[Python-Dev] To reduce Python "application" startup time

[Wes Turner]

On Wednesday, September 6, 2017, INADA Naoki <songofacandy at gmail.com> wrote:

> > How significant is application startup time to something that uses
> > Jinja2? Are there short-lived programs that use it? Python startup
> > time matters enormously to command-line tools like Mercurial, but far
> > less to something that's designed to start up and then keep running
> > (eg a web app, which is where Jinja is most used).
>
> Since Jinja2 is very popular template engine, it is used by CLI tools
> like ansible.


SaltStack uses Jinja2. It really is a good idea to regularly restart the
minion processes.

Celery can also cycle through worker processes, IIRC.


>
> Additionally, faster startup time (and smaller memory footprint) is good
> for even Web applications.
> For example, CGI is still comfortable tool sometimes.
> Another example is GAE/Python.


Short-lived processes are sometimes preferable from a security standpoint.
Python is currently less viable for CGI use than other scripting languages
due to startup time.

Resource leaks (e.g. memory, file handles, database references; valgrind)
do not last w/ short-lived CGI processes. If there's ASLR, that's also
harder.

Scale up operations with e.g. IaaS platforms like Kubernetes and PaaS
platforms like AppScale all incur Python startup time on a regular basis.


>
> Anyway, I think researching import tree of popular library is good
> startline
> about optimizing startup time.
> For example, modules like ast and tokenize are imported often than I
> thought.
>
> Jinja2 is one of libraries I often use. I'm checking other libraries
> like requests.


> Thanks,
>
> INADA Naoki  <songofacandy at gmail.com <javascript:;>>
> _______________________________________________
> Python-Dev mailing list
> Python-Dev at python.org <javascript:;>
> https://mail.python.org/mailman/listinfo/python-dev
> Unsubscribe: https://mail.python.org/mailman/options/python-dev/
> wes.turner%40gmail.com
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-dev/attachments/20170906/0e75667c/attachment-0001.html>