On Tue, Sep 01, 2015 at 12:42:35PM -0400, John wrote:
> Could they be sending a non-standard header of "-"

They could.

But if a request comes in without a User-Agent header, the logging
pipeline silently translates it into "-".

Have fun,
Christian



P.S.: The relevant configuration (for webrequests) is at

https://github.com/wikimedia/operations-puppet/blob/production/modules/role/manifests/cache/kafka/webrequest.pp#L26

That long line contains '%{User-Agent@user_agent}i', which means

  log the request's User-Agent header

but no default value is provided. As no default value is provided,
varnishkafka uses the pre-set default value, which is "-":

https://github.com/wikimedia/varnishkafka/blob/master/varnishkafka.c#L246

This conversion from the empty string to "-" does not kill relevant
information and is useful for some researchers when manually
inspecting TSVs, or manually browsing Hive output.



-- 
---- quelltextlich e.U. ---- \\ ---- Christian Aistleitner ----
                           Companies' registry: 360296y in Linz
Christian Aistleitner
Kefermarkterstrasze 6a/3     Email:  [email protected]
4293 Gutau, Austria          Phone:          +43 7946 / 20 5 81
                             Fax:            +43 7946 / 20 5 81
                             Homepage: http://quelltextlich.at/
---------------------------------------------------------------

Attachment: signature.asc
Description: Digital signature

_______________________________________________
Wikitech-l mailing list
[email protected]
https://lists.wikimedia.org/mailman/listinfo/wikitech-l

Reply via email to