comparing 2 headers

Tollef Fog Heen tfheen at redpill-linpro.com
Mon Jan 25 10:22:10 CET 2010


]] Angelo Höngens 

| 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? :)

It uses an LRU list to evict the object that's the longest since it
used.  This can impact performance somewhat as it often evicts a bit too
many objects at a time and like all kinds of garbage collections, happen
at a bad time, but it won't crash and burn.

| 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?

At the moment: just change varnishncsa and recompile.

| 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.

Upgrade.  This does work fine with at least 2.0.6 (just tested).

| 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.

http://varnish.projects.linpro.no/wiki/Varnishlog has the tiny start of
some docs.  Help writing up the description of all the tags would be
appreciated.

-- 
Tollef Fog Heen 
Redpill Linpro -- Changing the game!
t: +47 21 54 41 73



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