Synapse 1.69 released

Hey everyone, it's time for a new Synapse release! Synapse 1.69 is out, fresh out of the oven. But before we take a look at it, here's a quick announcement:

We have recently disclosed a moderate severity security vulnerability, which was fixed in Synapse 1.62 (released on July 5th 2022). This issue affects all homeservers running a version of Synapse older than 1.62 with open federation. If this is the case for your deployment, please update to a more recent version of Synapse at your earliest convenience.

See advisory GHSA-jhjh-776m-4765 and CVE-2022-31152 for more information.

Now let's see what's new in Synapse 1.69!

🔗Caching in modules

Synapse modules allow third-party developers to extend Synapse's feature range to include very custom features.

Synapse 1.69 includes tools modules can use to interact with Synapse's caching system, which includes features such as synchronising caches across multiple Synapse workers.

Starting with this version, modules can import the @cache() decorator from synapse.module_api, to decorate functions which results must be cached. Cached functions need to be registered with ModuleApi.register_cached_function at the module's initialisation. Invalidating a cached function's result for a given set of arguments can be done using ModuleApi.invalidate_cache.

🔗Upcoming removal of deprecated Prometheus metric names

Back in Synapse 1.2, we deprecated a number of Prometheus metrics, to replace them with more aptly named equivalents that fit existing naming conventions better.

With Synapse 1.69, we're announcing the plan for the removal for these deprecated metrics. Synapse 1.71 (due to be released on November 8) will turn these metrics off by default (though it will still be possible to enable them back). Synapse 1.73 (due to be released on November 22) will remove them altogether.

Server administrators using metrics dashboards that rely on the deprecated metrics are encouraged to update their dashboards with the new metric names. See the upgrade notes for more information.

🔗Everything else

Synapse 1.69 also deprecates the generate_short_term_login_token module API method in favour of the asynchronous create_login_token one. The deprecated method will be removed in Synapse 1.71. See the upgrade notes for more information.

Additionally, Synapse 1.69 introduces a forwards- and backwards-incompatible change to the replication of read receipts. This means that read receipts replicated by workers running Synapse 1.68 will not be able to be processed by workers running Synapse 1.69 and vice-versa. Once all workers are made to run Synapse 1.69 (or 1.68), replication of read receipts will resume as normal. See the upgrade notes for more information.

See the full changelog for a complete list of changes in this release. Also please have a look at the upgrade notes for this version.

Synapse is a Free and Open Source Software project, and we'd like to extend our thanks to everyone who contributed to this release, including (in no particular order) lukasdenk, Dirk Klimpel, Ashish Kumar, Famedly and Beeper, as well as anyone helping us make Synapse better by sharing their feedback and reporting issues.