Question

I figure by the use cases node is designed for that it would have much less overhead than python would when starting up. But can anyone confirm this by way of experience or benchmarks.

The reason I ask is I’m working on a project in which we are starting many, ~20, python scripts every minute. In these processes we are doing tons of IO with databases and the network. This is a place node would shine, so I want to explore the benefits of possibly using node over python here. I know I could use twisted here to do my i/o asynchronously, but I still need to start these processes up every minute.

Edit:

I know that its not always seen as ideal to start processes like described here. But in this architecture for this system this is the ideal solution. This is why I consider node. Because V8 is event driven only, calling “node myscript.js” at a rate of 20/min shouldn’t matter. Calling myscript.js IS the event. Its just not in the browser anymore. [edit] Totally Wrong

After driving to work and thinking about this, I guess my question should have been about how best to benchmark code. From there I could profile both designs.

Update:

brandizzi showed me my err. Doing ‘node myscript.js’ is NOT the event. And in the end, the node interpreter does take a little longer to start than python. However, that amount is pretty much nothing.

Answer 1

Your question is too vague IMHO. Anyway, if you want to compare the startup time, why not just time? Look at some examples of it (the files null.* are empty since we are trying to measure the boot time only):

$ i=0
$ time while [ $((i++)) -lt 1000 ] ; do python null.py ; done

real    0m55.777s
user    0m30.154s
sys 0m13.910s

$ i=0
$ time while [ $((i++)) -lt 1000 ] ; do node null.js ; done

real    1m37.618s
user    0m59.578s
sys 0m18.038s

These preliminary results indicate that node is somewhat slower to boot up. (Your statement that “Calling myscript.js IS the event” does not look true to me and my suspicion seems confirmed. myscript.js invocation is an event – but calling it with node myscript.js loads an entire process to just treat this event.)

To be honest, however, the vagueness of your question makes me wonder if you are not trying some time of premature optimization – in other words, it looks like you not even has a problem to be solved yet! I can be wrong, of course, but maybe you do not need to worry about this question for now (even because I started one thousand processes of each interpreter in more or less one minute – if you will start just twenty the start up of the interpreter may be no problem.)

Anyway, my pythonista side would make some suggestions. For example: how much time the processes take to finish? If it is a short time, you really can think about using the Poll of the multiprocessing module, which would create a poll of processes for managing your requirements. Even you you want to invoke your scripts through some kind of shell script (because there is no much difference between in invoking them through a Bash script or the multiprocessing module anyway), I bet Python has the advantage of generating a bytecode .pyc file. Does V8 do it too?