Why do I see the error message "WARNING: The mjsscript detected that the number of processes allowed is limited by ulimit" when starting the mjs service on Linux?

Why do I see the error message "WARNING: The mjs script detected that the number of processes allowed is limited by ulimit" when starting the mjs service on Linux?

Answer 1

[MathWorks Support Team]

The mjs service will issue this warning if the result of "ulimit -u" is not 'unlimited'. This command measures the number of processes or threads a user can launch on the machine. Depending on the value of "ulimit -u" the number of processes available may be too low to run your desired number of workers on a single machine.

An estimate of the number of processes needed on a machine is

128 *nW 

(where nW is the number of workers you wish to run on the machine). If your limit is lower than the estimate then you may wish to adjust the process limit up, this may need assistance from your Linux administrator.

Information on ulimit recommendations and ways to save the settings are available here: 

http://www.mathworks.com/help/parallel-computing/recommended-system-limits-for-macintosh-and-linux.html

Note: prior to R2019b the mjs service was known as mdce and MATLAB Parallel Server was known as MATLAB Distributed Computing Server.