4 ms·

> This is nothing to do with state resolution; it's due to Synapse's implementation deliberately cutting corners on storage efficiency while trading off for spe

> This is nothing to do with state resolution; it's due to Synapse's implementation deliberately cutting corners on storage efficiency while trading off for speed. It's specifically to increase the speed if *state resolution*. If it weren't for the convoluted state resolution system, there wouldn't be a need to store gigabytes worth of state groups in the database. * https://element-hq.github.io/synapse/latest/usage/administration/state_groups.html https://element-hq.github.io/synapse/latest/usage/administra... * https://github.com/matrix-org/rust-synapse-compress-state https://github.com/matrix-org/rust-synapse-compress-state Maybe there's a way to calculate state without state groups, but I sure don't see one that I can use if I were to run a matrix server. > Not since https://matrix.org/blog/2025/08/project-hydra-improving-stat https://matrix.org/blog/2025/08/project-hydra-improving-stat... Simply fixes some of the many ways that rooms can explode or be bricked. Zero confidence that room brickings are totally fixed once and for all. > There are MSCs for all of these now, and implementations are starting to filter through. The reality is that the project has been in a funding crunch since 2023 and we've had to focus on survival by prioritising stuff people pay for (i.e. big servers for govtech deployments) rather than custom emoji. A funding crunch since 2023 yet those features have been necessary for many years before 2023.

tcfhgj 10mo ago
The room state is cached to not need to recompute the current room state from the beginning of time. You probably would do that even if there was no state resolution at all > Simply fixes some of the many ways that rooms can explode or be bricked. How many other ways are there? Afaik none is known
- dfajgljsldkjag 10mo ago
  > Afaik none is known Before project hydra people didn't know about the room exploit either. They just knew that rooms exploded somehow every once in a while.
  - Arathorn 10mo ago
    Most people actually working on Matrix have been aware of state resets for quite a while. Hydra is just the name of the project which addresses them. There are 3 phases, of which the 1st covers the most serious ones; the 2nd and 3rd phases should drop next year. As an analogy, it's not dissimilar to how Git has added various different merge resolution approaches over the years in order to come up with more predictable and more "do what i mean" algorithms (resolve, recursive, ORT, octopus, etc). It's slightly different in that a bad merge in Matrix feels very unexpected and problematic, whereas manually unpicking collisions in a VCS is just part of the territory.
Arathorn 10mo ago
> It's specifically to increase the speed if state resolution. If it weren't for the convoluted state resolution system, there wouldn't be a need to store gigabytes worth of state groups in the database. No, it's specifically to increase the speed of state retrieval. One of the uses for that is state resolution, but it could equally well just be calling the /messages API or any other point you need to know historical state. But what do I know :)
- dfajgljsldkjag 10mo ago
  > it could equally well just be calling the /messages API or any other point you need to know historical state. State groups aren't really a thing for messages in a timeline, there are many easier ways of doing it, for example, simply storing the message sequentially (impossible in matrix though, due to the convoluted tree structure it uses) But when it comes to state (where state groups are actually needed) who actually needs a snapshot of the state at literally every point in history? Any other messaging app just needs to know the current state and maybe also an audit log of the change history for audit log purposes. In any sane messaging app (e.g. discord, slack, telegram etc.) there is exactly zero relevance in knowing the member list, room configuration, permissions and room title at exactly 2024-06-19T15:23:45Z. Who the heck cares??? Yet the design of matrix somehow makes this an integral part of every single operation.
  - Arathorn 10mo ago
    Perhaps just watch the video and see that the proposed solution is just doing a temporal state table - just as Slack and Discord etc must have in order to know what the state of a room was at some point in time.
    - dfajgljsldkjag 10mo ago
      Slack and discord don't know the state of the room at any given time in the past. Show me anywhere in slack or discord where you can see the membership of a room at 2024-06-19T15:23:45Z. Or anywhere where you can see the historical profile picture and nickname of everyone in the room at 2024-06-19T15:23:45Z. You can't, because they don't know.
rglullis 10mo ago
> A funding crunch since 2023 yet those features have been necessary for many years before 2023. But before 2023, the funding was going to things like solving state resolution, a VoIP system that was not dependent on Jitsi, getting rid of "could not decrypt message" errors, and so on.

tcfhgj 10mo ago

The room state is cached to not need to recompute the current room state from the beginning of time. You probably would do that even if there was no state resolution at all > Simply fixes some of the many ways that rooms can explode or be bricked. How many other ways are there? Afaik none is known

dfajgljsldkjag 10mo ago
> Afaik none is known Before project hydra people didn't know about the room exploit either. They just knew that rooms exploded somehow every once in a while.
- Arathorn 10mo ago
  Most people actually working on Matrix have been aware of state resets for quite a while. Hydra is just the name of the project which addresses them. There are 3 phases, of which the 1st covers the most serious ones; the 2nd and 3rd phases should drop next year. As an analogy, it's not dissimilar to how Git has added various different merge resolution approaches over the years in order to come up with more predictable and more "do what i mean" algorithms (resolve, recursive, ORT, octopus, etc). It's slightly different in that a bad merge in Matrix feels very unexpected and problematic, whereas manually unpicking collisions in a VCS is just part of the territory.

Arathorn 10mo ago

> It's specifically to increase the speed if state resolution. If it weren't for the convoluted state resolution system, there wouldn't be a need to store gigabytes worth of state groups in the database. No, it's specifically to increase the speed of state retrieval. One of the uses for that is state resolution, but it could equally well just be calling the /messages API or any other point you need to know historical state. But what do I know :)

dfajgljsldkjag 10mo ago
> it could equally well just be calling the /messages API or any other point you need to know historical state. State groups aren't really a thing for messages in a timeline, there are many easier ways of doing it, for example, simply storing the message sequentially (impossible in matrix though, due to the convoluted tree structure it uses) But when it comes to state (where state groups are actually needed) who actually needs a snapshot of the state at literally every point in history? Any other messaging app just needs to know the current state and maybe also an audit log of the change history for audit log purposes. In any sane messaging app (e.g. discord, slack, telegram etc.) there is exactly zero relevance in knowing the member list, room configuration, permissions and room title at exactly 2024-06-19T15:23:45Z. Who the heck cares??? Yet the design of matrix somehow makes this an integral part of every single operation.
- Arathorn 10mo ago
  Perhaps just watch the video and see that the proposed solution is just doing a temporal state table - just as Slack and Discord etc must have in order to know what the state of a room was at some point in time.
  - dfajgljsldkjag 10mo ago
    Slack and discord don't know the state of the room at any given time in the past. Show me anywhere in slack or discord where you can see the membership of a room at 2024-06-19T15:23:45Z. Or anywhere where you can see the historical profile picture and nickname of everyone in the room at 2024-06-19T15:23:45Z. You can't, because they don't know.

rglullis 10mo ago

> A funding crunch since 2023 yet those features have been necessary for many years before 2023. But before 2023, the funding was going to things like solving state resolution, a VoIP system that was not dependent on Jitsi, getting rid of "could not decrypt message" errors, and so on.