comparing 2 headers

[Angelo Höngens]

Hey,

I'm new to Varnish.. We currenly have 4 simple caching balancers running
squid+haproxy in front of some large webapps (2000 req/sec, 200Mbit),
and I get the feeling we're growing out of Squid..

So I am investigating an in-place replacement of Squid by Varnish. The
project looks really great, and the fact that the lead developer is such
a FreeBSD guru is really comforting as well ;) And yes, the talk about
the 1970's VAX machine approach to software architecture made a good point.

I have some questions though. I am used to Squid's way of doing thing,
so please forgive me if my questions are too biased to the squid-way of
doing things.


1. What will happen when the dataset I want to pass through Varnish is
much larger than the Varnish machines could store? I would expect the
cache hit ratio to go down, and Varnish to start evicting objects from
the cache more frequently. Or will Varnish just crash and burn with a
'cache is full' message? :)

The reason I ask this, is we have balancers with 200GB of local storage,
and the total amount of data that could be served could theoretically be
several terabytes.. I think objects would expire before the cache is
full, but just in case...


2. I run the varnishncsa daemon to write to logfile. However, I would
really like to see some extra information like whether it was a cache
hit or miss, and the last time to byte to the client in the logfile,
like squid does in it's access.log. This is really really handy for
post-mortem analysis. (We read everything into a database sometimes and
let the dba's do their thing.)

Is there any way to do this, or can you point me in the right direction?


3. I want to compare some headers, but I'm getting a compile error:

Message from VCC-compiler:
Expected CSTR got 'server.ip'
(program line 266), at
(input Line 1279 Pos 24)
  if (req.http.host == server.ip) { error 200 ok; }
-----------------------#########--------------------
Running VCC-compiler failed, exit 1
VCL compilation failed

I want to make sure that when I point my browser to http://w.x.y.z, I
get a message "200 ok". Am I doing something wrong? I'm using
Varnish-2.0.4 from ports by the way.


4. Is there some documentation on what the ReqEnd and StatSess values
mean in the varnishlog output? The values seem interesting, but I have
no idea what they are.




-- 


With kind regards,


Angelo Höngens
systems administrator

MCSE on Windows 2003
MCSE on Windows 2000
MS Small Business Specialist
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