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cli: add command 'kallithea-cli front-end-build'
Kallithea is under the GPL license, and we can thus only distribute any
generated code if we also ship the corresponding source.
We are moving towards a web front-end that use npm to download and compile
various open source components. The components might not be GPL, but if we
distribute any parts of their code (compiled or converted to other
representation), then we also must distribute the corresponding source under
the GPL.
It doesn't seem feasible for us to distribute the source of everything that
npm downloads and includes when we are building. It thus also doesn't seem
feasible for us to build and ship the compiled (possibly minified) front-end
code. Instead, we have to make it as smooth as possible for our users to
get up and running.
It doesn't seem feasible for us to ship or install npm. We must assume it is
available. That requirement must be documented clearly, and we must recommend
how to install npm for the most common platforms.
We could perhaps just document what manual steps to run. Kallithea doesn't
work out of the box anyway - it has to be configured and initialized. Extra
steps might not be a big problem.
Another approach is to call out to npm while pip is installing Kallithea and
download the requirements and build the files. It can be done by customizing
setuptools commands in setup.py. But: Python packaging is fragile. Even
though we only support pip, it really isn't built for things like this.
Custom output is muted and buffered and only shown if running with -v or the
command fails. And pip and setup.py can be used to build and install in so
many ways that we probably can't make it work reliably with all ways of
installing Kallithea.
The approach implemented by this commit is to add a custom cli command
'front-end-build' to run the required commands. This single user-facing
command can internally run various steps as needed. The only current
requirement is the presence of npm and an internet connection.
For now, this will just create/update style.css ... but currently probably
without any actual changes. The files created by npm (and the node_modules
directory) must *not* be a part of the release package made with 'setup.py
sdist'.
(Commit message is mostly written by Mads Kiilerich)
Kallithea is under the GPL license, and we can thus only distribute any
generated code if we also ship the corresponding source.
We are moving towards a web front-end that use npm to download and compile
various open source components. The components might not be GPL, but if we
distribute any parts of their code (compiled or converted to other
representation), then we also must distribute the corresponding source under
the GPL.
It doesn't seem feasible for us to distribute the source of everything that
npm downloads and includes when we are building. It thus also doesn't seem
feasible for us to build and ship the compiled (possibly minified) front-end
code. Instead, we have to make it as smooth as possible for our users to
get up and running.
It doesn't seem feasible for us to ship or install npm. We must assume it is
available. That requirement must be documented clearly, and we must recommend
how to install npm for the most common platforms.
We could perhaps just document what manual steps to run. Kallithea doesn't
work out of the box anyway - it has to be configured and initialized. Extra
steps might not be a big problem.
Another approach is to call out to npm while pip is installing Kallithea and
download the requirements and build the files. It can be done by customizing
setuptools commands in setup.py. But: Python packaging is fragile. Even
though we only support pip, it really isn't built for things like this.
Custom output is muted and buffered and only shown if running with -v or the
command fails. And pip and setup.py can be used to build and install in so
many ways that we probably can't make it work reliably with all ways of
installing Kallithea.
The approach implemented by this commit is to add a custom cli command
'front-end-build' to run the required commands. This single user-facing
command can internally run various steps as needed. The only current
requirement is the presence of npm and an internet connection.
For now, this will just create/update style.css ... but currently probably
without any actual changes. The files created by npm (and the node_modules
directory) must *not* be a part of the release package made with 'setup.py
sdist'.
(Commit message is mostly written by Mads Kiilerich)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 | .. _performance:
================================
Optimizing Kallithea performance
================================
When serving a large amount of big repositories, Kallithea can start performing
slower than expected. Because of the demanding nature of handling large amounts
of data from version control systems, here are some tips on how to get the best
performance.
Fast storage
------------
Kallithea is often I/O bound, and hence a fast disk (SSD/SAN) and plenty of RAM
is usually more important than a fast CPU.
Caching
-------
Tweak beaker cache settings in the ini file. The actual effect of that is
questionable.
Database
--------
SQLite is a good option when having a small load on the system. But due to
locking issues with SQLite, it is not recommended to use it for larger
deployments.
Switching to MySQL or PostgreSQL will result in an immediate performance
increase. A tool like SQLAlchemyGrate_ can be used for migrating to another
database platform.
Horizontal scaling
------------------
Scaling horizontally means running several Kallithea instances and let them
share the load. That can give huge performance benefits when dealing with large
amounts of traffic (many users, CI servers, etc.). Kallithea can be scaled
horizontally on one (recommended) or multiple machines.
It is generally possible to run WSGI applications multithreaded, so that
several HTTP requests are served from the same Python process at once. That can
in principle give better utilization of internal caches and less process
overhead.
One danger of running multithreaded is that program execution becomes much more
complex; programs must be written to consider all combinations of events and
problems might depend on timing and be impossible to reproduce.
Kallithea can't promise to be thread-safe, just like the embedded Mercurial
backend doesn't make any strong promises when used as Kallithea uses it.
Instead, we recommend scaling by using multiple server processes.
Web servers with multiple worker processes (such as ``mod_wsgi`` with the
``WSGIDaemonProcess`` ``processes`` parameter) will work out of the box.
In order to scale horizontally on multiple machines, you need to do the
following:
- Each instance's ``data`` storage needs to be configured to be stored on a
shared disk storage, preferably together with repositories. This ``data``
dir contains template caches, sessions, whoosh index and is used for
task locking (so it is safe across multiple instances). Set the
``cache_dir``, ``index_dir``, ``beaker.cache.data_dir``, ``beaker.cache.lock_dir``
variables in each .ini file to a shared location across Kallithea instances
- If using several Celery instances,
the message broker should be common to all of them (e.g., one
shared RabbitMQ server)
- Load balance using round robin or IP hash, recommended is writing LB rules
that will separate regular user traffic from automated processes like CI
servers or build bots.
Serve static files directly from the web server
-----------------------------------------------
With the default ``static_files`` ini setting, the Kallithea WSGI application
will take care of serving the static files from ``kallithea/public/`` at the
root of the application URL.
The actual serving of the static files is very fast and unlikely to be a
problem in a Kallithea setup - the responses generated by Kallithea from
database and repository content will take significantly more time and
resources.
To serve static files from the web server, use something like this Apache config
snippet::
Alias /images/ /srv/kallithea/kallithea/kallithea/public/images/
Alias /css/ /srv/kallithea/kallithea/kallithea/public/css/
Alias /js/ /srv/kallithea/kallithea/kallithea/public/js/
Alias /codemirror/ /srv/kallithea/kallithea/kallithea/public/codemirror/
Alias /fontello/ /srv/kallithea/kallithea/kallithea/public/fontello/
Then disable serving of static files in the ``.ini`` ``app:main`` section::
static_files = false
If using Kallithea installed as a package, you should be able to find the files
under ``site-packages/kallithea``, either in your Python installation or in your
virtualenv. When upgrading, make sure to update the web server configuration
too if necessary.
It might also be possible to improve performance by configuring the web server
to compress responses (served from static files or generated by Kallithea) when
serving them. That might also imply buffering of responses - that is more
likely to be a problem; large responses (clones or pulls) will have to be fully
processed and spooled to disk or memory before the client will see any
response. See the documentation for your web server.
.. _SQLAlchemyGrate: https://github.com/shazow/sqlalchemygrate
|