Docker and Kubernetes FAQ

Can I install Sametime 11.5 Meetings on the Community Server?

In a proof-of-concept environment, if you have Docker on the same host, then you can run meetings on it. For production workloads, HCL support recommends separating the Meetings and Community servers onto separate hosts.

Which do I need, Docker or Kubernetes? Is one better than the other?

Docker and Kubernetes have different goals and outcomes. The decision should depend on your end goal. Docker is about containerization; Kubernetes is about container orchestration. The Docker containers are the building blocks. A small deployment has the bare minimum number of containers to produce a solution that allows users to collaborate, but without scalability, load balancing, etc. If you are deploying for a small group and do not require scalability, Docker is a simple solution. Kubernetes builds on the base containers and allows them to auto scale; load balance across multiple physical or virtual hosts, even bringing up and tearing down new hosts to deal with load variance.

Meetings are sized based upon what is happening on the server at any given time. There are many variables including the size (CPU and Memory) of the Docker instance. A large Docker instance can support up to 200 concurrent peak users, but that does not take into consideration how many of the meetings are being recorded. Meeting recordings are CPU intensive. A Docker instance can only record up to 2 meetings simultaneously. Its best suited for a small department or focused team than an enterprise size deployment.

Kubernetes overcomes these limitations by autoscaling. Autoscaling adds and removes nodes as needed based upon current usage and monitoring. Kubernetes is recommended if you are deploying Sametime meetings for your entire organization.

For sizing and deployment related questions, contact HCL.

Do Sametime 11.5 Meetings support high availability?

High availability is supported for the front-end web traffic to the Kubernetes cluster. You can deploy multiple web front ends on different physical/virtual nodes pointing to the same back end in order to both distribute load and survive a node outage.

High availability is not supported for active meetings. If a server hosting a meeting goes down, users in meetings on that server will be interrupted. There is a reconnection timer built into the client which will cause all the clients to re-connect and be distributed to another available node. In some circumstances, a server going down will result in the client thinking the meeting has ended. Users can quickly re-join the meeting from their "recent meetings" list and will be meeting again on an available server momentarily.

What is the maximum number of participants in a meeting?

The default setting is 25 users. Currently, the maximum supported number of users per meeting is 50. To change the setting, see: Configuring the maximum number of meeting occupants.

How many concurrent users does the Sametime 11.5 meeting server support?

This depends on the size of the deployment. For sizing and deployment related questions, contact HCL.

The Sametime meeting server supports both Docker and Kubernetes, what level of help with these technologies can I expect to receive from HCL technical support?

Docker and Kubernetes are third party products. HCL support is available to assist in configuration and support related issues as it pertains to the Sametime product. If you require assistance with a full Kubernetes or Docker deployment, please reach out to HCL Services or one of our HCL Business Partners to inquire about professional services.

What are the system requirements?

Docker on Linux is the supported and recommended platform. Red Hat Enterprise Linux and CentOS have been tested. For more information on system requirements, see HCL Sametime 11.5 and HCL Sametime Meetings 11.5 System Requirements.

How do I migrate from different versions of Docker/Kubernetes when moving servers?

When moving to a new server, redeploy Sametime Meetings as a new configuration. If the server hostname in the URL changes, you can push the new URL to the users using Managed Settings. Existing meeting URLs should work if the hostname remains the same.

Will supported packages for Kubernetes and Docker be available on the HCL License and Delivery Portal?

No, packages for Kubernetes and Docker can be downloaded directly from your vendor.

How do we backup and restore Docker/Kubernetes?

The backup and restore process is handled by Docker and Kubernetes, it is handled outside of Sametime. Consult with your Docker or Kubernetes vendor for details.

Is clustering automatic for Kubernetes?

Yes, but there is additional configuration required in a Kubernetes environment.

Is the Media Server separate from Sametime 11.5 Meetings?

The video bridge is part of the meeting server, there are no additional Sametime components for meetings.

Can I deploy Sametime Meetings in a Kubernetes Cloud?

Yes, HCL has published a guide to deploying Sametime Meetings in Amazon's AWS Elastic Kubernetes Services. There will be similar guides published for other cloud providers. This page will be updated as these guides become available.