java performance versus python, cheaper?

[Gitted]

I am assuming that the performance of a java app on appengine would
outperform a python application, would this actually result in cheaper
hosting fees?

Are both platforms just as stable?

(let's ignore the fact that you can probably develop faster with
python)

[D X]

I don't know of any measure of stability.

I do see more Java complaints on the mailing list, but it might just be that there are more Java users.

Performance would vary depending on your app.  I assume Java would have a perf advantage on a processing intensive app, though, for example, if your app is bottlenecked by datastore queries, that might significantly reduce the Java advantage.

[Jeff Schnitzer]

On Thu, May 24, 2012 at 10:54 AM, Gitted <sahme...@gmail.com> wrote:
> I am assuming that the performance of a java app on appengine would
> outperform a python application, would this actually result in cheaper
> hosting fees?

I think it's fairly safe to say that if instance hours represents a
significant part of your expense (as opposed to datastore ops or
storage), Java will save you some bucks. It's hard to predict how
much - it will depend heavily on your app. The key differentiator is
that Java's serialization and garbage collection are significantly
faster than Python's, and GAE service calls require a lot of both.

No, I haven't run apples-to-apples benchmarks... but issues like
http://code.google.com/p/appengine-ndb-experiment/issues/detail?id=118
give me cause for concern. FWIW, I develop GAE apps in both Python
and Java, and like both environments for different kinds of projects.

Jeff

[Brandon Wirtz]

Actually, since so much of App Engine Apps tend to be dependent on
API's, the Language doesn't make much difference in cost. A DataStore
Read or Write is the same cost in either. New instances seem to spin
up faster (for me) in python than Java, which gets you a small
savings. Java has better multi-threading compared to python 2.7, but
it seems to me that for some reason Python takes better advantage of
larger instances.

Look at what you want to do, if you need a frame work, and how many
dev resources you will spend in each.