Compress telemetry metadata to reduce serialized DAG size #2252
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Pull request overview
This PR implements gzip compression with base64 encoding for telemetry metadata to reduce the size of serialized DAGs in Airflow's database. The compression is applied when storing metadata in dag.params and decompressed when reading it back.
Key changes:
- Added compression/decompression utility functions using gzip (level 9) and base64 encoding
- Updated the converter to compress metadata before storage with size comparison logging
- Modified the dag_run_listener to safely decompress metadata with proper exception handling
Reviewed changes
Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.
Show a summary per file
| File | Description |
|---|---|
| cosmos/telemetry.py | Adds _compress_telemetry_metadata() and _decompress_telemetry_metadata() helper functions |
| cosmos/converter.py | Compresses metadata before storing in dag.params and logs size comparison |
| cosmos/listeners/dag_run_listener.py | Updates get_cosmos_telemetry_metadata() to decompress metadata with error handling |
| tests/test_converter.py | Verifies compression by checking metadata type and decompressing for content validation |
| tests/listeners/test_dag_run_listener.py | Adds tests for handling invalid compressed data and missing metadata cases |
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Screenshot showing compressed encoded data in the conf: |
tatiana
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Thanks for improving this so quickly, @pankajkoti ! I left a minor comment, and I'm happy with the implementation.
Implement gzip compression + base64 encoding for telemetry metadata stored in dag.params. This reduces the size of serialized DAGs in Airflow's database. Changes: - Add _compress_telemetry_metadata() and _decompress_telemetry_metadata() to cosmos/telemetry.py - Update converter to compress metadata before storing in dag.params - Update dag_run_listener to decompress metadata when reading - Catch specific exceptions during decompression (binascii.Error, gzip.BadGzipFile, json.JSONDecodeError, EOFError) - Add size comparison logging - Update tests to verify compression
Set mtime=0 in gzip.compress() to make compression deterministic. Without this, gzip includes a timestamp in the header, causing the compressed output to differ slightly each time even with identical input. This broke Airflow's Param const validation which requires the value to remain exactly the same.
Test that get_cosmos_telemetry_metadata gracefully handles invalid compressed data and missing metadata by returning empty dict instead of raising exceptions.
Add explanation in docstring that mtime=0 ensures deterministic compression output, preventing Airflow Param validation errors. Add tests to verify compression is deterministic and roundtrip works correctly.
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
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Features * Support cross-referencing models across dbt projects using dbt-loom by @pankajkoti in #2271 * Support use of YAML selectors when using ``LoadMode.DBT_MANIFEST`` by @YourRoyalLinus in #2261 * Introduce ``ExecutionMode.WATCHER_KUBERNETES`` to use the watcher with ``KubernetesPodOperator`` by @tatiana in #2207 * Add support for StarRocks profile mapping by @kurkim0661 in #2256 * Allow pushing URIs as XComs for Cosmos tasks by @corsettigyg in #2275 * Support defining custom callbacks alongside the ``WATCHER_KUBERNETES`` callback by @johnhoran in #2307 Enhancements * Refactor: remove duplicate ``_construct_dest_file_path`` by @jx2lee in #2077 * Leverage Airflow ``::group::`` to group logs associated with DAG parsing by @tatiana in #2235 * Refactor ``DbtConsumerWatcherSensor`` for reusability by @tatiana in #2245 * Restore plain text output when using ``ExecutionMode.WATCHER`` by @tiovader in #2241 Bug Fixes * Fix running empty models or ephemeral nodes in ``ExecutionMode.WATCHER`` by @tatiana in #2279 * Improve watcher producer task priority in scheduling and the UI by @tatiana in #2237 * Fix typos and formatting issues in documentation by @pankajkoti in #2259 * Allow watcher producer retries without erroring by @tatiana in #2283 * Fix ``TestBehavior.AFTER_ALL`` is missing project_name information when loading project using manifest file by @tuantran0910 in #2242 * Fix duplicate log lines in watcher subprocess execution and format timestamps by @pankajkoti in #2301 Docs * Add Watcher Kubernetes documentation by @tatiana in #2303 * Document newly added telemetry metrics in the privacy notice by @pankajkoti in #2249 * Add compatibility policy document by @pankajastro in #2251 * Improve watcher documentation related to dbt threads by @tatiana in #2273 * Fix link in watcher execution mode documentation by @jedcunningham in #2277 * Update Apache Airflow minimum compatibility policy by @tatiana in #2285 * Clarify Cosmos runtime support until "End of Basic Support" by @jedcunningham in #2286 * Update watcher docs by @tatiana in #2298 * Update watcher kubernetes documentation by @tatiana in #2306 Others * Add Airflow 3 DAG versioning tests for Cosmos by @michal-mrazek in #2177 * Add dbt Core 1.11 to the test matrix by @tatiana in #2230 * Add integration tests using InvocationMode.SUBPROCESS and validate output by @tatiana in #2287 * Fix main branch failing tests by @tatiana in #2296 * Update pre-commit hooks to the latest versions by @jedcunningham in #2289 * Pre-commit autoupdates by @pre-commit in #2222, #2264, #2274 and #2290 * Dependabot updates by @dependabot in #2218, #2219, #2220, #2280 and #2284 * Add Scarf metrics to understand Cosmos feature usage patterns - Add telemetry tracking for dbt docs plugin usage by @pankajkoti in #2240 - Add DAG run telemetry metrics for load mode, invocation, and render_config parameters by @pankajkoti in #2223 - Collect profile metrics for DAG runs by @pankajastro in #2228 - Compress telemetry metadata to reduce serialized DAG size by @pankajkoti in #2252 - Skip storing telemetry metadata when emission is disabled by @pankajkoti in #2278 - Hide telemetry metadata parameters from the Airflow trigger UI by @pankajkoti in #2247 closes: astronomer/oss-integrations-private#317 --------- Co-authored-by: Tatiana Al-Chueyr <tatiana.alchueyr@gmail.com>
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Implement gzip compression + base64 encoding for telemetry metadata stored in dag.params. This reduces the size of serialized DAGs in Airflow's database.
Changes:
related: #2223
closes: https://github.com/astronomer/oss-integrations-private/issues/300