Re: [squid-users] Cache API

Hi Amos,

Thanks for the detailed response. This helps.

Thanks

On Fri, Jul 6, 2012 at 8:18 PM, Amos Jeffries <squid3_at_treenet.co.nz> wrote:
> On 7/07/2012 5:41 a.m., Abhishek Chanda wrote:
>>
>> Hi Amos,
>>
>> I need to have a list of all files cached in a network which has
>> multiple instances of Squid running. So, I was looking for an API to
>> query the cache and retrieve metadata about the files there. Is there
>> a better way to do this?
>
>
> "Files"? what files?
>
> HTTP is a generic information transfer protocol, not a file access protocol.
> Some of those resources are "files" on the origin server but the large
> majority are not even that. This is somewhat betrayed by that objects
> report, which would probably be called "files" if that were what Squid deals
> with.
>
> The well-known UFS storage model uses system files as places to store the
> cache data. But there is no relationship between the on-disk UFS filename
> and content stored there beyond a hash code in Squid memory. Squid uses
> these disk files like most programs use virtual RAM / swap disk, to swapout
> things (or bits of things) which may still be useful in future but are
> taking up too much memory space to keep there.
>
> The best way is to query the Squid manager component the cachemgr.cgi
> program is just a helper that does queries to access that information. The
> manager has a HTTP request based API.
> http://wiki.squid-cache.org/Features/CacheManager
> http://wiki.squid-cache.org/Features/CacheManager/Objects
>
> If you notice from that second page the example report, there is a mix of
> cached objects. Some have URLs, some only have file code numbers (eg "Swap
> Dir 0, File 0X00D05A"). HTTP is not restricted to web pages and most web
> pages are not actually built from storable files.
>
> For on-disk storage analysis there is squidpurge and ufsdump tools for
> UFS/diskd/AUFS cache storage model, cossdump tool in squid-2.7 for COSS
> storage model. We do not have anything currently to dump out a report of the
> new rock storage database content. The in-memory objects are in that
> vmobjects report.
>
> Amos
>
>
>>
>> Thanks for the link Waitman, I will look into it.
>>
>> Thanks
>>
>> On Fri, Jul 6, 2012 at 8:40 AM, Waitman Gobble <waitman_at_waitman.net>
>> wrote:
>>>
>>> On 7/6/2012 12:00 AM, Amos Jeffries wrote:
>>>>
>>>> On 6/07/2012 12:15 p.m., Abhishek Chanda wrote:
>>>>>
>>>>> Hi all,
>>>>>
>>>>> Does Squid have an API to query the content of the cache? I am aware
>>>>> of contentmgr.cgi, but I am looking for an API that I can call from my
>>>>> code.
>>>>>
>>>>> Thanks
>>>>
>>>>
>>>> Why would your code want to reach into the code of another program and
>>>> do
>>>> things?
>>>>
>>>> What are you trying to achieve?
>>>>
>>>> Amos
>>>
>>>
>>> Hi,
>>>
>>> An alternative you may want to check out is an e-cap module. Here is a
>>> simple example which stores the chunks in mongodb. It is possible to
>>> combine
>>> chunks into complete documents/etc however it seems to perform much
>>> better
>>> if you stuff the chunks and combine them later.
>>>
>>> https://github.com/creamy/ecap-mongo
>>>
>>> Waitman Gobble
>>> San Jose, California
>>>
>
>
Received on Sun Jul 08 2012 - 19:27:21 MDT