Default rate limit on joins breaks profile picture and display name updates to propagate to rooms

[csett86]

Description

Since #8008 joins are rate-limited. As profile picture updates are send out to all rooms as a burst of "join" events, these are effectively broken and only distributed to a very small number of rooms (~3).

Steps to reproduce

• Have Synapse 1.19.0
• Change profile picture or display name in user preferences
• Profile picture / display name update is not reflected in rooms, but logs are filled with:

2020-08-23 21:11:23,608 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,622 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,642 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,658 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,689 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,703 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,720 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,753 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.de - 429: Too Many Requests
2020-08-23 21:11:23,765 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,786 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,807 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,830 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,846 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,865 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,882 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,899 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,909 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.io - 429: Too Many Requests
2020-08-23 21:11:23,924 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.xyz - 429: Too Many Requests
2020-08-23 21:11:23,938 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:23,964 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.im - 429: Too Many Requests
2020-08-23 21:11:23,979 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests
2020-08-23 21:11:24,008 - synapse.handlers.profile - 297 - WARNING - PUT-149100 - Failed to update join event for room !REDACTED:example.org - 429: Too Many Requests

• Setting the join rate-limiting burst to something larger than the rooms you are in, the profile updates are again working.

Version information

• Homeserver: matrix.org
• Homeserver: settgast.org

If not matrix.org:

• Version: 1.19.0

• Install method: package manager

• Platform: Ubuntu 18.04

[ghost]

can confirm! was causing me a huge headache.

I feel that this should be tagged as a fire. The way to temporarily fix this is to set rc_joins to a higher burst, which may have to be a high number and can easily be abused.

[babolivier]

Thanks for your report! This is indeed a pretty serious regression caused by #8008, which will be fixed in #8153, and released in 1.19.1 later this week.

[babolivier]

#8153 has been merged into the release branch, so I'm closing this issue.

[babolivier]

FYI the fix to this issue has just been released in Synapse v1.19.1 🙂

[csett86]

Dear @babolivier, thank you for quickly fixing and releasing the patched version!

[ghost]

Excellent! Thanks for your work!