[AIRFLOW-6095] Filter dags returned by task_stats

[robinedwards]

Jira

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Description

• Here are some details about my PR, including screenshots of any UI changes:

Add dag_ids parameter to task_stats end point so can filter by a set of dag_ids
present on the page. This is intended to speed up the response time
and reduce the size of the payload when running a large number of dags. I've experienced this endpoint taking up to 10 seconds and returning a 8mb (uncompressed) payload for around 1500 dags.

Note I have another branch against 1-10-test should this be approved.

Tests

• My PR adds the following unit tests:

See test_views.py

Commits

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  1. Subject is separated from body by a blank line
  2. Subject is limited to 50 characters (not including Jira issue reference)
  3. Subject does not end with a period
  4. Subject uses the imperative mood ("add", not "adding")
  5. Body wraps at 72 characters
  6. Body explains "what" and "why", not "how"

Documentation

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  • All the public functions and the classes in the PR contain docstrings that explain what it does
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• No documentation needed

[codecov-io]

Codecov Report

Merging #6684 into master will decrease coverage by <.01%.
The diff coverage is 95%.

@@            Coverage Diff             @@
##           master    #6684      +/-   ##
==========================================
- Coverage   83.88%   83.88%   -0.01%     
==========================================
  Files         668      668              
  Lines       37684    37694      +10     
==========================================
+ Hits        31612    31620       +8     
- Misses       6072     6074       +2

Impacted Files	Coverage Δ
airflow/www/views.py	76.77% <95%> (+0.16%)	⬆️
airflow/utils/dag_processing.py	52.13% <0%> (-0.39%)	⬇️

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[ashb]

is , allowed in DAGids? 😁

Also this parameter needs to be URI escaped, or bettwer yet if d3.json supports it d3.json("{{ url_for('Airflow.task_stats') }}", {"dag_ids": all_dags_ids.join(',') }, function(error, json) {

[robinedwards]

Passing get parameters like you suggested above wasn't supported by d3.json so instead I've encoded each dag_id. I thought about passing thedag_id= multiple times but it does result in a rather long GET header (which I believe is often capped at 8kb?). This could potentially overflow for users with 100 dags per page.

[mik-laj]

I think, we can use request.getlist("dag_ids") and send all request in seperate parameter e.g. url-view?dag_ids=AAA&dag_ids=AAA. Parameters should be encoded and so independent.

[robinedwards]

Hey sorry this got lost in my inbox. I still have to provide a PR for the /blocked endpoint. Happy to provide an additional PR switching the rest of the end points to use getlist() if you guys prefer it?

[ashb]

See comments

[ashb]

/cc @KevinYang21 You might find this useful.