Deflakes Primary COB growth with inactive replica

[sarthakaggarwal97]

Resolves #2696

The test is passing for past 7 consecutive iterations for test-sanitizer-address in my daily runs. I amended log to show the current backlog if it doesn't reach 2x.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.62%. Comparing base (155b0bb) to head (db6e772).
⚠️ Report is 1 commits behind head on unstable.

Additional details and impacted files

@@             Coverage Diff              @@
##           unstable    #2715      +/-   ##
============================================
+ Coverage     72.40%   72.62%   +0.21%     
============================================
  Files           128      128              
  Lines         71273    71273              
============================================
+ Hits          51606    51759     +153     
+ Misses        19667    19514     -153     

see 19 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[zuiderkwast]

LGTM

[enjoy-binbin]

can you give some clues? is that how (or where) did you determine the timeout and why increasing rdb-key-save-delay helped? We can add more info in the top comment and then merge it into. The analysis info is also very useful in these timing issues