dev@glassfish.java.net

Questions about the Load Balance Plugin forGF V2

From: vince kraemer <Vince.Kraemer_at_Sun.COM>
Date: Wed, 23 Aug 2006 18:22:00 -0700

Satish,

I had a few questions about your presentation and slides...

First I want to make sure that I am not mistaken about the following:

Your presentation from slide 5 onwards applies to the Sun LB Plugin
(which is the first plugin listed on slide 4), right?

Slide 5:

Do you have an example of multiple cluster support? It looks like the
GUI can support it (slide 22). How does the CLI support it? Does the
user need to enter two arguments --target in a command like:
asadmin create-http-lb-config –target cluster1,cluster2
two-cluster-lb-config

Or, is there some command like "asadmin add-http-lb-config --target
cluster2 two-cluster-lb-config" (which would imply a "asadmin
remove-http-lb-config --target cluster2 two-cluster-lb-config", too)?

What asadmin command supports the 'configurable health check' feature?
GUI screen?

Is there a command that supports the 'configurable error pages' feature?
GUI screen?

If the user does configure custom error pages, that implies that they
need to be present on the machine that is balancing the load, right? Is
there a "best practice" for names/locations/content/whatever that we
should encourage folks to follow (or build tools to automate)?


Slide 6:

is there a stand-alone verifier for the loadbalancer.xml? Is there a way
to check the lbxml file BEFORE you plunk it onto a machine that has the
lb plugin installed?

Are all the customizations of the loadbalancer.xml file supported by CLI
commands and GUI screens? If they aren't, what percentage of them are?
If few of the customizations are supported, it seems like we need to
have a command like 'asadmin merge-http-lb-config –config
cluster1-lb-config "C:\loadbalancer.xml"', which would merge the data in
the file with the data in the DAS's cluster1-lb-config object.... Or is
there an 'asadmin import-http-lb-config -config foo-http-lb-config
"C:\loadbalancer.xml"' to read the content of a lbxml file and store it
in a DAS object?

Slide 10:

After the LB configuration is generated, how does it get to the machine
that is doing the LB? I kept hearing "copy manually".... which seems
primitive.

Is there any "magic" that users need to do to their apps to allow them
to be load-balanced? Conversely, is there any "bad magic" users could do
to their apps which would make them non-balancable? Does the
enable-http-lb-application check for those things (good and bad magic)?

Slide 12:

I read through the scenarios for upgrading apps. This looks like a
nightmare. What can be done to improve this area?

It seems like there are a number of steps that end up being manual...

For example: is there a way to push the new lbxml to an lb, instead of
doing a manual copy?

META QUESTIONS:

Is there a data overlap between the data in the loadbalancer.xml file
for "our" lb plugin and configuration files for some of the other load
balancers that you discuss on slide 4? If there is, could we create XSLT
"scripts" to automate this for users that have those other LB
configurations?

Will we create support for other popular LB approaches, like parallel
commands for mod_jk (visualize 'asadmin create-mod_jk-lb-config',
'asadmin export-mod_jk-lb-config' and more)? Is there a framework
available that would allow someone else to do that?

Do you have a set of use-cases for the features of the lb plugin?

Is there a dtd/schema for the loadbalancer.xml file? Is there any kind
of map between the elements of the lbxml and the asadmin commands that
manipulate the object created by the create-http-lb-config command?

Comment on the presentation:

Your presentation was very good.

One way to improve it would be to have discussed the user interactions
with the lb plugin a bit clearer. Your sample install/configuration was
good, but it just gets people started.

vbk

satish viswanatham wrote:
> Here are the slides for tomorrow's presentation.
>
> thanks
> Satish
>
> Nazrul Islam wrote:
>
>> Hi All,
>>
>> We will start the User Experience meeting from tomorrow (Aug 23).
>> Satish will be sending out the slides shortly. Please join us and
>> understand how to use clustering/loadbalancer in GlassFish v2
>> <https://glassfish.dev.java.net/downloads/v2-b13.html>. Also help us
>> evaluate issues with the current feature set in this space.
>>
>> Here are the meeting details...
>>
>> *Agenda:*
>> Wednesday, Aug 23, 2006 - Loadbalancer Administration
>> <http://www.glassfishwiki.org/gfwiki/attach/OnePagersOrFunctionalSpecs/LB-onepager.txt>
>> - Satish Viswanatham *
>> *
>>
>> *Time:*
>> 9 am - 10 am PDT
>>
>> *Dial-in Info:*
>> Toll Free Dial In Number: (866)545-5227
>> Int'l Access/Caller Paid Dial In Number:(865)673-6950
>> ACCESS CODE: 3535518
>>
>> *Conference Room:
>> *
>>
>> BLDG : SCA14
>> ROOM NAME : MAIN STREET USA
>> ROOM NUMBER/FLR : 2720/2
>>
>> *Future Agenda:*
>> http://blogs.sun.com/roller/page/nazrul?entry=starting_glassfish_user_experience
>>
>> If you would like to add something to the agenda, please let me know.
>> Thanks.
>>
>> --
>> Nazrul Islam - (408) 276-6468 - Sun Microsystems, Inc.
>>
>>