This document is intended for use by experienced IT people to be able to configure their COMSOL license servers and license server connections.
For COMSOL to be able to do computations in the Kaleidosim cloud it is essential that the COMSOL UI instance that initiates the simulations on the user’s local computer, and the COMSOL instances doing the simulations in the cloud can reach the same license server.
Your company will require a COMSOL Floating Network License (FNL) to be able to use COMSOL in the cloud. Kaleidosim, on request, can provide a single seat FNL in the cloud that you can use for evaluation purposes. Please note that this will be for a very limited period of hours and Kaleidosim will have to inform COMSOL that such a test is taking place.
Kaleidosim provides a companion app to connect the COMSOL UI to the Kaleidosim cloud called the Kaleidosim cloudCompanion for COMSOL (short: cloudCompanion). The cloudCompanion allows two different types of license server configurations, Direct and Secure.
Direct license server #
The direct connection method is intended to be used for short term, quick, evaluations of the cloudCompanion and the Kaleidosim cloud. If your company is evaluating the cloudCompanion, this is the preferred method to use.
With this method your COMSOL Flexnet license server needs to be accessible both internally on your company network and externally to the internet with a fixed IP address. We suggest placing your license server in your company network demilitarized zone (DMZ) and opening ports to the internet. The default ports that should be opened are 1718 and 1719.
Secure license server #
The secure license server configuration is intended to be used for long term installations when your company is a regular user of COMSOL in the cloud. This configuration allows for Secure Shell (SSH) connections from the Kalediosim cloud machines to access the COMSOL license server via SSH tunneling.
With this option you will upload your public RSA key into the Kaleidosim system, and Kaleidsim will use this key on each of your cloud computation machines to establish an SSH connection to your license server machine.
There are several options for hosting your license server, these are as follows:
Self hosted license server #
You host your own license server in your company’s DMZ. This server will run an SSH server, e.g. openssh-server and it will expose only the SSH server port 22 to the internet. Any port you choose to run this server on is supported if you prefer not to use port 22.
You should add a user to this machine and ensure that the user can set up SSH tunnels for the COMSOL license server you have installed.
The Kaleidosim cloud computation machines will make connections via SSH and connect to the COMSOL license server as required.
Your users will also connect to this server to authenticate the license required for the COMSOL UI running on their machines.
Kaleidosim hosted license server #
Kaleidosim can host your COMSOL license server in our cloud. We will configure a user for you that you can SSH tunnel your COMSOL users into so they can use your COMSOL Network Floating License for your user’s COMSOL UI to authenticate to.
At the time of writing this is currently done using an SSH client to tunnel license server connections to our cloud servers. When the COMSOL UI starts it connects to the tunneled license server instead of a local license server. This can be really useful for businesses with multi-site offices as Kaleidosim simplifies your license server needs by centrally locating the license server for you in the cloud.
Please note that there is a setup cost and a monthly fee associated with this license server hosting. For more details see: https://kaleidosim.com/pricing-kaleidosim-for-comsol/#LicenseServer
Kaleidosim hosted tunnel server #
For high security situations where you wish to keep your COMSOL license server on your own premises, but do not want to use a DMZ machine with open ports on your infrastructure we recommend this option.
Kaleidosim will host a tunnel server for you in our cloud. We will provide you with SSH login RSA certificates for this server. You will establish an SSH tunnel from your local license server yourself to this tunnel server and reverse forward your license server ports from that server to your internal license server. You will need to ensure this tunnel stays alive consistently. For this we recommend the use of a tool such as autossh. See: https://manpages.ubuntu.com/manpages/jammy/man1/autossh.1.html
In this configuration your office based license server will remain as it is, and the Kaleidosim cloud computation machines will connect to the tunnel server for COMSOL license authentication purposes.
This method of setup can be attractive to IT departments because only SSH outbound connections are being made from your network, not open ports are required on your DMZ or internet facing router. Also tunnels can be tightly controlled.
Please note that there is a setup cost and a monthly fee associated with the tunnel server hosting. Due to the low requirements for the tunnel server machines, this will be a very low monthly fee. For more details see: https://kaleidosim.com/pricing-kaleidosim-for-comsol/#TunnelServer
Other options #
If you have other options you would like to explore for license server connections for example VPN or other alternative setups Kaledosim will be happy to support you. Kaleidosim is only able to support license server connections using Linux infrastructure. So VPNs or other connection software has to run on Linux servers.
For related content see: Kaleidosim licenseConnect App: How to Set Up Your System