Startled by the observation that Hyperkitty's unit tests to fail because
an excessive amount of file descriptors are opened, I began to dig a little.
The majority of these file descriptors are opened by "Django Q" -- a
django library for asynchronous tasks.
I wondered what these asynchronous tasks might be in an e-mail archiver.
After all, it has to perform 2 very specific jobs:
1. Receive e-mails via http requests, process them, and store them in a
database.
2. Display the collected e-mails.
On top of that, it generates some statistics, includes a voting system,
and allows replying to e-mails in a forum-like fashion.
Job 1 really requires very little processing and is mostly database IO
as the message has to be sorted and its position in the thread has to be
computed.
None of this can be efficiently performed in the
background/asynchronously because there is nothing to be parallelized.
Performing the *whole* receive-and-store operation non-blocking also is
not an option -- ultimately mailman needs to know if it succeeded.
Job 2 is more or less what every web application does (reading from a
database and rendering the result) and certainly does not require any
asynchronous processing.
So where is Django Q used in Hyperkitty? It all boils down to the file
hyperkitty/tasks.py where a smaller number of asynchronous tasks are
defined.
They can be grouped into 3 classes:
- query mailman core
- repair the data structure (empty threads, orphans, ...)
- rebuild query cache
I would like to argue that none of these 3 groups of tasks need to be
performed asynchronously.
- Mailman-core only needs to be queried when mailing lists are changed.
This is triggered by signals from postorius and in addition periodically
by a cron job.
- The data structure should not need to be repaired in the first place
but the appropriate on_delete/on_save triggers should take care of this
-- and I believe they do in recent versions. If for some reason the
database becomes corrupted one can always start a repair operation.
Nothing is gained however, from running this asynchronously.
- Lastly the cache rebuild: Currently Hyperkitty rebuilds its cache
(which caches the db queries, not the frontend) whenever an e-mail is
received. Since it only involves *reading* from the db it actually is
something that *can* be done asynchronously to reduce the time it takes
to process an incoming e-mail.
But is it really worth the tremendous additional complexity that is
introduced by Django Q?
- requires a "qcluster" to run in the background (see shipped unit file)
- loss of determinism / debugging becomes much harder
- enourmous amount of file descriptors are opened in testing
- additional dependency
A similar result can be obtained by simply scaling the wsgi application
accordingly (if needed) and/or optimizing the db queries.
Alternatively one could simply invalidate the affected caches instead of
rebuild them every time an e-mail is received or don't trigger cache
rebuilds on received e-mails at all...
But maybe I overlooked something. I argue that we do not *need* Django
Q. The question is: do we want it?
What are your thoughts on this?
Best
Leon
On Tue, Mar 20, 2018, at 9:03 AM, Abhilash Raj wrote:
>
>
> On Tue, Mar 20, 2018, at 5:57 AM, Leon Merten Lohse wrote:
> > On 19.03.2018 23:30, Mark Sapiro wrote:
> > > I am trying to run
> > >
> > > tox -e py35-django111
> > >
> > > on HyperKitty. I run into an issue in that the tests run up to a point
> > > after which all but the last 2 fail with a "too many open files"
> > > exception. These files are logs created in directories
> > > /tmp/hyperkitty-testing-*, and over 100 /tmp/hyperkitty-testing-*
> > > directories are left behind. This is with an open file limit of 1024.
> >
> > It might look like that but the logs are not the actual problem as those
> > files are properly closed after the test finishes.
> >
> > I tried to disable logging to files all together but the problem persisted.
> >
> > The real cause for the excessive number of file descriptors is django-q,
> > which creates opens lots and lots of files (for inter process
> > communication?).
>
> It was trying to create File Descriptors and failing every time, but I
> am not 100% sure if that itself is the reason for this. It could be, but
> I can't replicate this issue easily,
What I meant was, I can replicate the issue but haven't yet been able to find something that fixes this issue.
I really shouldn't email before morning coffee.
> maybe filing a bug with django-q
> and seeing what they think might be worthwhile?
>
> >
> > Best
> > Leon
> > _______________________________________________
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> > https://mail.python.org/mailman/listinfo/mailman-developers
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> > Searchable Archives:
> > http://www.mail-archive.com/mailman-developers%40python.org/
> > Unsubscribe:
> > https://mail.python.org/mailman/options/mailman-developers/raj.abhilash1%40…
> >
> > Security Policy: http://wiki.list.org/x/QIA9
>
>
> --
> Abhilash Raj
> maxking(a)asynchronous.in
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>
> Security Policy: http://wiki.list.org/x/QIA9
--
Abhilash Raj
maxking(a)asynchronous.in
I am trying to run
tox -e py35-django111
on HyperKitty. I run into an issue in that the tests run up to a point
after which all but the last 2 fail with a "too many open files"
exception. These files are logs created in directories
/tmp/hyperkitty-testing-*, and over 100 /tmp/hyperkitty-testing-*
directories are left behind. This is with an open file limit of 1024.
If I raise the limit to 4096, everything runs and no
/tmp/hyperkitty-testing-* directories are left behind, but it seems
perhaps hyperkitty/tests/utils.TestCase._post_teardown() should have
something added to undo what hyperkitty/tests/utils.setup_logging() sets up.
--
Mark Sapiro <mark(a)msapiro.net> The highway is for gamblers,
San Francisco Bay Area, California better use your sense - B. Dylan
Hello,
I am interested in contributing enhancements around preferred address
to the REST API for version 3.1.x.
To prove out my use case(s) and familiarize myself with the code I have
made changes already. Here are some example curl command line
invocations and output to illustrate:
1) Create an address for an existing user and mark that address as the
user's preferred address:
curl -u restadmin:restpass \
-X POST \
-d email=skoranda(a)example.nil \
-d preferred=1 \
http://mytestbed.com:8001/3.1/users/e57ecfd0c0c74a319ac958b18882a6d8/addres…
This returns a '201 Created'.
2) Return the preferred address, if set, for a user:
curl -u restadmin:restpass \
-X GET \
http://mystestbed.com:8001/3.1/users/e57ecfd0c0c74a319ac958b18882a6d8 | python -m json.tool
{
"created_on": "2017-11-11T22:20:45.950949",
"display_name": "Scott Koranda",
"http_etag": "\"26bc0d9f21eb145248884aedae4c1ffd00b608d2\"",
"is_server_owner": false,
"password": "$6$rounds=656000$gWGfwpajfZ7rVn5O$Sl559B2TgtpJWXA2i67G5ukjzkV6iTp4NgP.6FJpMFMUTDdDXULAmwdN8YW92w87EdctgqFqAUkUqS6.EOTCz/",
"preferred_address": "skoranda(a)example.nil",
"self_link": "http://mytestbed.com:8001/3.1/users/e57ecfd0c0c74a319ac958b18882a6d8",
"user_id": "e57ecfd0c0c74a319ac958b18882a6d8"
}
3) Update/patch a user to set a preferred address:
curl -u restadmin:restpass \
-X PATCH \
-d preferred_address=skoranda(a)example.nil \
http://mytestbed.com:8001/3.1/users/e57ecfd0c0c74a319ac958b18882a6d8
This returns a '204 No Content'.
4) Get all addresses for a user with the preferred address (if set) having
the attribute 'preferred' set to 'true':
curl -u restadmin:restpass \
-X GET \
http://mytestbed.com:8001/3.1/users/e57ecfd0c0c74a319ac958b18882a6d8/addres… | python -m json.tool
{
"entries": [
{
"email": "skoranda(a)example.nil",
"http_etag": "\"492824d150f9f11e32d530d3cad0f76422bddb48\"",
"original_email": "skoranda01(a)example.nil",
"preferred": true,
"registered_on": "2017-11-13T22:35:17.232180",
"self_link": "http://mytestbed.com:8001/3.1/addresses/skoranda@example.nil",
"user": "http://mytestbed.com:8001/3.1/users/e57ecfd0c0c74a319ac958b18882a6d8",
"verified_on": "2017-11-20T16:48:51.738145"
},
{
"email": "skoranda01(a)example.nil",
"http_etag": "\"f0f28c1c6a925a595269d3fe21ef7fc1515d7670\"",
"original_email": "skoranda01(a)example.nil",
"registered_on": "2017-11-20T16:46:20.941262",
"self_link": "http://mytestbed.com:8001/3.1/addresses/skoranda01@example.nil",
"user": "http://mytestbed.com:8001/3.1/users/e57ecfd0c0c74a319ac958b18882a6d8",
"verified_on": "2017-11-20T16:46:20.941595"
},
],
"http_etag": "\"89c46bd312c6f1a344e6e6180aed6f11b62e6048\"",
"start": 0,
"total_size": 2
}
Before I submit a pull request I would be grateful for any comments
or feedback on the functionality as illustrated above, or any other comments
or feedback.
I will also begin the "copyright assignment" paperwork as explained at
https://wiki.list.org/DEV/Home
Thank you for your consideration.
Sincerely,
Scott Koranda
Hi,
I have followed the instructions at https://github.com/maxking/docker-mailman and copied the config files for exim4 from the core/assets/exim directory to /etc/exim4/conf.d/main. However, when I run update-exim4.conf I get the following error;
2018-03-08 14:28:59 Exim configuration error in line 238 of /var/lib/exim4/config.autogenerated.tmp:
main option "mailman3_router" unknown
Invalid new configfile /var/lib/exim4/config.autogenerated.tmp, not installing
/var/lib/exim4/config.autogenerated.tmp to /var/lib/exim4/config.autogenerated
After a bit of investigation I noticed that the mailman3 router and transport configurations appear before the begin router and begin transport sections in the autogenerate file. Is this expected? If not, how can I fix this?
–Kamran
