Ktistec v2.4.8 has many small fixes and improvements, but includes one significant fix to ActivityPub garbage collection, which was the major feature introduced in the last release.

⚠️ Important Note: Building with Crystal Language version 1.17.x is not supported due to two breaking changes. See:

• LibXML_Ext Issues #1
• Crystal Language PR #16055

(Maybe it's three changes—compile times are also far slower and executable sizes are much larger.)

Added

• Send "User-Agent" header identifying Ktistec on outbound HTTP requests.
• Add accept/reject action buttons to top panel on actor pages.

Fixed

• Add index on "username" on "actors" table. (Fixes a regression introduced in e659e84a.)
• Rejection now correctly sets follow relationships as confirmed (previously they remained pending).
• Fix garbage collection issues with threads created in earlier versions.

Changed

• Prioritize the author's self-replies in thread view.

Enjoy!

#ktistec #fediverse #activitypub #crystallang

After a mental health break, release v2.4.7 of Ktistec is out. The biggest improvement is the addition of a command line switch/option to run garbage collection on startup. Garbage collection, in this context, trims down your database by deleting old ActivityPub objects that are not connected to your user through:

• Attribution: Objects attributed to you or actors you follow
• Activities: Objects referenced by your activities or activities of actors you follow
• Collections: Objects in your timeline, notifications, or outbox
• Content: Objects with hashtags, mentions, or in threads you follow

It reduced the size of my database ~24%. Details on usage, warnings, etc. are in the README.

Other changes:

Fixed

• Use single quotes for string literals in SQLite queries.
• Fix WITH RECURSIVE queries.
• Fix broken CI workflow.

Changed

• Present local internal URLs as external URLs in posts.
• Limit pagination size for unauthenticated users.
• Better convey actor/object deleted/blocked status on index pages.
• Improve presentation of inline code and code blocks.
• Clip alt text on thumbnail images.

Other

• Update cached copy of Lemmy's JSON-LD context.

#ktistec #fediverse #activitypub #crystallang

Release v2.4.6 of Ktistec is out. As mentioned in an earlier post, this release focuses on database performance improvements. This means caching the results of expensive queries (like counting all posts with a particular hashtag or mention). On my instance at least, pages like the notifications page are now snappier.

There are still slow queries (queries that take more than 50msec). Most of those are requests for pages of old posts where none of the necessary database pages are in the page cache. I have increased the page cache size, and that reduces the frequency, but I don't see an immediate fix.

Fixed

• Add missing database query logging.

Changed

• Improve query performance for hashtags and mentions.
• Make less costly updates to tag statistics.
• Improve anonymous session management.
• Cache the Nodeinfo count of local posts.

Removed

• Remove support for X-Auth-Token.

Other

• Add timeout values for POST socket operations.

I don't have an immediate plan for the next release. There have been a bunch of feature requests that I think have merit. I'll probably get started on some of those.

#ktistec #fediverse #activitypub #crystallang

You can specify the SQLite database and pass options (pragmas like cache_size, journal_mode, ...) on the command line when you start the Ktistec server. The following example sets the cache size to 20,000 pages (up from the default of 2,000 pages) which improves performance on larger instances.

KTISTEC_DB=~/ktistec.db\?cache_size=-20000 ./server

You can also enable the write-ahead log (but make sure you know what that means).

KTISTEC_DB=~/ktistec.db\?journal_mode=wal\&synchronous=normal ./server

Pragmas supported are limited to those listed here.

#ktistec #fediverse #activitypub #crystallang

A new release of ktistec that improves database performance is imminent. In the past, database optimization usually meant "fixing a bunch of poorly constructed queries", and I'm sure there's more of that to do—I'm not an expert. But this time, I found most of the queries were as good as they were going to get on my watch (I'm not an expert). If you have a million records and you need to filter and count them, that's just going to take some time...

So this time, I focused on caching the results of queries like that (which really means I focused on cache invalidation, right). A case in point is commit d544b1af. Previously, the nodeinfo endpoint filtered and counted posts on every request, and it took +80msec to do that. Worse, the filtering pushed everything else out of the sqlite page cache, which made the next, unrelated database query slow!

Caching this value, and only recounting when I post something, not only dropped the service time for the request to ~1msec but actually improved database performance, generally!

More to come...

#ktistec #fediverse #activitypub #crystallang

If you're running an instance of Ktistec and want to see what other ActivityPub instances are sending you, turn on JSON-LD processing debug logging.

1. Go the the /system URL.
2. Find the ktistec.json_ld setting.
3. Select "Debug" and save.

Ktistec will dump received activities to the log, after the activity has been parsed into JSON but before JSON-LD expansion.

2025-01-22 14:53:17 UTC 409 POST /actors/toddsundsted/inbox 4.29ms
2025-01-22T14:53:17.597172Z  DEBUG - ktistec.json_ld: {"@context" => ["https://www.w3.org/ns/activitystreams", "https://w3id.org/security/v1"],
"id" => "https://random.site/users/FooBar#delete", "type" => "Delete", "actor" => "https://random.site/users/FooBar", "object" => "https://random.site/users/FooBar", "to" => ["https://www.w3.org/ns/activitystreams#Public"], 
"signature" => {"type" => "RsaSignature2017", "creator" => "https://random.site/users/FooBar#main-key", "created" => "2025-01-22T14:52:40Z", "signatureValue" => "01234567890abcdefghijklmnopqrstuvwxyz=="}}

Answer to a FAQ:
The server returns HTTP status code 409 ("Conflict") if it has already received an activity.

#ktistec #fediverse #activitypub

Ktistec release v2.4.5 rolls out the build time and executable size optimizations I've been blogging about here. It also fixes a few small bugs.

Fixed

• Handle @-mentions with hosts in new posts.
• Handle HEAD requests for pages with pretty URLs.
• Destroy session after running scripts.

Changed

• Delete old authenticated sessions.

I've started a branch full of query optimizations. My general rule—as highlighted in the server logs—is if a query takes longer than 50msec, it takes too long. It's time to address some problems...

#ktistec #fediverse #activitypub #crystallang

Ktistec release v2.4.4 fixes a few things in the prior release and introduces at least one killer feature!

Fixed

• Always get the attachments. (fixes #119)
• Don't run scripts until the server has been configured.

Changed

• ⭐️ Make the editor toolbar sticky.
• Clear the cached translator when the settings change.

I'm spending some cycles looking at the size of the server executable. You can read about my approach to reducing Crystal Language executable size and build time here.

#ktistec #fediverse #activitypub #crystallang

Ktistec release v2.4.3 supports language translation.

Inspiration for this feature comes from Mastodon.

In order to enable translation, you need an API key for either DeepL or LibreTranslate. These are the only services Ktistec supports at this time.

Posts from properly configured accounts on supported servers, like Mastodon, include the content language. On posts like these, Ktistec will display a button to translate the content if the language differs from your language.

Unfortunately, not all Fediverse/ActivityPub servers explicitly support language (I mean, Ktistec didn't until just now). And not all users correctly set their posts' language, so ymmv... but it has been hugely useful for me.

I'm going to focus on site customization next (colors, etc.).

#ktistec #fediverse #activitypub #crystallang

Release v2.4.2 fixes a few more bugs. Only one is a regression—I found the others while testing. In this release:

Fixed

• Fix metrics chart line labels.
• Permit del, ins, and s elements in sanitized HTML.
• Only store the redirect_after_auth_path on browser navigation.
• Add "content" property to editor JSON error response.
• Use FileUtils.mv to move uploaded files. (fixes #117)

Thanks to @jayvii for help with troubleshooting the last one!

#ktistec #fediverse #activitypub #crystallang