health check path doesn't change after VCL reload (2.0.6)

[Caunter, Stefan]

Confirmed. Changing director load balance logic, backend membership, and
backend health checks requires a restart. Makes for exciting times if
you need to change .probe parameters on the fly when varnish thinks all
your backends are sick.

 

Stefan Caunter :: Senior Systems Administrator :: TOPS

e: scaunter at topscms.com  ::  m: (416) 561-4871

www.thestar.com www.topscms.com

 

From: varnish-misc-bounces at varnish-cache.org
[mailto:varnish-misc-bounces at varnish-cache.org] On Behalf Of Ken
Brownfield
Sent: July-28-10 9:48 AM
To: John Norman
Cc: Varnish misc
Subject: Re: health check path doesn't change after VCL reload (2.0.6)

 

I also recently confirmed that the backend specs aren't reset with a VCL
reload.  We had a backend timeout that was too short, but we had to do a
hard restart of all instances to pick up the change.  Not the end of the
world; worst case this might belong on the wiki.

 

The code to modify or respawn backend threads might be somewhat
complicated, but it's probably worth it, IMHO.

-- 

Ken

 

On Feb 24, 2010, at 1:25 PM, John Norman wrote:





No, only the former / old path.

I'm not super-troubled right now because a Varnish restart did pick up
the new path (but at the cost of my cache) -- but I'm a bit worried
about the next time I have to change it.

I will be changing the probe interval soon, so that will give me a
chance to reproduce the problem, if it even exists.

As a bit of background:

I automate the VCL update to multiple servers, when/if the VCL file has
changed.

Before the update, I also remove all of the inactive/old VCL's that are
sitting there.

Then I add the new one and "use" it.

When I observed in my backend logs the probes going to the old URLs, I
did check the "active" VCL on all systems, and they all showed the new
path.

In any case, I will try to reproduce and will send the results.

One last thing: During the restart on one system, I observed the issue
reported here:
http://zarathustrashallspeak.com/2009/11/28/varnish-startup-issue/

John

On Wed, Feb 24, 2010 at 4:18 PM, Poul-Henning Kamp <phk at phk.freebsd.dk>
wrote:

In message <b6b8b6b71002241315w1c62022t1bf941d6f2cac0c7 at mail.gmail.com>,
John N

orman writes:

>Still, the VCL indicated as "active" had a different path for the
health
>check.

Hopefully both got probed ?

--

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by
incompetence.

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://www.varnish-cache.org/lists/pipermail/varnish-misc/attachments/20100728/abf97f17/attachment-0003.html>