Thanks Alex,
I will take more look at the code later on to make sure I understand the
process and find the specific debugs sections relevant to this specific
problem.
What I was thinking is that if there is a specific debug section that
checks the current cache file in the disk or gets the pointer etc,
I will start there to see what is causing squid to decide that the file
reading failed or any other thing in the file can cause it.
the next goal after I will find this bug cause will be to find what in
my code cause segmentation and crashes squid while doing some debugs
over details level 1.
Thanks,
Eliezer
On 11/13/2012 8:01 PM, Alex Rousskov wrote:
You asked for an example, and I found one. That particular example is a
good illustration of why a swap-in may fail, but it probably has little
or nothing to do with your specific problem.
>> From what was explained before the store index stores keys and not url,
>>am I right?
What is stored in a store index is kind of store-dependent so, ideally,
you should not care.
>>just throwing into the air, what are the steps when trying to find a
>>file in cache and serve it?
>>1. predict the hash of the request.(if store_url present to use it)
Yes, "calculate the store key" based on request information may be a
more accurate description. This happens as a part of
Store::get()-related API discussed in item #2 below.
>>2. lookup for the hash(get and head..) in the index?(memory? ufs? are
>>the same?)
Yes, see Store::get(), storeGetPublicByRequest(), and other related
storeGet*() and StoreEntry::get*() functions and methods. The Store
controller searches for the entry in various places, including memory
cache and disk caches.
>>3. read the file mentioned in the index from disk? by what?
>>(I have seen some code but not sure if it's the point I should look at)
Yes, the cached entry is swapped in from disk or from memory. The
specific code depends on the store (memory, ufs, Rock, etc.). For
disk-related stores, it all starts in storeSwapInStart() IIRC.
HTH,
Alex.
--
Eliezer Croitoru
https://www1.ngtech.co.il
IT consulting for Nonprofit organizations
eliezer <at> ngtech.co.il
