Thousands of REST requests on reload

[richvdh]

Steps to reproduce

1. Be logged into my account
2. Ctrl-R

Outcome

What did you expect?

Normality

What happened instead?

Operating system

Ubuntu 22.04

Application version

Element version: 7164aeb-react-90b572f07413-js-3a694f499841 Olm version: 3.2.14

How did you install the app?

develop.element.io

Homeserver

synapse 1.83.0

Will you send logs?

No

[richvdh]

Looking at the HAR, some particularly egregious examples:

    297 GET https://matrix.sw1v.org/_matrix/client/r0/rooms/!ZKwMrTfYLckrZBadAb%3Amatrix.org/event/%24SPP6iXpWK7ak_Crg4JYqlFwfM4Taj9a-97-alR50wT0
    149 GET https://matrix.sw1v.org/_matrix/client/v1/rooms/!ZKwMrTfYLckrZBadAb%3Amatrix.org/relations/%24UCZ8ueiXAV08RV3xi5cR-k14Xzb_gt7AFfgkbHlC5AY/m.replace/m.room.encrypted?limit=1
    149 GET https://matrix.sw1v.org/_matrix/client/r0/rooms/!ZKwMrTfYLckrZBadAb%3Amatrix.org/event/%24UCZ8ueiXAV08RV3xi5cR-k14Xzb_gt7AFfgkbHlC5AY
    148 GET https://matrix.sw1v.org/_matrix/client/v1/rooms/!ZKwMrTfYLckrZBadAb%3Amatrix.org/relations/%24SPP6iXpWK7ak_Crg4JYqlFwfM4Taj9a-97-alR50wT0/m.replace/m.room.encrypted?limit=1

(The first column is number of requests. In practice, the number of requests is doubled because each gets a CORS preflight.)

• !ZKwMrTfYLckrZBadAb:matrix.org/ $SPP6iXpWK7ak_Crg4JYqlFwfM4Taj9a-97-alR50wT0 is the start of a fairly long thread, but I don't think that's any reason we need to ask for the the event itself 297 times and its relations 148 times.
• !ZKwMrTfYLckrZBadAb:matrix.org/ $UCZ8ueiXAV08RV3xi5cR-k14Xzb_gt7AFfgkbHlC5AY is the other end of the same thread.

In total, there are 1068 GET /_matrix/client/r0/rooms/[^/]*/event/ requests, and 738 /_matrix/client/v1/rooms/[^/]*/relations/ requests.

[kerryarchibald]

Duplicate of #25395?

[richvdh]

yes indeed, thanks!