[Sugar-devel] new journal and datastore maintainer

[Martin Langhoff]

On Thu, Sep 17, 2009 at 4:27 PM, Gary C Martin <gary at garycmartin.com> wrote:
> FWIW, your three major points were fixed way back by Tomeu's 0.84 data-store
> re-write to make for robustness. Actually I'm fairly sure it was these
> kind'a reports that prompted Tomeu to make that fine effort. Prior to this
> (0.82) I had seen occasional datastore 'loss', sometime recoverable,
> sometimes not (while stress testing 3 XOs here). But since 0.84 I've not
> seen any failures.

Somewhat in agreement. Clearly, there have been huge efforts -- and
huge thanks go to Tomeu. That is the good side.

But a rewrite is always a risky business. Got to channel jwz here and
link to this oldie: http://jwz.livejournal.com/154529.html

A rewrite means we have to approach the new DS as a new piece of
software (or library or service or component). May fix some bugs, may
add others -- new code new bugs. Hasn't seen the field. And for
example, cannot be easily backported for a trial run in a deployment,
and/or to be incorporated into my "papercuts" release.

> I guess we're waiting on the OLPC timeline for an official XO signed release
> with 0.84, before deployments would be comfortable moving forward with the
> solution. 0.84 is just about 6 months old now, so happy half Birthday! :-)

You are right there. But I would like to note that any widely deployed
software has a very long "release/deploy" cycle. This happens on OLPC
deployments, and will happen on all large deployments.

The DS is a very important component. When we see dataloss bugs, we
need a patch for the deployed version, and a "rescue my data" utility.

"It is rewritten in the next release" is -- in practice -- not very
useful. There is no fix for the users in any reasonable timeframe. And
in fact, we don't know how that rewrite will work in the field.

This is not to disparage Tomeu's work. It is positive, and necessary.
But when we think about users and deployments, there is an aspect that
is actually more important: getting a fix and a 'repair' path out to
users, in a way deployments can use.

The current situation with this specific issue is understandable,
8.2.x was of course released at a time of turmoil for us all, and the
DS rewrite was done shortly after.

So I am strictly looking forward -- and wondering if we can help these
users of 0.82 now. And how we'll handle similar issues when 0.84 is
deployed and if dataloss bugs are reported.

cheers,


m
-- 
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 martin at laptop.org -- School Server Architect
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