User:Samtar/Why isn't ExternalLinksChange working

ExternalLinksChange (an EventLogging schema) isn't working as expected

Bug

Expected behaviour

1. Add an external link to any page on test.wikipedia
2. Wait up to 1 hour
3. Run a query on stat1003 and the change is logged

Real behaviour

1. Add an external link to any page on test.wikipedia
2. Wait up to 1 hour
3. Run a query on stat1003 and the change is sometimes logged
4. Wait longer
5. Run a query on stat1003 and the change might be there
6. Wait even longer
7. Run a query on stat1003 and the change still isn't there
8. Give up and conclude it's been missed (probably?)

What have we tried?

• Making the change to articlespace on test.wikipedia - still randomly misses log entries
• Adding a link which gets logged in the spam blacklist on test.wikipedia - blacklist logs, still randomly misses

Where should we debug?

• Beta cluster would be good as we can tail the log and see what's going on - we should enable the schema there and get sudo (relevant) - Not to be used as a development playground, but will be useful in later debugging
• Labs project instance - asking -labs if this is a suitable use of an instance - Currently setting up
• Local MW install via vagrant - Should probably do this anyway..

Useful links

• Extension
• Personal debugging task
• Labs project for debugging
• Grafana of schema hits