Converting a community to a space fails when containing many users

[markvoortman]

Steps to reproduce

1. Whenever I try to convert a community to a space it fails when it contains many (~75) users.
2. Go to Settings > Preferences > Show my Communities > Create Space.
3. It then fails to complete that action, for a screen shot see the "what happened" section.
4. I also tried the desktop app (in addition to the web app) but that didn't make a difference.

Note: it did work for communities with only a few or no users.

What happened?

What did you expect?

I expected the community to be converted to a space.

What happened?

It failed and asked me to retry (which also didn't work).
On the web console this error was visible:

Operating system

No response

Browser information

No response

URL for webapp

No response

Homeserver

No response

Have you submitted a rageshake?

No

[t3chguy]

I don't think the spec defines a limit on how many users you can invite at once, so this is a pesky Synapse implementation detail which the client has no way of getting at.

Looking at the Synapse implementation, it depends on the homeserver.yaml configuration and also can be set per-user. The Server does not tell the client what the limit is.

[novocaine]

Can we increase it for matrix.org, which is where I think this bug is filed for?

[t3chguy]

Can we increase it for matrix.org, which is where I think this bug is filed for?

I guess this would be an Ops question, maybe with some Moderation insight for how it may affect spam/abuse

We could also do the invites one-by-one like we have to for room upgrades, but this would make the operation much much slower

[novocaine]

My view would be that if its a one time operation, it can be slow as long as we signal progress to the user. And doing it that way would be more robust on homeservers we can't re-config.

[t3chguy]

Need design on how to signal progress to the user as part of this interaction then

[markvoortman]

Thanks for all the prompt responses!

Can we increase it for matrix.org, which is where I think this bug is filed for?

That is correct, and would solve my immediate problem.

We could also do the invites one-by-one like we have to for room upgrades, but this would make the operation much much slower

I would be perfectly fine with waiting, as it's only a one-time operation, but a heads up to the user would be nice indeed.
I'm not familiar with the relevant code, but would it be an option to divide the work into reasonably sized batches?

[t3chguy]

but would it be an option to divide the work into reasonably sized batches?

Nope you can only batch invite at room creation time, any invites thereafter have to be singular. We also have no way of querying the server for its limit so can't even make use of that first larger batch.

[niquewoodhouse]

Need design on how to signal progress to the user as part of this interaction then

We have this as part of the add existing rooms dialog.

Can the same progress/error states be used?

[JoshStrobl]

Running into this as well except I don't even have 20 people in my Matrix (via matrix.org) community. Why is the rate limit so low?

[t3chguy]

Why is the rate limit so low?

That's a question for the matrix.org Ops team rather than an Element Web issue tracker but my best guess is to prevent someone mass spam inviting people to rooms.

[othot-mvoortman]

Thanks for the quick turnaround on this, much appreciated!