 at 06:01 -0700, John Doe wrote:
>> From: Mohsen Pahlevanzadeh<mohsen_at_pahlevanzadeh.org>
>>
>>>>> We must write a program that along with normal tasks, it had do a
>>>>> variety of jobs,But i need to PURGE and insert cache.
>>> I must a write a web appl thet it manages squid with many extra job.
>>> normal job: every work that squid can do.
>>> Variety of job: a range of task that my boss ordered.
>>
>> Amos question: What are these "normal tasks" and "variety of jobs"?
>> Your answer: extra job, normal job, a variety of job, a range of tasks...
>> Which does not answer the question at all...
>> Can you name the main tasks/jobs you need to do?
>> By example: start/stop/restart/reload squid, reset cache, purge/cache url?
>> Graph statistics, etc...
>> I believe that for most of these, you do not need to play with the squid code...
>>
>> JD
> 1. PURGE from my program, but i can't call squidclient PURGE -m
> "blahblah" from my code.

Sure you can. Several prefetchers just run exec("squidclient blah")

But now that it is clear you are building a whole management app, not
just a prefetcher an HTTP library would probably be the better way to
go. libcurl or whatever the equivalent is for your chosen language.

> 2.Insert into cache.

HTTP GET request. Tricky. Since you will have to figure out whether the
clients will be asking for plain or compressed copies.

By far and away the best way to do this is simply not to bother doing it
at all. Squid is designed to do the work of figuring out where objects
are and how to get them to the client fastest.

Inserting objects into the cache may _seem_ to be a good idea. But HTTP
is very complicated and there is a very good chance you will push the
wrong variants of each object into the cache.

> 3.concurrent receive of site(minimum 100 sites)

If by "site" you mean website. Squid is used by ISP. They have
accessible site numbers ranging in the high millions or billions. These
are all concurrently available to an ISP situation, so safe bet on that
requirement.

If by "site" you mean visitor. One Squid routinely handles hundreds or
thousands of clients depending on your hardware specs. Or it may
overload the network on _one_ client requesting TB sized objects.

You need to figure out a request/time-unit metric or a concurrent
connections metric and test that is achievable with the desired
configuration. The squid config file is a mix between simple
on/off/value settings and a big script which tells Squid how to operate
on a request. Seemingly simple changes can easily raise or lower the
response speed by whole orders of magnitude.

> 4.permanent configuration must has e separate file.

permanent as opposed to what? randomly thrown in changes to the network
layout? arbitrary changes to the access permissions? arbitrary changes
to the stored cache objects?

> 5.Write a web app for manage squid.

You will need to define and clarify "manage" if you want any more help
from use on that.

  cache content purges, start, stop, restart, rotate logs are all
triggered by asking Squid for certain cache manager URLs.
  statistical reports and network measurements are available at other URLs.

Run "squidclient mgr:menu" to see what is available to your app via
these HTTP cache_object:// URL requests from the cache manager. The data
reports are lists of current operating state. Some organized for humans
some for machine processing. For graphing things over time SNMP requests
are better to retrieve specific counter data.

> At least this project specifies the above and minimum maximum site and
> file and time.

time? That way lies danger. Beware the boss who says ALL object MUST be
delivered within 10 seconds. For one day you are sure to get a client
with 56K modem or satellite relay.

Cheers

Amos

-- 
Please be using
   Current Stable Squid 2.7.STABLE9 or 3.1.12
   Beta testers wanted for 3.2.0.9 and 3.1.12.3
Received on Tue Jun 28 2011 - 14:32:46 MDT

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