Merge pull request #2284 from beyonnex-io/ditto-387

Provide Ditto 3.8.7 release notes

Author: thjaeckle

documentation/src/main/resources/_data/sidebars/ditto_sidebar.yml

@@ -23,6 +23,9 @@ entries:
       - title: Release Notes
         output: web
         folderitems:
+          - title: 3.8.7
+            url: /release_notes_387.html
+            output: web
           - title: 3.8.6
             url: /release_notes_386.html
             output: web

documentation/src/main/resources/pages/ditto/release_notes_387.md

@@ -0,0 +1,83 @@
+---
+title: Release notes 3.8.7
+tags: [release_notes]
+published: true
+keywords: release notes, announcements, changelog
+summary: "Version 3.8.7 of Eclipse Ditto, released on 03.12.2025"
+permalink: release_notes_387.html
+---
+
+This is a bugfix release, no new features since [3.8.6](release_notes_386.html) were added.
+
+## Changelog
+
+Compared to the latest release [3.8.6](release_notes_386.html), the following changes and bugfixes were added.
+
+### Bugfixes
+
+This is a complete list of the
+[merged pull requests](https://github.com/eclipse-ditto/ditto/pulls?q=is%3Apr+milestone%3A3.8.7).
+
+#### Improve stability of ThingsAggregatorProxy in "things" service during restart
+
+PR [#2265](https://github.com/eclipse-ditto/ditto/pull/2265) introduces the "ask-with-retry" pattern when things
+are aggregated as result of a search request. This improves the stability by reducing errors during restarts of Ditto.
+
+#### Fix search timeout error handling
+
+In PR [#2268](https://github.com/eclipse-ditto/ditto/pull/2268) the error handling for search timeouts was fixed. Now,
+when a search request times out, a proper timeout error is returned instead of a generic internal server error.  
+And the `ERROR` log was replaced - as it is not a server issue in general if a user made an overly complex search request
+which lead to a timeout.
+
+#### Fix ordering problems on twin commands not requiring a response
+
+When a lot of twin (modifying) commands were sent to the same thing in a short time, the order of processing was not
+guaranteed in case the commands did not require a response (e.g. by unsing header `response-required: false` or `timeout: 0`).  
+PR [#2269](https://github.com/eclipse-ditto/ditto/pull/2269) fixes this issue.
+
+#### Fix wrong exceptions being thrown when duplicates occur in WoT parsing
+
+PR [#2276](https://github.com/eclipse-ditto/ditto/pull/2276) fixes that an internal server error (500) was returned on
+several WoT TD parsing errors, where a bad request error (400) would have been more appropriate.
+
+#### Add missing "authorization" header to make sure it is not written to external headers
+
+Up to now, if the `authorization` header was present in an incoming request, it was not explicitly removed from
+external headers sent to external systems (e.g. via a Ditto connection, HTTP or Kafka for example).  
+This was fixed via PR [#2278](https://github.com/eclipse-ditto/ditto/pull/2278) to make sure that e.g. no authentication
+information is leaked unintentionally.
+
+#### Fix retrieving thing for a message with a condition
+
+PR [#2279](https://github.com/eclipse-ditto/ditto/pull/2279) fixes an issue when a message was sent via Ditto containing
+a condition.  
+In such cases, the thing was not retrieved properly (e.g. authorization was bypassed and the original headers of the
+message sending were copied, e.g. copying also headers like `response-required` or `timeout`).
+
+#### Updating dependencies to fix issues
+
+* PR [#2273](https://github.com/eclipse-ditto/ditto/pull/2273) updates the used Kamon version to `2.8.0`
+* PR [#2282](https://github.com/eclipse-ditto/ditto/pull/2282) updates the used Rhino version (used for javascript payload mapping) to `1.8.1`
+
+
+### Helm chart
+
+#### Add possibility to configure tick-interval and queue-size for tracing exporter
+
+PR [#2270](https://github.com/eclipse-ditto/ditto/pull/2270) adds the possibility to configure `tick-interval` and `queue-size` 
+for the metrics/tracing library Ditto uses, Kamon.  
+Those values must e.g. be adjusted if spans are dropped due to high load (e.g. if the queue is full) or if the payload
+of sent spans to the OTEL backend must be reduced.
+
+#### Add feature toggle for configuring trace span metric reporting
+
+PR [#2275](https://github.com/eclipse-ditto/ditto/pull/2275) adds a configuration option for disabling the reporting of
+metrics for spans captured as part of tracing.  
+Those metrics can be quite many, as they are also reported as histograms.  
+When they are not needed, they can now be disabled to reduce the amount of metrics being sent to the metrics backend.
+
+#### Provide additional GC tuning config via Helm values
+
+PR [#2283](https://github.com/eclipse-ditto/ditto/pull/2283) contains additional Garbage collector configuration options
+which can be used to better fine-tune Ditto for specific memory needs.