User:Mstone/Commentaries/Releases 1
Contents
Initial Unhappiness
m_stone> I take it that you guys are concerned that you'll have sugar in a
releasable state say around mid-June or early July?
m_stone> and that you'll be unable to make big changes for the remainder of
the 1-1.5 months until the release?
tomeu> well, I think the issue is not releasing something like last releases
tomeu> some thing that more or less works
tomeu> but having a better API and based on components that are more
predictable
tomeu> "something that more or less works" == "something that passes the
minimal QA work that has been done but that shows critical problems
after being deployed"
tomeu> we are not happy how new features have been rolled out
m_stone> tomeu: keep explaining, please. I really want to understand what
things look like from your vantage point.
m_stone> tomeu: (incidentally, that sounds more like a QA failure rather than
a software team failure to me.)
tomeu> m_stone: building on an orphaned component like the DS is not very
nice, either
tomeu> well, project issues that needs to be solved
tomeu> we cannot blame QA because it has been composed by interns
cjb> and is currently composed of no-one :)
tomeu> we already complained last summer about interns leaving just when
they started being useful
tomeu> I'm not happy with the parts of the sugar API that I have contributed
most, either
m_stone> tomeu: but help me understand how this affects the work you think we
should undertake to do for August 1 or the next release beyond.
Present Unhappiness
tomeu> m_stone: we want to have a software architecture more resilient to
bugs, more maintainable, and want to give activity authors a better
API
tomeu> m_stone: nothing of that are new features from the POV of the project
manager, I think
tomeu> m_stone: just dedicate time to it ;)
tomeu> discuss, discuss, discuss,
tomeu> then implement, deploy
tomeu> so well, we have a problem deciding on what to spend time
tomeu> every few months we are promised a new DS
tomeu> the activity API depends on that
tomeu> so it's not evolving and really sucks
tomeu> because depends on important implementation things like storing
entries with delta compression
tomeu> so well, we would like to better plan things, and spend effort in
invisible features
m_stone> tomeu: cscott, cjb, and I spent several minutes yesterday debating
whether cscott should try to fix networking things or DS things.
m_stone> (and consequently whether cjb should fix networking things or power
things)
m_stone> (and whether the kernel folks should fix power things or ???)
m_stone> (and whether I should concentrate on collaboration or
stability/compatibility things)
m_stone> tomeu: we have two plans and we haven't figured out yet which one is
better.
tomeu> m_stone: right, that's also our problem
tomeu> m_stone: I was supposed to work in the journal. but had to choose
between sugar, read, browse, ds, etc. at different points
tomeu> and performance
How should we allocate effort?
m_stone> marcopg_: plan a) is cscott, cjb, & kernel folks on networking,
mstone & collabora on collaboration, and sugar on ???
m_stone> where ??? is probably the as yet unspecified "UI features that are
already in the bag + any accessible stability"
m_stone> the other plan is cscott on DS, cjb on limited cases of power, kernel
folks on power, mstone on ???, and sugar on ???
marcopg_> I'm not sure I understand why we are going through the two extremes
about networking
m_stone> where I think ??? is the same as above.
cjb> I think there's a third plan of cscott, mstone and collabora on
networking, cjb and kernel on power, sugar on ???.
marcopg_> we certainly need someone on it, but I doubt putting the whole team
on it will help
m_stone> I'll try to answer marcopg's question and I'll try to explain the
other flaws here.
m_stone> first flaw: someone has to manage the release. at present, I'm the
default candidate (though feel free to suggest others)
m_stone> that's not immediately a full time job.
m_stone> but it will turn into one and we can't forget it. also, effort will
need to shift in the second half of the cycle toward making it
happen.
m_stone> i.e. I will need to impose on erikos, or cjb, or... :)
m_stone> (rather, whoever the release manager is will need to do so)
m_stone> second problem:
m_stone> there is lots of debate about how many people can profitably work on
networking, on power, on collaboration, on UI, on "stability", or on
"compatibility"
m_stone> in part, debate exists because there are different approaches to each
of these problems.
Power Management
m_stone> i.e. one way to do power is to make it work in limited circumstances
m_stone> I think of this as the "low-hanging fruit" approach
m_stone> that mainly requires cjb + some kernel, we think.
marcopg_> some kernel == not full time kernel person?
cjb> Yeah. I'd be surprised if we can't come up with an acceptable
limited/incremental use of power that takes less than a day to
implement. I'll try to write something about this.
cjb> For example, we don't do power management if you're currently
connected to a jabber server, else we do.
m_stone> the other way to deal with power (over a longer time frame) is to
comprehend the networking stack (so that we know what timeouts &
wakeups are needed), to fix the kernel to make those timeouts &
wakeups occur, then to do more userland power management
m_stone> similarly for networking.
Networking
morgs> Are the approaches mutually exclusive from a resource point of view?
cjb> (There are still the timeouts. It's hard to know how to tackle them,
when no particular misbehavior has ever been reported due to them.)
m_stone> one way to approach networking is to write down a believable
networking architecture, then to follow through.
m_stone> (where a believable networking architecture would contain a small
number of protocols that "stretch" to cover all of our present use
cases)
m_stone> the other way is to try to follow the critical path toward one use
case (e.g. reliable read sharing on a school server wifi with K/N
laptops)
m_stone> and to fix every damn bug you find along the way until it works or
until you recognize defeat
m_stone> the latter might get you a single working use case (or maybe 3), but
it's not going to get you reliability, stability, or leverage
m_stone> (they also take different amounts of time)
Focus or Divide and Conquer?
cjb> morgs: my third approach does a fairly even split of three groups
into three things
cjb> morgs: we can argue that this *sort* of approach has been the main
problem with OLPC software development
cjb> and has led to power management that doesn't really work, a mesh that
doesn't really work, collaboration that doesn't really work, and a
datastore that doesn't really work.
m_stone> and, as cjb alluded, we presently feel like we have N demos rather
than 1 solid product.
m_stone> some people believe this is because we sent N people in N+2
directions
m_stone> rather than either sending 10N people in N+2 directions or sending N
people in, say, 3 directions
marcopg_> I don't that's matter of people marcopg_> don't think marcopg_> it's matter of too many ambitious goals
tomeu> I don't think that having twice the number of people would have been
a waste of resources
tomeu> in many projects it is, but in our case...
m_stone> marcopg_: the complete absence of a QA team definitely made itself
felt here...
m_stone> (and the absence of software attacking the QA problem, e.g. test
suites)
tomeu> the absence of a DS maintainer, too
tomeu> the problem is that it depends on what we aim to do tomeu> and regarding sugar, we just don't know right now... tomeu> perhaps later today
marcopg_> let me rephrase
marcopg_> I don't think moving everyone to work on the network will help the
network a lot
marcopg_> at least on 4 months schedule
marcopg_> gradually adding people to the current team would be much more
sensible, ihmo
m_stone> marcopg_: a) I think scott proposes to make sure that every aspect of
networking has at least one person working on it; not to make
everyone work on it regardless of whether they are doing something
useful
m_stone> marcopg_: b) why, precisely, do you anticipate that (a) would fail?
m_stone> (or would be too expensive to pursue?)
marcopg_> because it takes time for people to figure out how to work together
in a productive way
marcopg_> if we have uncovered areas then we should cover them
tomeu> m_stone: do you think that many of our orphaned or under-resourced
areas can only be tackled efficiently for people already in the team?
m_stone> depends what you mean by "efficiently"
m_stone> specifically:
m_stone> I think that we have individuals who have the experience required to
'begin labor' on many areas.
m_stone> but I don't feel that they'll have the ability to close noticeable
numbers of bugs
tomeu> m_stone: in this case, without wasting most of the new resources'
potential
tomeu> if we talk about how to distribute resources, we need to characterize
every area as in how high is the entry point
tomeu> m_stone: some areas will require a longer effort to start being
productive, some less
marcopg_> m_stone: which aspects of networking we are not covering right now?
OLE Nepal: Journal & Datastore
BryanWB> hey guys, if you dont' mind i have a few ideas of where OLPC should
put its resources. I think OLPC should focus on the datastore and
Sugar over the next serveral months, whether that means putting all
or most of your human resources towards that. W/ the
datastore/Journal being most important.
BryanWB> the networking and power work well enough but it is fairly difficult
to use the Journal to find stuff. Also, in my week's worth of QA,
Sugar just does unexpected stuff
BryanWB> Over the last 2 weeks of working w/ os699, then 702, now 703. I have
had the most problems w/ the Journal/datastore then Sugar weirdness
marcopg_> I tend to agree with BryanWB, simply because the Journal is more a
base/fundamental use case then network sharing
marcopg_> i.e. losing your work is more critical then not being able to share
an activity
cjb> I think my counter-argument would be that if you live somewhere with
ample power, have a wireless AP and only one XO, of course you're
going to say that networking and power work fine. :)
BryanWB> cjp: we are using an AP not active antenna
cjb> BryanWB: Yes. That's why I say it's natural that you would think it
works fine.
cjb> What *doesn't* work is the mesh (non-AP) layer.
m_stone> (cjb: rather, our choice of protocols and implementations is
incompatible with the mesh)
m_stone> cjb: I speak relationally because I suspect that we are more likely
to change the protocols & implementations than we are to change the
firmware
BryanWB> cjb: I know, but that doesn't work anyway when you've got 70 XO's at
one school, AFAIK. mesh is less important than basic usability of
datastore
tomeu> BryanWB: I think peru's next deployments will use mainly mesh, but
I'm not sure
tomeu> BryanWB: that's another problem we have, knowing the very different
problems of every deployment location
BryanWB> tomeu: they can buy a small AP and power backup for Peruvian schools.
Power backup is pretty ubiquitous anywhere they have electricity and
load-shedding. ** at least in south and east asia ** don't know
south america
erikos> i think both are important use cases mesh and datastore and should
both be addressed
m_stone> erikos: sure, but in which order?
erikos> m_stone: well i hope that for august we can do both - at least parts
erikos> m_stone: we once started to provide mesh usability - and should
continue to push for it
erikos> m_stone: i think datastore should work is out of question
Feedback from Peru?
m_stone> so two questions: 1) what have the peruvian teachers discovered about
703?
m_stone> carla was clearly upset about a mesh bug.
marcopg_> m_stone: that's something that the deployment team should figure out
marcopg_> m_stone: we just don't have enough information at the moment to say
it
m_stone> marcopg_: in which case the priority should be to get that
information, yes?
m_stone> or to change the decision so that it's no longer necessary.
marcopg_> m_stone: I think that should be the priority, yeah
cjb> BryanWB: what about when the kids go home from school, though?
cjb> erikos: the problem is that no-one is confident we can get there by
pushing, rather than by throwing out what we have and redesigning.
cjb> erikos: I guess then we come to a question of whether the datastore
can also be made to work properly incrementally.
BryanWB> cjb: it needs to work at school first, that's where the other kids
are and they spend 8+ hours per day. Home should be a lower priority
cjb> since cscott's time is one of the main variables here, and he'd be
doing olpcfs.
m_stone> cjb: well, we might be able to have two people work on it.
m_stone> cjb: for example, one person could start implementing the testing!
marcopg_> cjb: that clashes with this "compatiiblity" requirement which has
been added for unknown (to us) reasons
erikos> cjb: sure - i mean if we feel we have to throw something out - we
might have to keep a beta solution in the hands as well
erikos> cjb: in the case of the datastore - if we decide we rewrite (i think
that is what people feel) we should start now
cjb> I think the short answer is that we shouldn't have to be making these
decisions ourselves. But if we write them up clearly enough, we can
pass the decision up the chain.
tomeu> having to choose between mesh and datastore is like choosing between
drinking or eating
tomeu> both are needed
What is "compatibility"?
m_stone> marcopg_: you say the "compatibility" requirement is "unknown"?
marcopg_> m_stone: I don't know why it has been suddenly added to the list of
top reqs
marcopg_> (I'm not against, I'd just like to understand better)
m_stone> marcopg_: first, let's make sure we mean the same thing. m_stone> compatibility means two things: m_stone> 1) our software running on other people's platforms m_stone> 2) other people's software running on our platform
m_stone> we mean both of these, I think. marcopg_> but there are a lot of possible approaches marcopg_> with pretty different end results marcopg_> and that's the main reason I want to know why it was pushed marcopg_> to figure out solutions that meets the exact requirements bemasc> cscott specifically referred to #2, not #1
Why do we want it?
m_stone> agreed that the reasoning behind making it a priority has not been
explained.
m_stone> I'll try to articulate the justification.
m_stone> 1) we wish more people were supporting our platform. We thing that
there are two ways to do this - first, to bring our software to them,
and second, to give them an immediate userbase running on our
platform
m_stone> 2) we're concerned, from time to time, that the days of funded
support for our platform are limited.
m_stone> therefore, we wish it to be less expensive to maintain.
marcopg_> how much limited?
marcopg_> 1-2 years or 1-2 months? ;)
m_stone> marcopg_: we've been greatly reassured on this point in recent weeks.
m_stone> marcopg_: (specifically by the fact that kim's budget was accepted)
m_stone> marcopg_: but I think that anxiety is a driving factor in the desire
to increase compatibility.
m_stone> marcopg_: as for your question: "both, with different liklihoods"
tomeu> we are having to guess too much, considering we have kids using the
laptops in the thousands
tomeu> and adding anxiety to the guessing...
m_stone> tomeu: I say the same thing all the time but I don't know what to do
about it.
m_stone> tomeu: the anxiety has greatly abated. we are now confident enough in
survival to begin hiring.
Who wants it and how?
marcopg_> m_stone: do we expect countries to actually deploy machines with
standard applications installed?
marcopg_> m_stone: and are we going to encourage or discourage it
marcopg_> the degree of compatibility we need is also an important factor for
the datastore work
marcopg_> even though I think we will be forced to do *something* about the
datastore situation by august
tomeu> m_stone: which legacy software needs to be run in the laptops and
which problems it has?
tomeu> if it's flash apps, then the compatibility stuff gains a totally
different meaning
tomeu> if it's java, we may have different problems than APIs
m_stone> marcopg_, tomeu: excellent questions which I do not have
authoritative answers for.
marcopg_> m_stone: ok, that's a question we need to answer I think
m_stone> no kidding.
How does it affect the DS (and other APIs)?
tomeu> m_stone: I wonder why the compatibility thing is so tied to a new DS
m_stone> tomeu: because of the desire to use the journal as the only
navigation tool pointing to local persistent data
tomeu> from my pov, the same mechanisms that olpcfs has for that, could be
added on top of the current implementation
tomeu> m_stone: we could add a fuse thingy on top of the current DS
m_stone> tomeu: I'm skeptical that the current DS would withstand that much
stress...
marcopg_> yeah what m_stone said
tomeu> m_stone: ok, I'm only concerned of mixing so many different issues
m_stone> tomeu: it's a good concern. I have no good answers for you :(
tomeu> we talk about compatibility, but do something because of performance
marcopg_> there is value in the idea of reusing the API though
marcopg_> and to start by fixing the implementation
m_stone> marcopg_: except for the fact that it's an API that we know is
terrible.
cjb> I don't think we should be too afraid about breaking APIs, if we have
a principled reason for doing it. It happens.
bemasc> I don't think there is very much legacy software worth using marcopg_> m_stone: it is, but we have tons of activities using it out there m_stone> marcopg_: not very many, actually. marcopg_> so in some way we will probably need to keep supporting it
tomeu> I'm perhaps the person who has suffered more because of the DS tomeu> but I have been promised lots of DS replacements tomeu> let me count them tomeu> 4 tomeu> 4 times I have been promised a DS, and have received only half
Can we drop the current DS?
marcopg_> m_stone: do you think we can drop it and ask authors to port? (real
question)
m_stone> marcopg_: yes.
cjb> And we can offer to update all activity code in our git repo to the
new one.
cjb> marcopg_: I think so too.
marcopg_> ok, I tend to agree
marcopg_> (I'm sure there will be people that don't though)
marcopg_> but that's fine
m_stone> marcopg_: I'm not sure that we should commit to doing much else. m_stone> marcopg_: but I think we could be confident of achieving that thing.
tomeu> I think there are cheap alternatives to breaking existing activities
tomeu> worth discussing, at least
m_stone> tomeu: I don't think there are cheap alternatives to breaking
activities that will noticeably improve stability.
m_stone> I don't really believe it.
m_stone> But I'm happy to hear your thoughts.
marcopg_> yeah that's a good point
tomeu> m_stone: using python namespaces, having daemons exporting two
different dbus interfaces, etc
m_stone> tomeu: what does that have to do with the causes of failure in the
present system?
m_stone> tomeu: (which I believe are primarily bitrot and invalid assumptions)
tomeu> m_stone: was referring to maintain API compatibility, while revamping
all of it
marcopg_> personally I think that if we are confident cscott can come up with
something solid by august, then it's totally worth to have him focus
on the ds
m_stone> marcopg_: I'm very confident in him (modulo the risk that he gets
sick, gets run over by a bus, gets "promoted", etc.) :)
m_stone> marcopg_: recall olpc-update
m_stone> marcopg_: once he understand a problem, he's quite difficult to stop.
marcopg_> then let's do it ;) and let's figure out how to properly resource
network without Scott, it doesn't seem impossible
erikos> m_stone: i think as well that it is worth to have at least one person
focusing on the ds reimplementation
bemasc> the high-level API will (read(), save(), etc.) will presumably remain
unchanged, so most activities won't require any modification
tomeu> bemasc: we have some problems with that API, I'm not sure yet how to
solve them
tomeu> m_stone: well, we overcome those by redesigning, and use those
techniques for old activities not breaking afterwards
m_stone> marcopg_: let's see if we can get some better information from the
deployment & sales folks first.
m_stone> marcopg_: even if it takes us a week to make a decision, it will be
time well spent if it winds up being a better decision.
m_stone> marcopg_: many times over.
marcopg_> m_stone: I agree
In more detail, what do we want?
bemasc> m_stone: it would be very nice to have a list of desired legacy-Linux
programs
bemasc> m_stone: the only ones I know of are gnumeric and inkscape
m_stone> bemasc: agreed. (though tomeu & marcopg rightly suggest that flash &
java might also be good compatibility targets)
bemasc> m_stone: well, flash doesn't write to disk, so it's immaterial. It's
essentially out of our hands
m_stone> bemasc: totally false. we can decide to ask developers to work on
gnash or not.
m_stone> bemasc: rsavoye has repeatedly said that gnash is shorthanded.
m_stone> bemasc: we've just never tried to actively assist him.
tomeu> about gnumeric, embedding it like we do with abiword shouldn't be
very complicated
marcopg_> tomeu: it would require to refactor the code heavily
tomeu> marcopg_: yeah, but how many months would take it to you?
marcopg_> tomeu: that doesn't scale
marcopg_> tomeu: we can't embed every possible application
m_stone> tomeu: this would not improve compatibility though.
tomeu> inkscape, had some memory usage problems that I don't know if have
been solved yet
m_stone> tomeu: scott apparently looked at inkscape when he was writing his
icon editor
m_stone> tomeu: he thinks it would be quite hard to sugarize
m_stone> (I don't fully understand why)
bemasc> but for both gnumeric and inkscape, the datastore is still not the
problem
bemasc> because both of them use the standard OS-provided open/save dialogs,
which sugar can substitute for DS-based dialogs
tomeu> marcopg_: I have heard gnumeric and inkscape, only
bemasc> marcopg_: there really aren't very many applications
marcopg_> it's not much a problem of existing applications
tomeu> marcopg_: we are getting back to the same point: we need to have
someone from the ministries of education to tell us which legacy
applications they feel the need for
tomeu> we are struggling to provide features that maybe nobody will
appreciate, while failing to provide the important ones
marcopg_> if I want to write a cool application for sugar
marcopg_> I know that it will be always confined to that platform
marcopg_> and honestly I can see how it's not an appealing perspective
marcopg_> we have the possibility to change this situation without a lot of
effort
marcopg_> and so I think we should do it
bemasc> marcopg_: yes. It's just a question of priority.
homunq> marcopg_++ on should, no opinion on can
tomeu> marcopg_: you, as a good software developer, will abstract the
platform dependent code
tomeu> ok, we more or less agree on the outcome, I think
marcopg_> tomeu: don't design your platform for very good software developers
tomeu> marcopg_: my point is not if we should do something or not, what I
mean is that I'm not convinced of the urgency of this code-on-xo run-
everywhere requirement
tomeu> the current DS API is insufficient no matter what we decide. and we
have already devised a scheme for legacy applications to store its
files in the journal
tomeu> where are we differing?
What compatibility might we try to provide?
marcopg_> I think it would make for a much better experience for developers
which start working on sugar
marcopg_> it would put us in a better position in the case of a end-of-funding
marcopg_> and it will make more likely that our applications are reused outside
sugar
marcopg_> I think those are pretty strong reasons
marcopg_> and I argue the effort is minimal
bemasc> tomeu: (I think we need to distinguish between legacy FD.o compliant
applications and legacy non-FD.o-compliant)
tomeu> marcopg_: we can make files dropped in ~/Documents to appear in the
journal as well as possible. but those apps won't be able to give a
so good experience as an activity
tomeu> no matter what we do
tomeu> "You created the document My Dog with the application Gimp" is not as
good as "You drawed My Dog with Tim and Silvia"
marcopg_> tomeu: apps not specifically designed for sugar will never give you
an as good experience as an activity, but that's fine
tomeu> as I said, we agree on what needs to be done
marcopg_> then let's just do it :P
How should we try to get there?
tomeu> and I think we agree in that the current DS API will need to be
scraped, right?
tomeu> well, the problem is that nobody is discussing what I think needs to
be discussed
marcopg_> tomeu: what do you think needs to be discussed... :)
tomeu> marcopg_: what will be the new API(s)
marcopg_> my suggestion about that would be to look into scott prototype
marcopg_> and build a prototype UI on the top of it
marcopg_> that would give us a much better base to discuss on
marcopg_> Scott is in charge of designing the API
marcopg_> more feedback he gets, better the API will be
marcopg_> I'm not really a fan of a long abstract discussion of an API, without
experimenting with it
tomeu> marcopg_: well, activity authors may be able to provide something
more close to their real needs
marcopg_> I don't think we are at the point where activity authors feedback is
useful, yet
marcopg_> when olpcfs is more mature, that will certainly be useful
Why is the current DS API unhappy?
Blaketh> tomeu: Can you point me towards some failings of the current DS API?
bemasc> activity authors are pretty much happy with the current high-level
API, which is what almost all of them use
bemasc> the only significant issue is an inability to save multiple files as
a single entry
marcopg_> bemasc: well that's your opinion. I heard a bunch of complaints about
the current API, and I've seen a bunch of confused developers
tomeu> Blaketh: see http://wiki.laptop.org/go/DatastoreOpenIssues
tomeu> being able to update a file without having to copy it around is one
missing point
tomeu> bemasc: we could use cow
bemasc> tomeu: every CoW filesystem copies the whole file on write
tomeu> bemasc: the issue here is API
tomeu> right now, activity authors need to copy the whole file to a temp
dir, modify it, and submit again to the DS
tomeu> it's the same at the end, but would be good if activity authors
weren't concerned about how the DS stores data
tomeu> the DS passes a path where the activity can read or write to
bemasc> so the DS should make the copy
tomeu> after the activity is happy with it, commits to the DS
tomeu> no matter if the activity is Read, VideoEditor, etc
bemasc> anyone thinking about legacy compatibility should know about
http://www.pygtk.org/docs/pygtk/class-gtkfilechooser.html
bemasc> Sugar can provide its own filechooser, thus integrating any GTK
application with the datastore without fancy filesystem footwork, and
without ever showing paths to the user
tomeu> bemasc: well, using the fs as a means for getting things into the
journal is better than that, right?
