On 02/08/2018 07:42 PM, Gabriele Cerami wrote:
On 08 Feb, Ben Nemec wrote:
So TripleO has a tech debt policy:
https://specs.openstack.org/openstack/tripleo-specs/specs/policy/tech-debt-tracking.html
(and I'm tagging tripleo on this thread for visibility).
I didn't know about this policy. I've been circling around tech debts
for more than a month now, and nobody pointed me to it either.
Anyway, I find it insufficient. Not specifically the tracking method,
but more the guidelines and the example, to understand how to use it
correctly.
Doing some basic research, I see that in tripleo 31 bugs were marked
with tech-debt tag. 15 Were closed, but they were also marked as
CRITICAL. This does not match my definition of tech-debt.
I would tend to agree. Tech debt is something you can live with for a
period of time, and critical bugs are not. The critical tech debt bug
open in tripleo at the time I'm writing this is clearly not critical
since it's been open for months and nothing has happened with it, nor
has it been blocking anyone from deploying or developing TripleO.
Of the remaining 16 sometimes it's hard to understand which part is the
technical debt, some are really new features requests matching more the
feeling "we may have needed to think about this months ago during the
design", for some it's just "we don't have a clear idea of what to do"
and the rest is "here's a bandaid, we'll think about it later"
The policy lacks a definition of what is a technical debt. I understand
the issue as it's really difficult to find a unique definition that fits
all we want to include.
Whatever the definition we want it to be, there are at least three things
that I want to see in tech debt bug (or report), and they all try to
focus on the "debt" part of the whole "tech debt" concept.
- What's the cost of the repayment
- What's the cost of the interests
- What's the frequency of the interests
For me a technical debt is an imperfect implementation that has
consequences. Describable and maybe measurable consequences.
"I'm using list in this case for simplicity but if we add more items, we
may need a more efficient structure, because it will become too slow"
The cost of the repayment is the time spent to replace the structure and
its methods with something more complex
The cost of the interests is the speed lost when the list increases
The frequency of the interests is "this list will become very big every
three hours"
Without these three elements it becomes hard to understand if we want to
really repay the debt, and how we prioritize the repayments.
Since a tech debt is something that I find really related to the code
(Which piece or line of code is the one that has these measurale
consequences) I'd really like for the report to be as close as possible
to the code.
Also sometimes it may just become a design choice based on assumptions.
"I know the list is not efficient, but we'll rarely get it big often,
and we are sure to clear it out almost immediately"
We can maybe discuss further the advantages of the existing bug tracking
for the handling of these reports.
Absolutely. Policies are not set in stone for all time. They're living
documents that can be updated as we find limitations or areas for
improvement. Please feel free to propose any updates you think would be
helpful to the existing policy. We can hash out the details in Gerrit.
I'm not sure I agree. Bugs stay open until they are fixed/won't fixed. Tech
debt stays open until it is fixed/won't fixed. We've had bugs open for
years for things that are tricky to fix. Arguably those are tech debt too,
but in any case I'm not aware of any problems with using the bug tracker to
manage them.
Remember the "debt" in "technical debt". You're not reporting it
correctly if you don't measure the consequences. I don't think the
report should really be about the problem or the solution, because then
you're really only talking about the full repayment.
Of course without any description on the consequences, the tech debt may
be equated to a bug, you really have a problem and you want to discuss
only its solution.
Another difference is that the importance of a bug rarely changes over
time, once correctly triaged.
With the technical debt instead
- A won't fix doesn't mean that the interests are gone. You closed the
bug/tech debt and you are not counting the interests anymore.
Convenient and deceiving. There is no status currently that could put
the bug on hold. Removing it from all the short term consideration,
but make it still count for its interests, make it possible to
consider and reevaluate at any time.
I don't think any bug should be closed as long as we have some interest
in fixing it. If it's not high priority then it should be triaged as
such, but I wouldn't advocate closing a bug just because we won't have
time to get to it this cycle/year/decade. :-)
The milestone field might be a good way to indicate that a bug is for
future reference but probably won't be dealt with in the short term. I
know I've seen projects that have a generic "future" milestone that
could be used to indicate we don't know when we'll get to it, but still
want to at some point.
- A tech debt really can get more and more costly to repay. If someone
else implement something over you "imperfect" code, the cost of the
repayment just doubled, because you have to fix a stack of code now.
Marking the code with a # TD may warn someone "be aware that someone
is trying to build over a problem"
I think we are in agreement that there needs to be some sort of notation
in the code to let people know that a given section is tech debt.
- The frequency of interests may increase also over time, and the
importance may raise as we are paying too much interests, and may be
better to start considering full repayment.
Sure, but I don't think you can solve this with a tracking system. It's
basically a question of re-triaging old bugs/tech debt regularly, and
given how much trouble we have keeping up with doing that for new bugs I
don't love our chances of doing it for old stuff.
I also don't think this is unique to tech debt. Bugs have their
priority changed all the time as people discover that they have more
serious consequences than initially thought or we find out that a lot of
people are running into a bug.
- One of the solution to a technical debt is "conversion": you just
render the imperfect solution just less imperfect, that is you don't
fully repay it, you repay just a little to lower the interests cost or
frequency. It's not a workaround, it's not a fix, you're just reducing
its impact. How do you report that in a bug tracking system ?
Partial-Bug: 1234567
Even better, since the commit message for such a change should include a
good explanation of how it is only a partial fix for the problem, you
shouldn't even need to explicitly leave a comment on the bug. The
gerrit bot will include the commit message as a comment when it merges.
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