admin@glassfish.java.net

Re: Admin meeting minutes (last week's)

From: Dies Koper <diesk_at_fast.au.fujitsu.com>
Date: Wed, 10 Mar 2010 13:21:22 +1100

Hi Byron,

I also made some notes last week:

Today's topic was cluster support for GF V3.1.

During the meeting we referred to the following document (which will
continuously be updated):

http://wiki.glassfish.java.net/Wiki.jsp?page=V3.1Clustering

For GF V3.1 we're planning cluster support without a Node Agent (NA).
At the later stage we could consider adding the Node Agent again.

Without a Node Agent, it will not be possible to start remote instances.
There was an idea to use ssh to replace that functionality from the NA,
but this will probably not be done in GFv3.1.

One of the main reasons to not including a NA is that people complained
about it. Not only because of issues they had and because it turned out
not to be as light-weight as it was initially intended to be, but users
say they prefer to register their instances with their OS's services
functionality (Windows service, etc.). This would give them behaviour
they are familiar with, and provide extra functionality, such as setting
the maximum number of times an instance should be restarted in case of a
failure.

Most of the discussion was about the way remote instances should
synchronise their files (and state) with the DAS.
In GF v2.x, the deploy process runs on the DAS and the remote instances
download the post-deployment (including generated) artefacts.
In GF v3.1, we want the remote instances to do the operations
themselves, so there would be less issues with file synchronization.

A potential issue with this approach is when deploying of applications
that require a lot of resources for deployment. For instance, JSPs can
be precompiled during deployment, and CMP applications access the DB for
schema generation. This will need to be investigated further
(performance comparison tests, etc.).

We can also consider optimizations like doing the deploy per DAS instead
of per
instance when the cluster's instances are on the same machine, and share
the files instead of each instance having its own copy.
Someone pointed out that this could create issues when redeploying an
application that is already running on a cluster instance. (Classes that
are in use would be overwritten).

For the file synchronization we would use the files' timestamps. For
complete subdirectories, only the subdirectories' filestamps would be
compared.

Discussion on this topic will be continued next week.

Regards,
Dies


On 10/03/2010 13:10, Byron Nevins wrote:
> Thanks! Yes -- the minutes are supposed to go on this same page:
> http://wiki.glassfish.java.net/Wiki.jsp?page=AdminIteam
>
> I'll copy & paste your minutes there...
>
> On 3/9/2010 5:42 PM, Dies Koper wrote:
>> Hi,
>>
>> Does someone keep minutes at the meetings?
>>
>> At http://wiki.glassfish.java.net/Wiki.jsp?page=AdminIteam I found a one
>> line minute for Kedar's last meeting, but no info about last week's.
>>
>> I made some notes that I can share if you can put them online.
>> I didn't keep a record of action items and attendees, and they only
>> cover the parts of conversations I could understand and/or was
>> interested in, but maybe better than nothing.