Highlights

• Added offline deduplication that helps saving even more space on the remote object storage & increases query performance
• The receive dual-mode has been implemented
• Receive now is able to ingest exemplars and it is possible to query them
• Receive now uses a few percent less of CPU time with the same load

This release contains improvements from 27 authors (git log --pretty="%ae" origin/release-0.21...origin/release-0.22 | sort | uniq | wc -l)! Thanks to all of them! Thanos wouldn't be what it is without all of their effort and time! ❤️

Added

• #4394 Add error logs to receiver when write request rejected with invalid replica
• #4403 UI: Add sorting and filtering to flags page
• #4299 Tracing: Add tracing to exemplar APIs.
• #4327 Add environment variable substitution to all YAML configuration flags.
• #4239 Add penalty based deduplication mode for compactor.
• #4292 Receive: Enable exemplars ingestion and querying.
• #4392 Tools: Added --delete-blocks to bucket rewrite tool to mark the original blocks for deletion after rewriting is done.
• #3970 Azure: Adds more configuration options for Azure blob storage. This allows for pipeline and reader specific configuration. Implements HTTP transport configuration options. These options allows for more fine-grained control on timeouts and retries. Implements MSI authentication as second method of authentication via a service principal token.
• #4406 Tools: Add retention command for applying retention policy on the bucket.
• #4430 Compact: Add flag downsample.concurrency to specify the concurrency of downsampling blocks.
• #4231 Receive: Implemented the receive dual-mode. This means that it is now you can run receive as ingester (TSDB only, no hashring awareness), as router (no TSDB, only forwarding mode) and old mode (router + ingester) in one service. Consider splitting functionality if you want to scale your hashring into multiple rings or you want horizontally autoscale your ingester more often.
• #3678 UI: add support for new duration format in graph range input. Now it is possible to use composite durations such as 5m30s.

Fixed

• #4384 Fix the experimental PromQL editor when used on multiple line.
• #4342 ThanosSidecarUnhealthy doesn't fire if the sidecar is never healthy
• #4388 Receive: fix bug in forwarding remote-write requests within the hashring via gRPC when TLS is enabled on the HTTP server but not on the gRPC server.
• #4340 UI: now displays the duration and all annotations of an alert in the alerts page.
• #4348 Fixed parsing of the port in the log middleware.
• #4417 UI: fixed the night mode in Bucket UI.

Changed

• #4354 Receive: use the S2 library for decoding Snappy data; saves about 5-7% of CPU time in the Receive component when handling incoming remote write requests
• #4369 Build: Pin upgrade Alpine's version.
• #4404 Receive: added extra validation for the tenant's label name. Some unsupported formats could have passed before.