Re: Squid 3.2 performance question

On 24/03/2012 7:44 a.m., Henrik Nordström wrote:
> fre 2012-03-23 klockan 19:49 +0400 skrev Alexander Komyagin:
>
>> It seems I finally figured out where the problem is. Squid 3.2.0.16
>> performs host verification for each request. And this verification
>> produces the call to libc getaddrinfo() function (converting IP address
>> from text to numeric in my case), but uClibc implementation of this
>> functions looks like not aware of AF_HOSTNUMERIC hint flag, thus
>> performing full lookup (I haven't checked details yet). With RSBAC-Net
>> turned on it's too much overhead. (Actually there are two calls for such
>> conversion per request - one more is in url.cc:urlParseFinish()
>> function)
> Why is the overhead with RSBAC-Net that high in this case?
>
> getaddrinfo() is a quite frequenty used call.
>
> But I agree that getaddrinfo for converting textual ip to addrinfo to
> compare with resolved hostname may be a bit overkill. Not even sure why
> we are converting textual IP to to addrinfo there, we should already
> have it in IpAddress internal representaion form.

getaddrinfo() is how we parse "Host: 10.0.0.1" or "http://10.0.0.1/"
into that internal form.

Being the POSIX way to parse (domain|IP) patterns it is used anywhere we
might encounter that pattern. So if this does pan out to be uClibC we
may need to detect this brokeness and use the bundled getaddrinfo()
implementation.

Amos
Received on Fri Mar 23 2012 - 22:51:02 MDT