[Koha-devel] Optimizing Starman startup
dcook at prosentient.com.au
dcook at prosentient.com.au
Mon Apr 26 09:11:41 CEST 2021
So I just tried the following…
--
root at kohadevbox:koha(master)$ npm install -g swagger-cli
/usr/bin/swagger-cli -> /usr/lib/node_modules/swagger-cli/swagger-cli.js
npm WARN @apidevtools/swagger-parser at 10.0.2 requires a peer of openapi-types@>=7 but none is installed. You must install peer dependencies yourself.
+ swagger-cli at 4.0.4
added 46 packages from 27 contributors in 8.203s
--
root at kohadevbox:koha(master)$ time swagger-cli bundle api/v1/swagger/swagger.json --outfile api/v1/swagger/openapi.json --type json
Created api/v1/swagger/openapi.json from api/v1/swagger/swagger.json
real 0m0.296s
user 0m0.346s
sys 0m0.032s
openapi.json is 10891 lines long but it actually contains 741 $ref lines like "$ref": "#/definitions/error" and "$ref": "#/definitions/patron_extended_attribute".
--
Now to do some benchmarking… I ran the following code:
#!/usr/bin/perl
use JSON::Validator::OpenAPI::Mojolicious;
my $validator = JSON::Validator::OpenAPI::Mojolicious->new;
my $spec = $validator->bundle({
replace => 1,
schema => "api/v1/swagger/swagger.json",
});
The first time I ran it… it took 1.343 seconds. The second time and subsequent times it took .354 seconds. (That’s using Ubuntu 20.04 and JSON Validator 3.14.) That suggests caching although I’m not sure where. I don’t see anything obvious in /usr/share/perl5/JSON/Validator/cache.
Trying with openapi.json yields .280 seconds instead of .354 seconds. It’s faster, but not significantly.
So that suggests that the problem is actually with Koha::REST::Plugin::PluginRoutes or Mojolicious::Plugin::OpenAPI more specifically…
David Cook
Software Engineer
Prosentient Systems
Suite 7.03
6a Glen St
Milsons Point NSW 2061
Australia
Office: 02 9212 0899
Online: 02 8005 0595
From: dcook at prosentient.com.au <dcook at prosentient.com.au>
Sent: Monday, 26 April 2021 11:24 AM
To: 'Renvoize, Martin' <martin.renvoize at ptfs-europe.com>
Cc: 'Koha Devel' <koha-devel at lists.koha-community.org>
Subject: RE: [Koha-devel] Optimizing Starman startup
I think that I accidentally offended him, as he hasn’t responded to me since his initial response.
I do wonder if reducing the number of references would help, although I wonder how easy that would be to do in practice. It looks like we have about 5767 lines of JSON all up as is… so it would probably get even bigger if we dereferenced them.
Oh… here’s a thought. Why don’t we compile it? According to https://davidgarcia.dev/posts/how-to-split-open-api-spec-into-multiple-files/, you can maintain many different files, and then use something like swagger-cli to create a single built/compiled OpenAPI file.
That way JSON::Validator wouldn’t need to resolve any references for the core API. I don’t know if the plugins have any $ref in them but I’m guessing not (just based on Coverflow). So that could be a big win.
I’m working on other things at the moment, but I’m going to put that on my eternal list.
David Cook
Software Engineer
Prosentient Systems
Suite 7.03
6a Glen St
Milsons Point NSW 2061
Australia
Office: 02 9212 0899
Online: 02 8005 0595
From: Renvoize, Martin <martin.renvoize at ptfs-europe.com <mailto:martin.renvoize at ptfs-europe.com> >
Sent: Friday, 23 April 2021 5:24 PM
To: David Cook <dcook at prosentient.com.au <mailto:dcook at prosentient.com.au> >
Cc: Koha Devel <koha-devel at lists.koha-community.org <mailto:koha-devel at lists.koha-community.org> >
Subject: Re: [Koha-devel] Optimizing Starman startup
Jan's code is certainly challenging to read and understand at times I agree.. I used to contribute to the plugin a number of years ago now.. but the project that gave me time to play with that has since been sold on so I'm not involved at the level I used to be.. he uses lots of Perl foo which often takes me a long time to wrap my head around.
As for the refs, I think we split our spec up too much in all honesty.. even the swagger spec suggest we went too far.. I think I might have been unclear when I first pushed for a split from one massive file. We could/should certainly reduce that somewhat.. it'll be interesting to see if it makes much difference.. that could be a fairly quick win.
On Thu, 22 Apr 2021, 12:32 am , <dcook at prosentient.com.au <mailto:dcook at prosentient.com.au> > wrote:
Hi Ere,
I think you're right about the refs. While they get resolved by the OpenAPI plugin, you probably have to resolve them before trying to dynamically inject the routes from plugins.
Jan Thorsen (the author of Mojolicious::Plugin::OpenAPI and JSON::Validator) thinks that the ref resolution is actually what's taking so long. I looked it up and I think we have over 400 different references in the main OpenAPI spec alone. I haven't profiled it but something to think about.
At some point, I'm going to have a play with newer versions of the modules. I'm gong to look at Ubuntu 20.04 and newer Debian versions to see what I can get away with in terms of newness. Needs more investigation, but I am really hoping that this is an issue that can be solved by just upgrading the OS.
I find Jan's code to be unnecessarily opaque (could use more descriptive comments and function naming) but... I'll investigate. Probably not right away as I have a bunch of other priorities that I have to address but... this is on my mind.
Starman startup time is probably the thing about Koha annoying me the most right now and probably the most practical thing I can improve at the moment...
David Cook
Software Engineer
Prosentient Systems
Suite 7.03
6a Glen St
Milsons Point NSW 2061
Australia
Office: 02 9212 0899
Online: 02 8005 0595
-----Original Message-----
From: Ere Maijala <ere.maijala at helsinki.fi <mailto:ere.maijala at helsinki.fi> >
Sent: Wednesday, 21 April 2021 6:31 PM
To: dcook at prosentient.com.au <mailto:dcook at prosentient.com.au> ; koha-devel at lists.koha-community.org <mailto:koha-devel at lists.koha-community.org>
Subject: Re: [Koha-devel] Optimizing Starman startup
Hi David,
I wish I'd remember all the details, but my memory fails me. I think not using JSON had something to do with how the refs are resolved. That may or may not have been the reason, but if everything works with JSON module, I can't think of a reason not to use it.
Thanks for taking a look!
--Ere
dcook at prosentient.com.au <mailto:dcook at prosentient.com.au> kirjoitti 21.4.2021 klo 3.28:
> Hi Ere,
>
> Thanks for your reply. 24700 looks much better. I'll look at backporting it locally.
>
> Although I'm looking at JSON::Validator::OpenAPI::Mojolicious at https://metacpan.org/pod/release/JHTHORSEN/Mojolicious-Plugin-OpenAPI-2.19/lib/JSON/Validator/OpenAPI/Mojolicious.pm and it says "Do not use this module directly. Use Mojolicious::Plugin::OpenAPI instead." I notice that you're using the "bundle" method. Do we really need that there? Why don't we just load the JSON using the JSON module, merge with the plugin spec files, and then pass it to the OpenAPI plugin? Shouldn't the plugin take care of the $ref replacement?
>
> Hmm... I didn't realize until now that the OpenAPI plugin was doing a validate behind the scenes. That's tricky.
>
> At a glance, we might be able to pre-load the app into the Starman
> master process pre-fork. There are warnings about doing that with open
> database connections, so we'd need to review plack.psgi, but a quick
> glance suggests it might be OK. (Alternatively, I have wondered about
> running the REST API as a separate process apart from Starman using
> hypnotoad. According to
> https://docs.mojolicious.org/Mojolicious/Guides/Cookbook,
> Mojo::Server::Prefork preloads the application in the manager/master
> process, and Hypnotoad is based off that, so that would help.)
>
> It does seem like changes to the OpenAPI plugin would be needed for caching.
>
> I'm going to try backporting your change and try pre-loading and see how far that gets me.
>
> David Cook
> Software Engineer
> Prosentient Systems
> Suite 7.03
> 6a Glen St
> Milsons Point NSW 2061
> Australia
>
> Office: 02 9212 0899
> Online: 02 8005 0595
>
> -----Original Message-----
> From: Koha-devel <koha-devel-bounces at lists.koha-community.org <mailto:koha-devel-bounces at lists.koha-community.org> > On
> Behalf Of Ere Maijala
> Sent: Tuesday, 20 April 2021 4:48 PM
> To: koha-devel at lists.koha-community.org <mailto:koha-devel at lists.koha-community.org>
> Subject: Re: [Koha-devel] Optimizing Starman startup
>
> Hi,
>
> I did some work on improving it here:
>
> https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=24700
>
> That shaved a good bit of time from it, but it's still a heavy
> operation, and it would make sense to
>
> 1.) avoid doing it too often
>
> 2.) cache the results and avoid doing it if results are cached
>
> If you could address the first one, that'd go a long way. I'm afraid the second one would require changes to the OpenAPI plugin to support caching.
>
> --Ere
>
> dcook at prosentient.com.au <mailto:dcook at prosentient.com.au> kirjoitti 20.4.2021 klo 6.15:
>> Hi all,
>>
>> Do you despair when you see the following periodically in “top” when
>> a starman worker is recreated ?
>>
>> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+
>> COMMAND
>>
>> 9529 my-koha 20 0 460108 197212 17172 R 100.0 0.4 0:03.41
>> /usr/share/koha/api/v1/app.pl <http://app.pl>
>>
>> Or the following in top when you install koha-common package or
>> restart the koha-common service?
>>
>> 11101 1-koha 20 0 447232 193320 16076 R 10.6 0.4 0:09.09
>> /usr/share/koha/api/v1/app.pl <http://app.pl>
>>
>> 11168 1-koha 20 0 447240 193264 16056 R 10.6 0.4 0:08.72
>> /usr/share/koha/api/v1/app.pl <http://app.pl>
>>
>> 11306 2-koha 20 0 447220 193148 16000 R 10.6 0.4 0:08.07
>> /usr/share/koha/api/v1/app.pl <http://app.pl>
>>
>> 11543 2-koha 20 0 447232 193036 15828 R 10.6 0.4 0:07.07
>> /usr/share/koha/api/v1/app.pl <http://app.pl>
>>
>> 11784 3-koha 20 0 441536 189664 16172 R 10.6 0.4 0:06.04
>> /usr/share/koha/api/v1/app.pl <http://app.pl>
>>
>> 11830 3-koha 20 0 439548 187212 15748 R 10.6 0.4 0:05.82
>> /usr/share/koha/api/v1/app.pl <http://app.pl>
>>
>> 11831 4-koha 20 0 438620 186344 15748 R 10.6 0.4 0:05.81
>> /usr/share/koha/api/v1/app.pl <http://app.pl>
>>
>> 11853 4-koha 20 0 437680 185672 16000 R 10.6 0.4 0:05.79
>> /usr/share/koha/api/v1/app.pl <http://app.pl>
>>
>> Well, I still have a lot of investigation left to do, but I notice 1
>> place that a lot of time taken is here (per worker):
>>
>> my $validator = JSON::Validator::OpenAPI::Mojolicious->new;
>>
>> $validator->load_and_validate_schema(
>>
>> $self->home->rel_file("api/v1/swagger/swagger.json"),
>>
>> {
>>
>> allow_invalid_ref => 1,
>>
>> }
>>
>> );
>>
>> push @{$self->routes->namespaces}, 'Koha::Plugin';
>>
>> my $spec = $validator->schema->data;
>>
>> $self->plugin(
>>
>> 'Koha::REST::Plugin::PluginRoutes' => {
>>
>> spec => $spec,
>>
>> validator => $validator
>>
>> }
>>
>> );
>>
>> $self->plugin(
>>
>> OpenAPI => {
>>
>> spec => $spec,
>>
>> route =>
>> $self->routes->under('/api/v1')->to('Auth#under'),
>>
>> allow_invalid_ref =>
>>
>> 1, # required by our spec because $ref directly
>> under
>>
>> # Paths-, Parameters-, Definitions- &
>> Info-object
>>
>> # is not allowed by the OpenAPI specification.
>>
>> }
>>
>> );
>>
>> Anyone have ideas for improving this? Do we have to validate the
>> schema every time? Can we move the schema validation into a different
>> module and preload it into Starman using the -M flag so that it’s
>> done
>> 1 time per Starman master instance rather than 1 time per Starman worker instance?
>>
>> I find “/usr/share/koha/api/v1/app.pl <http://app.pl> ” to be the bane of deployments,
>> as it puts a massive load on a server, when you have multiple Koha
>> instances on the server.
>>
>> David Cook
>>
>> Software Engineer
>>
>> Prosentient Systems
>>
>> Suite 7.03
>>
>> 6a Glen St
>>
>> Milsons Point NSW 2061
>>
>> Australia
>>
>> Office: 02 9212 0899
>>
>> Online: 02 8005 0595
>>
>>
>> _______________________________________________
>> Koha-devel mailing list
>> Koha-devel at lists.koha-community.org <mailto:Koha-devel at lists.koha-community.org>
>> https://lists.koha-community.org/cgi-bin/mailman/listinfo/koha-devel
>> website : https://www.koha-community.org/ git :
>> https://git.koha-community.org/ bugs :
>> https://bugs.koha-community.org/
>>
>
> --
> Ere Maijala
> Kansalliskirjasto / The National Library of Finland
> _______________________________________________
> Koha-devel mailing list
> Koha-devel at lists.koha-community.org <mailto:Koha-devel at lists.koha-community.org>
> https://lists.koha-community.org/cgi-bin/mailman/listinfo/koha-devel
> website : https://www.koha-community.org/ git :
> https://git.koha-community.org/ bugs :
> https://bugs.koha-community.org/
>
>
--
Ere Maijala
Kansalliskirjasto / The National Library of Finland
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