MATLAB: Is the License Manager using 100% CPU at times

MATLAB

Sometimes the License Manager, specifically the MLM process, is using up 100% of CPU available to it. It can take a few seconds to several minutes. I have a larger Options file, but still within the limits: less than 4000 characters per line, no more than 10,000 lines in total. I have several groups defined according to their IP address with HOST_GROUP and use RESERVE to reserve a certain number seats for different groups.

Clients may get License Manager Error -139 (Timeout) during the high CPU load.

Best Answer

Reserved seats with the RESERVE keyword are computationally expensive when used in combination with IP addresses. When the number of reserved seats for a product and the total number of IP addresses in the Options file reach a certain limit, a license checkout of that product will cause MLM to go to 100% CPU usage.

The more IP addresses are defined in total, the lower the number of reserved seats can be before CPU usage goes up. The duration of high CPU usage seems to depend on the number of reserved seats. It can range from a few seconds when only a few seats over the limit, to several minutes when much over the limit.

Shutting down the license manager will not terminate the overloaded MLM process. You can either wait it out or kill the process manually.

There are no known direct workarounds. The number of reserved seats has to be decreased, at least for the product with the highest number of reserved seats, as that is the most likely culprit. Possibilities include:

- Faster server.

- Use host names or user names instead of IP addresses.

- Use INCLUDE and MAX to implement similar licensing restrictions.

Related Solutions

MATLAB: Do I get the error “Failed to open the TCP port number in the license” when starting the License Manager on Linux

The most common causes of the issues:

1) Port Conflict

2) License Manager restarted too soon after shutdown

To resolve the port conflict issue:

Check whether or not the specified port on the "SERVER" line of the server license file (license.dat) is being by another process.
- For example: SERVER ServerName 0adbdea7de8d 27000
  The Network License Manager is using port 27000.
- You can use the following command to verify the port is not in use:
  "netstat -anp | grep Port#" or "netstat -tulpn | grep port#"
  For example to verify the port "27000" is not in use:
  "netstat -anp | grep 27000" or "netstat -tulpn | grep 27000"
  Any output indicates the port is being used by a different service.
To resolve the issue, you can either change the port number in the server license file or try killing the service running in port 27000.

To resolve the license manager started too soon:

This expected behavior on Linux after stopping the service the port is held for a certain amount of time by the OS.
This is likely to happen if the license manager was shut down using the 'kill -9 lmgrd' command rather than using the 'lmdown' command. In this case, you might have to wait at least 60 seconds from the time when the License Manager is shutdown until restarting. This will allow the OS to recognize that the license server port is available to use.
If you are still unable to restart the license manager, you need to restart the license server.

MATLAB: How to reserve or limit license keys for a group of users on the same subnet

The options file can control seat usage using IP address. You can find out more about options files in the following Article:

Is there a way to administer FLEXnet based licenses? How do I create an Options file?

To to reserve or limit keys for IP addresses or a specific subnet, you can use the INTERNET option. Below are some examples.

To reserve 5 keys of MATLAB for users on the subnet 177.35.40.*:

RESERVE 5 MATLAB INTERNET 177.35.40.*

To reserve 2 keys of Simulink for users on the subnet 177.35.41.*:

RESERVE 2 Simulink INTERNET 177.35.41.*

To limit the number of keys of MATLAB to 3 for users on subnet 179.37.64.*:

MAX 3 MATLAB INTERNET 179.37.64.*

To limit the number of keys of Simulink to 1 for users on subnet 179.37.62.*:

MAX 1 Simulink INTERNET 179.37.62.*

There is no way to set up a group of subnets to reserve or limit license keys. For example, the following is NOT possible:

MAX 3 MATLAB INTERNET 179.56.85.* 179.56.84.*

The only workaround for this is to use hostnames or individual IP Addresses. You can set up a HOST_GROUP with a list of all of the hostnames or specific IP Addresses you wish to reserve or limit the license keys for:

HOST_GROUP group_name host1 host2 host2...

Then, use this in your RESERVE or MAX line:

RESERVE 5 MATLAB HOST_GROUP group_name
MAX 3 Simulink HOST_GROUP group_name

Best Answer

Related Solutions

MATLAB: Do I get the error “Failed to open the TCP port number in the license” when starting the License Manager on Linux

MATLAB: How to reserve or limit license keys for a group of users on the same subnet

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