Moving from Synapse

[TheSunCat]

Hi,
I was patiently waiting on potential Synapse migration support as part of #2 but unfortunately yesterday partially deleted its database, alongside finding out my backups... weren't backups. In case what I have isn't recoverable, that means it's a good time as any to make the switch to Tuwunel.

Before attempting it, I want to ask here whether any issues are expected given I was previously hosting a federated Synapse homeserver at the same URL, with users that had the same handles. Is there some cleanup I need to do to inform the federation of this switch? Do I need to do any other special steps to make it "work" (besides of course re-creating all my users and having them rejoin the rooms they were in)?

[jevolk]

There is nothing explicit you need to do. Federation will start to just work again. I'm not certain if our server is capable of downloading its own public keys (the last server's public keys with the matching domain) from the notary but I think so and I haven't heard of any issues from many others who have done this same migration. In summary you should be able to rejoin your old rooms and maintain any admin status you previously had. And yes to be clear you will have to manually recreate these accounts the same as before and rejoin rooms as if it was the first time.

Clients will have to nudge their new encryption identity with remote users; again nothing explicit you have to do, but it just may be a little annoying with a few UTD 's that will have to resolve themselves with a little back and forth use.

Overall, Matrix is capable of this operation and there is nothing specific you have to do. It might be a little bumpy in the beginning but any issues will resolve themselves especially with more use.

[TheSunCat]

Thanks for confirming! I went ahead and tried it, indeed I can still join rooms... but I am having trouble with DMs. Trying to
DM a friend "invites" them to a new room, and then they see two rooms with my account (the old one and the new one). Is there any way I can regain access to the old DMs (and read the encrypted chats)?
I still have one offline FluffyChat session that has the old rooms cached, and I have the old account's secure backup key.

[jevolk]

You can definitely join the old DM; having them invite you might be easiest, but directly joining should work I think. Seeing old message history will likely not be possible. It depends on how robust the client is but chances are it will be confused by having lost the expected server state. All I can suggest is inputting your existing saved keys without performing any explicit identity resets and hoping it can recover.

[TheSunCat]

I guess this would be something on the client's end? I don't know how to get my old keys from that old/offline FluffyChat session, or how to input them back into my new one.

[jevolk]

In theory you should be able to do this but in practice I wouldn't have high hopes. It's definitely something that depends on the client and they would need to support you.

[TheSunCat]

Thanks so much for the info and help! I was able to rejoin my old DMs by using /join https://matrix.to/#/!roomid:myhomeserver.org?via=theirhomeserver.com
Unfortunately no message history, I have to get each friend to export their E2EE keys for the DM room and send me them.

I guess the last thing would be re-creating the non-federated rooms that were in my old homeserver; I have little hope of recovering those though.