Comment 1 Samuel Mannehed 2022-03-09 17:06:12 CET

This doesn't necessarily have to be done using tlwebadm. A tool like tlctl could also be used for something like this.

Comment 2 Samuel Mannehed 2022-03-09 17:11:00 CET

A use case for this is if the admin wants to slowly start emptying an agent before doing upgrades or other changes to the host.

Stopping the 'vsmagent' service would result in the master thinking the agent is down. This, in turn, would when reconnecting to sessions on this agent cause the user to be prompted to abandon the session.

Removing the agent from the configuration will probably achieve the wanted result, but might feel too "permanent" to the admin. The practice of doing this for this use case was documented in bug 7610.

Comment 6 Samuel Mannehed 2025-05-02 16:15:55 CEST

> MUST
> * The draining mode for agents implemented in bug 8545 must be configurable from Web Admin.
Yes. A section for draining has now been added on the Cluster/Agents page. It has toggle-switches for enabling draining on each agent row.

> SHOULD
> * The visual representation should be easy to understand without any documentation.
Hopefully, the toggle-switches are self-explanatory. There is a short description above the table as well.

> COULD
> * Documentation for the topic of stopping session creation on an agent could mention the possibility of doing this in Web Admin.
Yep, it is now mentioned.

I also considered adding a column for "Users" in the draining-table. But after internal discussions, we decided against it. It is better if the Cluster/Agents page is about configuration, and then the admin should check the Status/Load or Status/Sessions pages for status on how things are going.

Comment 7 Samuel Mannehed 2025-05-02 16:18:28 CEST

(In reply to Samuel Mannehed from comment #1)
> This doesn't necessarily have to be done using tlwebadm. A tool like tlctl
> could also be used for something like this.
It was only added to Web Admin. Command-line users can enable draining using tl-config:

 $ sudo tl-config /agents/draining=agent1.example.com

Comment 8 Tobias 2025-05-06 08:37:59 CEST

Tested this bug using server build #4037 on RHEL9 and client version
4.18.0 on Fedora41, and visited tlwebadm using Firefox138 on Fedora41.

When toggling an agent to be draining, it is indeed reflected by the
hiveconf, and a vsmserver restart was confirmed to be required for the
setting to take effect.

Verified that in a cluster with several agents, sessions won’t start on
draining agents, but rather solely on nondraining agents.

Moreover, confirmed that active sessions on draining agents are allowed
to be reconnected to, and will be prioritized in a cluster over
nondraining agents.

Having enabled multisession while draining an agent with active
sessions, no issues were encountered as new sessions started on
nondraining agents.

Had a look at the related documentation, which appears to properly
convey the feature in question.

> MUST
> * The draining mode for agents implemented in bug 8545 must be configurable from Web Admin.
✅ It is. Draining can be toggled on and off in tlwebadm.
> SHOULD
> * The visual representation should be easy to understand without any documentation.
✅ There is little room for misunderstandings with the toggle button.
> COULD
> * Documentation for the topic of stopping session creation on an agent could mention the possibility of doing this\
 in Web Admin.
✅  Web admin is mentioned as an alternative path.

Things are generally in order and the acceptance criteria are
fulfilled. Toggling draining on and off for agents appears to be working
as intended using Web Admin.

My only concern is that with the multiple save buttons on the
Cluster/Agents page we deviate from the format we see e.g. on the
Profiles/Introduction texts page, where only one button is used for
several subsections.

Comment 9 Tobias 2025-05-06 12:39:09 CEST

(In reply to Tobias from comment #8)
> My only concern is that with the multiple save buttons on the
> Cluster/Agents page we deviate from the format we see e.g. on the
> Profiles/Introduction texts page, where only one button is used for
> several subsections.

A separate bug (bug 8582) was created on this topic, that tlwebadm pages are a bit inconsistent in how they save new settings.

With that in place, we are ready to close this bug.