These are chat archives for ipython/ipython

23rd
Oct 2018
jagan96
@jagan96
Oct 23 2018 12:24
hello all, when i start the ipcontroller and engines and use the async call to perform a function on a chunk, will i need to shutdown the engines and restart for each chunk
one more doubt is when the engines are processing a chunk, some engines are becoming idle until all other engines complete the execution.So, there is some time wasting as the engines are becoming idle and is there any way to minimize the wait time by the engines.
@minrk
Min RK
@minrk
Oct 23 2018 12:27
Engines can process many tasks during their lifetime. You generally shouldn't need to restart them.
Engines becoming idle is totally up to the work you assign them.
If you are using load-balanced scheduler, the way to ensure maximum fairness at the expense of some latency for small tasks is to set c.TaskScheduler.hwm=1. This is the default. This ensures that only one task can be assigned to each node at a time, so no engine should be idle unless all of your tasks are being worked on.
jagan96
@jagan96
Oct 23 2018 12:36
okay..so by default there will be fair distribution of the chunk between all the engines so that the idle time of the engines once their work is done is minimum. right?
Min RK
@minrk
Oct 23 2018 12:37
Assuming tasks are relatively small, yes
e.g. if each task takes 1 minute and you have 8 engines, 8 tasks will take 1 minute, while 9 tasks will take 2 minutes with only one engine working on a second task while the other 7 are idle.
jagan96
@jagan96
Oct 23 2018 13:19

hi ,
Our setup is as follows:
4 remote machines running 128 engines and 1 machine running the controller
We are using the default profile without any modification
Credentials files are shared through share drive.

We are able to process our requests completely without any issue.
However, once all the requests are processed and engines remain idle for about 1 hr,
we are not able to process our requests without restarting the ip controller and engines.
In jupyter notebook it hungs at the cell where import of libraries are done.

@minrk