tomcat-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Christopher Schultz <ch...@christopherschultz.net>
Subject Re: parallel deployment activation of new version
Date Wed, 25 Apr 2012 20:51:48 GMT
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Pid,

On 4/25/12 4:21 PM, Pid wrote:
> On 25/04/2012 15:57, Christopher Schultz wrote:
>> Pid,
>> 
>> On 4/23/12 9:50 PM, Pid wrote:
>>> On 23/04/2012 15:06, Christopher Schultz wrote:
>>>> Christoph,
>>>> 
>>>> On 4/22/12 11:55 AM, Christoph Maser wrote:
>>>>> Chris,
>>>> 
>>>>> Am Donnerstag, den 19.04.2012, 18:21 +0200 schrieb
>>>>> Christopher Schultz:
>>>>>> Christoph,
>>>>>> 
>>>>>> What about the webapp itself performing its own
>>>>>> health-check as a last step of deployment, and throwing
>>>>>> an exception (thereby preventing Tomcat from bringing it
>>>>>> into service) if things aren't in working order?
>>>> 
>>>>> this is the obvious way to do it as it is now. As I said 
>>>>> before that way one looses the access to the wapps status 
>>>>> pages.
>>>> 
>>>> So you want the webapp both up (for status) and down (for 
>>>> traffic) at the same time? Tomcat certainly can't manage that
>>>> for you.
>>>> 
>>>> If you need "status" on a failed-deployment, why not dump it
>>>> to a file or something like that?
>> 
>>> Or use JMX rather than HTTP to acquire status information.
>> 
>> In theory that sounds good, but the webapp needs to be deployed
>> in order to interrogate it via JMX. Once it's deployed, it's in
>> service (even if it's broken) and the system falls apart.
> 
> Which 'system falls apart'?

Sorry... shorthand for "new version is in service, and broken, and yet
it accepts new sessions which seems to be contrary to the OP's
requirements".

> JMX provides an alternative route to determine application status
> that is not impacted by whether the app is up or down.

Sure.

> If the app is not deployed there will be no associated MBeans.
> 
> If it is deployed but not running the status attribute of the
> WebModule MBean will indicate this.

Right. Are you suggesting that the webapp can fail deployment and
still be interrogated via MBeans? That's essentially what I'm
suggesting: have the webapp fail on deployment. OP is saying he wants
the webapp to deploy successfully so it can be interrogated via HTTP.

I think we both agree that is both a bad idea and not really workable
without big (and honestly unnecessary) changes to Tomcat.

> An HTTP connection is much less reliable and trying to do what the
> OP is asking is unlikely to provide a universally reliable result.
> 
> If the app is well behaved then it could start up enough to report
> it's health, given some components not starting properly - but I
> think the OP is asking for something else.

We'll see.

- -chris
-----BEGIN PGP SIGNATURE-----
Version: GnuPG/MacGPG2 v2.0.17 (Darwin)
Comment: GPGTools - http://gpgtools.org
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iEYEARECAAYFAk+YY+QACgkQ9CaO5/Lv0PAVZQCgq8cEG4d5/GlSP3htC2vlwnTi
kwUAmwaZoGcvPaCfUqw4rwJQ3he3OOpp
=IRZv
-----END PGP SIGNATURE-----

---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
For additional commands, e-mail: users-help@tomcat.apache.org


Mime
View raw message