Editing CommunityData:Hyak

From CommunityData
Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.

The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then publish the changes below to finish undoing the edit.

Latest revision Your text
Line 131: Line 131:
The Slurm scheduler provides a command called [https://slurm.schedmd.com/scancel.html scancel] to terminate jobs. For example, you might run <tt>queue_state</tt> from a login node to figure out the ID number for your job (let's say it's 12345), then run <tt>scancel --signal=TERM 12345</tt> to send a SIGTERM signal or <tt>scancel --signal=KILL 12345</tt> to send a SIGKILL signal that will bring job 12345 to an end.
The Slurm scheduler provides a command called [https://slurm.schedmd.com/scancel.html scancel] to terminate jobs. For example, you might run <tt>queue_state</tt> from a login node to figure out the ID number for your job (let's say it's 12345), then run <tt>scancel --signal=TERM 12345</tt> to send a SIGTERM signal or <tt>scancel --signal=KILL 12345</tt> to send a SIGKILL signal that will bring job 12345 to an end.


=== Parallelization Tips ===
=== Parallel R ===


The nodes on Mox have 28 CPU cores. Our nodes on Klone have 40.  These may help in speeding up your analysis ''significantly''. If you are using R functions such as <code>lapply</code>, there are parallelized equivalents (e.g. <code>mclappy</code>) which can take advantage of all the cores and give you a 2800% or (4000)% boost! However, something to be aware of here is your code's memory requirement—if you are running 28 processes in parallel, your memory needs can also go up to 28x, which may be more than the ~200GB that the <code>big_machine</code> node on mox will have. In such cases, you may want to dial down the number of CPU cores being used—a way to do that globally in your code is to run the following snippet of code before calling any of the parallelized functions.
The nodes on Hyak have 28 CPU cores. These may help in speeding up your analysis ''significantly''. If you are using R functions such as <code>lapply</code>, there are parallelized equivalents (e.g. <code>mclappy</code>) which can take advantage of all the cores and give you a 2800% boost! However, something to be aware of here is your code's memory requirement—if you are running 28 processes in parallel, your memory needs can also go up to 28x, which may be more than the ~200GB that the <code>big_machine</code> node will have. In such cases, you may want to dial down the number of CPU cores being used—a way to do that globally in your code is to run the following snippet of code before calling any of the parallelized functions.
 
If you find yourself doing this often, consider if it is possible to reduce your memory usage via streaming, databases (like sqlite; parquet files; or duckdb), or lower-precision data types (i.e., use 32bit or even 16bit floating point numbers instead of the standard 64bit).  


<source lang="r">
<source lang="r">
Please note that all contributions to CommunityData are considered to be released under the Attribution-Share Alike 3.0 Unported (see CommunityData:Copyrights for details). If you do not want your writing to be edited mercilessly and redistributed at will, then do not submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource. Do not submit copyrighted work without permission!

To protect the wiki against automated edit spam, we kindly ask you to solve the following CAPTCHA:

Cancel Editing help (opens in new window)

Templates used on this page: