Ponos – A simple yet powerful load generator in Erlang

https://github.com/klarna/ponos

by lelf • 12 years ago

24 20 12 years ago

github.com

ivanche• 12 years ago

Just a comment on name - in Serbian "ponos" means "pride". So I guess author should be proud of his work :)

kovrik• 12 years ago

And in Russian "ponos" means "diarrhea" :(

jool6• 12 years ago

Something the author (me) is aware of. See the Notes section of the README (https://github.com/klarna/ponos#ref1).

The original name is based on the Greek god of hard labor and toil (http://en.wikipedia.org/wiki/Ponos).

danatkinson2• 12 years ago

I think it's probably from Greek mythology. Ponos was the God of hard labour - https://en.wikipedia.org/wiki/Ponos

danatkinson2• 12 years ago

Actually, it is. It's in the readme on the first line! :)

hymloth• 12 years ago

Ponos in modern Greek means "pain".

rdtsc• 12 years ago

To continue with the languages pun, in Russian it means something like "diarrhea", which, strangely also kind of makes sense, ... in a toilet humor kind of disgusting way.

I think it is a good name.

To add though, this is a cool idea. I like it generates an internal-kind of load. Not necessarily driven from external requests. So this combined with tsung to test how the system behaves in various scenarios.

Operating under load is not something many people test. Search Erlang Factor talks and you'll find many talks by Erlang experts on load monitoring, load shedding and so on basically characterizing behaviour during overload conditions.

valanto• 12 years ago

Ponos in grid besides being the god of Hard Labour also means pain itself in modern greek

jtmoulia4• 12 years ago

I'd love to use this to test my application, but after reading through the docs, I'm not quite sure how to get the setup I'd like:

My application is a server which clients login and then issue commands to. As I'm imagining it, a user load generator would be creating and logging in users. But this is where I get fuzzy... should the user task also create a load generator which issues commands against the application as that user? Seems pretty simple, hopefully it's possible !

Excited to try this out.

jool6• 12 years ago

Where ponos is at currently its main purpose in the world is specialise in generating simple or complex load patterns.

A load_generator in essence is just a process generating triggers at requested frequency. Every trigger happens asynchronously so there is no way to thread state between triggers.

If there is enough interest I'd be happy to extend it to handle synchronous load generators where threading state makes sense. With that use case though, it'd be impossible to guarantee that the actual load matches the load_spec in all circumstances.

If you wish to keep state between triggers you have to implement this outside of ponos at this stage.

jool6• 12 years ago

For your particular use case though I'd just login and pass the user information as part of the task. The load_generator would then not be concerned about logging in but only issuing commands.

jtmoulia4• 12 years ago

Thanks for the explanation!

Not the most flexible solution, but if you want the load spec to be authoritative you could allow it to recursively specify a different load generator rather than a task_runner. Instead of running a task, it would start a new load generator.

... hope I got some of the terminology right.

odo2• 12 years ago

I am also interested in load testing stateful sessions e.g. log in, wait, do stuff, wait, log out. Using ponos this could be done by spawning a (gen_server-) process in the task which runs the session and then terminates. In this scenario the load function would model the arrival rate of the users.

LLWM• 12 years ago

Put your.. that! Y.. your load generator! To my.. my... HERE! My application! And j.. j.. JAM IT IN!

Ponos – A simple yet powerful load generator in Erlang

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