Mailinglist Archive: opensuse-buildservice (262 mails)

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Re: [opensuse-buildservice] Re: Notifications (was: Re: [opensuse-packaging] New packages for factory)
  • From: Johannes Meixner <jsmeix@xxxxxxx>
  • Date: Tue, 11 Aug 2009 16:39:43 +0200 (CEST)
  • Message-id: <alpine.LNX.2.00.0908111604400.31749@xxxxxxxxxxxxxx>


On Aug 11 15:03 Adrian Schröter wrote (shortened):
Am Dienstag, 11. August 2009 12:45:57 schrieb Johannes Meixner:
On Aug 11 10:50 Adrian Schröter wrote (shortened):
Am Dienstag, 11. August 2009 10:34:58 schrieb Johannes Meixner:
One needs transaction semantics when working on packages:
1. Begin of transaction
2. Change it
3. End of transaction

This isn't there by intention. Basically no scm implements it because it
blocks other people and slow downs development. Usually first submitter
wins and followers need to adapt.

I can not imagine any system right now, which solves social problems, in
the end people need always to talk to each other if they work on same

A weak synchronization point preferably with a kind of weak locking
before someone starts to change it (so that all others who also
work on it are at least informed) and a strong synchronization point
preferably with a kind of three way merge when changes are committed.

I do not understand how a weak synchronization point before
blocks other people and slow downs development.

The problem with the current build service is not the
optimistic concurrency control policy at commit time,
the problem is that nobody knows about others who may also work
on a package until it is too late to start collaborating.

Remember Coolo's mass-changes of packages.
All others notice what Coolo did only when it was already done.
If there was a "begin of transaction" the others could get
at least informed before.

I fail to see how a package locking would help here.

I never requested hard locks.
A "Begin of transaction" does not require locks.

Transaction semantics is "all or nothing", i.e. either all
changest between "Begin of transaction" and "End of transaction"
are committed or nthing at all.

Transaction semantics works well with an optimistic concurrency
control policy (i.e. first commit wins).

Transaction semantics with optimistic concurrency control would do:

1. Begin of transaction for package foo
Remember the current write time stamps for all files of package foo

2. Read whatever files of package foo are needed
and change a local copy of them.

3. End of transaction for package foo
Do a hard lock for all files of package foo on the server
Compare if a write time stamp for one of the files
which was locally changed did already change on the server and
if yes do not change anythjing on the server
if no write the locally changed files onto the server
and finally release the lock.

It would use by the
script, so it would briefly lock the package and than submit it. Not much time
in between.

The hard lock happens only while a transaction is
at the end finally in it commit procedure.

Therefore we have the source links and devel projects, one get the changes
(either automatically or by manually solving via repairlink).

But as you wrote - and as other threads here show - mutual information
is not really within the scope of the build service but is left to the
users of the build service to do it somehow on their own beside the
build service via manual mails.

We can discuss to have something like a "I am currently working on this
package" flag, but I strongly mind to block something.

Exactly what I ask for.
I just want to be informed who else works on a package
while I am working on it.

What I have in mind is a kind of "current workers list" on the server
which contains who currently works on a package.

1. Begin of transaction
1a) Lock the current workers list (for read and write)
1b) Test if current workers list is empty
1b1) if empty, continue with step 1c
1b2) if not empty, show me the current workers list
and ask me if I like to work on it additionally
and wait (on the server) up to 1 minute for my response
1b2a) if response is "no" or if timeout,
unlock the current workers list
and cancel the transaction
1b2b) if response is "yes", continue with step 1c
1c) Add myself to the current workers list
1d) Send the current workers list to all current workers
1d) Unlock the current workers list
1f) Create local copy (i.e. "Read")
2. Modify local copy
3. End of transaction
3a) Lock
3b) Test if modifications do not conflict (i.e. "Validate")
3b1) if no conflict, write modifications (i.e. "Write")
3b2) if conflict, ignore modifications (loss of work)
3c) Unlock
3d) Remove myself from the current workers list
3e) Send the current workers list to me and all current workers

The two kind of "send the current workers list" messages should
be processed by hermes (i.e. one can suppress them).

Perferably each worker could provide an optional notification
which is also stored in the "current workers list"
what the reason is why he works on a package like
"fixing bnc#12345".

In contrast in my own working copy directory

jsmeix@nelson:/obs/Printing/cups $ osc log

shows more info but still not my "osc commit" messages.
In my own working copy directory I do not need such information
very much because in my own working copy directory I know well
what I did there.

huh ?

When I do "osc commit", there is a commit message which defaults
to the differences in the changes file. I leave at least the default
but often I add something more.

# osc log Printing
r170 | autobuild | 2009-07-31 19:04:44 | 8c3f68c5fe8d9e82ec6fb6aa07a8971e |

checked in
r169 | jsmeix | 2009-07-31 15:22:11 | 5df4c71fb22b1a8ddd1d76ed399d9b79 |

Copy from home:jsmeix:branches:Printing/cups via accept of submit request
Request was accepted with message:
Fixed major bug bnc#526847
r168 | autobuild | 2009-07-29 17:20:30 | 8c3f68c5fe8d9e82ec6fb6aa07a8971e |

checked in

In contrast it is crucial to have meningful "osc log" messages
when I query whatever package on the server to find out which
revisions are of particular interest regarding a particular issue.

what do you miss exactly ?

I do not mean the request messages but my "osc commit" messsages.

I would like to have the diff of the changes file as the minimum
of meaningful "osc log" messages.

"osc help log" reads "Shows the commit log of a package" but
currently it seems "osc log" does not show a log regarding
what has changed inside a package (i.e. its changelog)
but a log regarding what happened to a package in the obs
i.e. whereto it was submited and if it was accepted and so on
but according to my understanding this is not the commit log
but a submit log.

The use case which I have in mind is:

End-user jane runs out there whatever package from the obs.
I get a bug report from her.
I let her send me "rpm -q --changelog" and therein I find
a suspicious entry:

* Wed Jan 14 2009 johndoe@somewhere
- removed various obsolete stuff

Now I want to know exactly what johndoe did at that time.

My first problem is to find out the osc revision which matches
to this RPM changelog entry. I don't know a direct way to get it.

If I had the RPM changelog differences as the absolute
minimum in the "osc log" output, I could do an appropriate
"osc rdiff" but currently I have no idea - except dumb trial
and error - how to get what johndoe did at that time.

Kind Regards
Johannes Meixner
SUSE LINUX Products GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
AG Nuernberg, HRB 16746, GF: Markus Rex
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