Guys, I'm not saying that the director is bad or wrong, actually what I
want is maybe to improve it a little bit without touching the logic or the
api, my final goal is maybe to create a drop in replacement but keeping the
agent and the logic in place. I know it can be hard work but OTP solves a
lot of "edge cases" of the classic languages out of the box.
Geoff by downtime I mean that, no matter what, in languages like
ruby/python/go or any "classical" language you need to stop and start again
the server to read the new code while in erlang / elixir there is no need
for this,since it has a feature that it is called "hot code reloading" (You
can read about it here
<
http://learnyousomeerlang.com/designing-a-concurrent-application#hot-code-loving>,
here <
http://erlang.org/doc/man/code.html> and here
<
http://www.unstablebuild.com/2016/03/18/hot-code-reload-in-elixir.html>)
it is one of the moto's of erlang 99.9999999% (nine nines of availability)
and you can read more here <
https://pragprog.com/articles/erlang>.
Marco good catch and thanks for the suggestion for the license, maybe I'll
evaluate some others like Apache or LGPL.
Thanks,
Leandro.-
2017-04-27 20:26 GMT+02:00 Voelz, Marco <marco.voelz(a)sap.com>:
Dear Leandro,
I'd love to see your experiment grow – keep in mind that the Director is
around for quite a while and has some pretty complicated corner cases. Just
like any rewrite: It is pretty simple to get 80% right, but then you'll
spend much time on getting the remaining 20%.
A word on the license: If your target audience is really companies like
IBM, don't go with GPL. I now that for example GPL is a no-go for us at
SAP. I would assume a similar policy is in place in pretty much every big
enterprise.
Warm regards
Marco
*From: *Leandro David Cacciagioni <leandro.21.2008(a)gmail.com>
*Reply-To: *"Discussions about the Cloud Foundry BOSH project." <
cf-bosh(a)lists.cloudfoundry.org>
*Date: *Thursday, 27. April 2017 at 19:57
*To: *"Discussions about the Cloud Foundry BOSH project." <
cf-bosh(a)lists.cloudfoundry.org>
*Subject: *[cf-bosh] Re: Re: Elixir for bosh director?
OK what you quote is certainly amazing, anyway that only tackle the
Scalability in part (I know for sure that elixir/erlang can hold the same
a lot better) but it didn't solve the Fault Tolerance part or the true no
downtime deployments (I know that people like IBM will love to update BOSH
with true / zero downtime). Plus all the simplification in the Director
logic that can come from using the proper tool for the right job. Anyway I
think I'll start a POC as under GPL license to make a compatible "BOSH
director" using elixir. Anyone who will like to help more than welcomed.
2017-04-27 17:59 GMT+02:00 Geoff Franks <geoff(a)starkandwayne.com>:
FWIW, we've managed BOSHes with many deployments, some of which consist of
~1000 VMs, and not seen any direct performance issues of the BOSH director.
Just lengthy deploys due to having so many VMs to iterate through.
I've also seen a significant uptick in responsiveness from the bosh cli
when using the v2 cli, since ruby isn't parsing for tons of gemfiles every
time I start the CLI up.
On Apr 27, 2017, at 9:01 AM, Leandro David Cacciagioni <
leandro.21.2008(a)gmail.com> wrote:
After more than 6 months working with elixir in prod, it crossed my mind
that maybe it deserves some time of experiment and think on the possibility
of a *TOTAL REWRITE OF BOSH DIRECTOR USING ELIXIR*.
Some of the pros that I can list out of the box (without digging to much
in the technical side) are:
· Ruby like syntax (I know I know... This means a lot for people
that don't like erlang syntax) (I'm used to both so far)
· Easiness of development thanks to OTP & FP.
o Scalability (ex: http://www.phoenixframework.org/blog/the-road-to-2-
million-websocket-connections)
o Fault-tolerance
o True no downtime updates.
· Simplification:
o nats can be deprecated.
o All the other jobs (Director, Registry, Blobstore, HM & CPI) can to
be OTP/Apps (Mix powered) under the same umbrella project.
o Clustering out of the box
· Perfomance wins, giving the nature of elixir/erlang/OTP is easy
to guess that a single bosh instance will gonna be able to manage more
deployments and bigger deployments than it does now.
This is a suggestion and I would like to know if you agree or don't and
why.
Thanks,
Leandro.-
