DynamoDB Leader Monitor: On Next Should Always Provide MasterDescription

[crioux-stripe]

This is an extension of @kmg-stripe 's fix in #691 that is ready to merge.

Context

The DynamoDBMasterMonitor had cases where it may propagate a null value when getLatestMaster() is called, despite having some protections against it. I've removed the AtomicReference to the latest and just rely on the BehaviorSubject to return the latest value.

Checklist

• ./gradlew build compiles code correctly
• Added new tests where applicable
• ./gradlew test passes all tests
• Extended README or added javadocs where applicable

[github-actions]

Test Results

535 tests  +1   529 ✅ +1   7m 52s ⏱️ -5s
139 suites ±0     6 💤 ±0 
139 files   ±0     0 ❌ ±0 

Results for commit 49c8edd. ± Comparison against base commit 10c1dd8.

♻️ This comment has been updated with latest results.

[crioux-stripe]

I don't have tag pushing rights, but if someone could tag this v3.1.1-rc.1 that would be awesome!

[Andyz26]

I don't have tag pushing rights, but if someone could tag this v3.1.1-rc.1 that would be awesome!

@crioux-stripe I think @kmg-stripe was able to push the RC tag, and you have the same role in settings. Can you try pushing the tag and let me know if you get any errors?

[crioux-stripe]

@Andyz26 I did think it was kind of odd but I'm getting:

crioux@st-crioux1 mantis % git push origin tag v3.1.1-rc.1
ERROR: Permission to netflix/mantis.git denied to crioux-stripe.
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
crioux@st-crioux1 mantis % cat .git/config
[core]
	repositoryformatversion = 0
	filemode = true
	bare = false
	logallrefupdates = true
	ignorecase = true
	precomposeunicode = true
[remote "origin"]
	url = [email protected]:netflix/mantis.git
	fetch = +refs/heads/*:refs/remotes/origin/*
[branch "master"]
	remote = origin
	merge = refs/heads/master

[Andyz26]

@crioux-stripe, hmm, this is weird: "fatal: Could not read from remote repository." Maybe try reattaching the public SSH keys?
I just checked again, and there is no difference between your account setting and Kevin's. @sarahwada-stripe also got the same permission role. Does it work for you?

[crioux-stripe]

@Andyz26

That did the trick. The default Stripe one appeared to be an older RSA key. I added a new ed25519 key and everything appears to work:

crioux@st-crioux1 mantis % git push
Everything up-to-date

(This used to produce an error.)