ULimit problem

RichP1

Hi all,

We're running Lightstreamer Server on Linux. In the LS.sh file there are the following commands:

ulimit -Hn unlimited
ulimit -Sn unlimited

We're having trouble getting these commands to run correctly. We can set the lower limit, but not the higher limit - we keep getting an 'Operation not permitted' error. We suspect it's a Linux issue, but I was wondering if you've come across this before and know how to resolve it?

As a separate question, why does Lightstreamer need to modify the limit settings? What are the consequences of not changing these?

Thanks,

Richard

Dario Crivelli

The limit on the number of open files in Unix and Linux also applies to the number of open sockets. Hence, in a production installation of Lightstreamer Server, you must take this limit under control.
We choose to put the "ulimit" command in the Server launch script as a memo for this issue, even though it might not work in some environments. For testing purpose, you can ignore the issue.

Dario

juls

We have purchased Allegro licenses and are attempting to set up Lightstreamer in a production environment.

We are receiving the same "ulimit: open files: cannot modify limit: Operation not permitted" error while trying to run the LS.sh file.

We seem to be unable to set the values to unlimited.
How should we determine adequate values for the -Hn and -Sn limits?

Thanks

Alessandro Alinone

As explained previously, these ulimit settings are just a memo for the system administrator of the box running Lightstreamer. She should know what is the default limit on the number of TCP sockets (file descriptors) imposed by that particular Unix/Linux installation. Then, if such number is not enough to handle the desired number of concurrent connections [as a rule of thumb, double the number of maximum number of expected concurrent users to estimate the needed file descriptors], she should change some operating system setting to increase such number. The ulimit commands are just a typical way of doing this, which is very system dependent.

I hope that helps.