Before this PR:
TimestampPaxosResource, used for Paxos per client to acquire timestamp bounds, contains subresource locators and is mounted on Jersey.
After this PR:
TimestampPaxosResource is flattened into two resources with those registered as both Jersey and Undertow resources.
==COMMIT_MSG==
==COMMIT_MSG==
Priority:
P2
Concerns / possible downsides (what feedback would you like?):
Similar concerns from the other PRs:
Client.java validation is weird and may be wrong
I posted some thoughts internally on that and why it's probably okay; subject to testing later of course (I will prepare a list of RPCs and run them both on develop and on the tip of the migration PRs)
I also posted a list of all APIs I'd expect timelock wrapper to expose and reduced that to a tree to check for possible ambiguity or unexpected swaps
I self-reviewed multiple times, but eyes get fatigued and used to these annotations. Please ping me right before the review and I can look at it again
Also available to pair on this
This PR does two things wherein things can go wrong: flatten the existing Jersey resource and then converting to Undertow. To ease the review, refer to the RPC client version of this (allows looking at this on the same Intellij, given I removed the original file), those would be TimelockPaxos(Acceptor|Learner)RpcClient
Is documentation needed?:
No
Compatibility
Does this PR create any API breaks (e.g. at the Java or HTTP layers) - if so, do we have compatibility?:
Should not impact what requests succeed or fail, or what success returns. May change things in terms of how RPCs fail (though not meaningfully, as the undertow ones are wrapped in some exception handling thingy somewhere)
Does this PR change the persisted format of any data - if so, do we have forward and backward compatibility?:
No
The code in this PR may be part of a blue-green deploy. Can upgrades from previous versions safely coexist? (Consider restarts of blue or green nodes.):
Yes
Does this PR rely on statements being true about other products at a deployment - if so, do we have correct product dependencies on these products (or other ways of verifying that these statements are true)?:
No
Does this PR need a schema migration?
No
Testing and Correctness
What, if any, assumptions are made about the current state of the world? If they change over time, how will we find out?:
N/A
What was existing testing like? What have you done to improve it?:
Pending
If this PR contains complex concurrent or asynchronous code, is it correct? The onus is on the PR writer to demonstrate this.:
N/A
If this PR involves acquiring locks or other shared resources, how do we ensure that these are always released?:
N/A
Execution
How would I tell this PR works in production? (Metrics, logs, etc.):
Similar to previous PRs: no 500s, TimeLock can B/G into this version and can downgrade from it without 500s, performance is not impacted negatively and leader elections go as usual.
Has the safety of all log arguments been decided correctly?:
Yes
Will this change significantly affect our spending on metrics or logs?:
No
How would I tell that this PR does not work in production? (monitors, etc.):
Any of the bits that tell it works fail, in addition to failures to startup because of obscure dependency/classpath conflicts or stuck upgrade excavator
If this PR does not work as expected, how do I fix that state? Would rollback be straightforward?:
Recall and rollback
If the above plan is more complex than “recall and rollback”, please tag the support PoC here (if it is the end of the week, tag both the current and next PoC):
Scale
Would this PR be expected to pose a risk at scale? Think of the shopping product at our largest stack.:
No
Would this PR be expected to perform a large number of database calls, and/or expensive database calls (e.g., row range scans, concurrent CAS)?:
No
Would this PR ever, with time and scale, become the wrong thing to do - and if so, how would we know that we need to do something differently?:
No
Development Process
Where should we start reviewing?:
If this PR is in excess of 500 lines excluding versions lock-files, why does it not make sense to split it?:
Please tag any other people who should be aware of this PR:
@jeremyk-91
@sverma30
@raiju
General
Before this PR: TimestampPaxosResource, used for Paxos per client to acquire timestamp bounds, contains subresource locators and is mounted on Jersey. After this PR: TimestampPaxosResource is flattened into two resources with those registered as both Jersey and Undertow resources. ==COMMIT_MSG== ==COMMIT_MSG==
Priority: P2 Concerns / possible downsides (what feedback would you like?): Similar concerns from the other PRs:
Compatibility
Does this PR create any API breaks (e.g. at the Java or HTTP layers) - if so, do we have compatibility?: Should not impact what requests succeed or fail, or what success returns. May change things in terms of how RPCs fail (though not meaningfully, as the undertow ones are wrapped in some exception handling thingy somewhere) Does this PR change the persisted format of any data - if so, do we have forward and backward compatibility?: No The code in this PR may be part of a blue-green deploy. Can upgrades from previous versions safely coexist? (Consider restarts of blue or green nodes.): Yes Does this PR rely on statements being true about other products at a deployment - if so, do we have correct product dependencies on these products (or other ways of verifying that these statements are true)?: No Does this PR need a schema migration? No
Testing and Correctness
What, if any, assumptions are made about the current state of the world? If they change over time, how will we find out?: N/A What was existing testing like? What have you done to improve it?: Pending If this PR contains complex concurrent or asynchronous code, is it correct? The onus is on the PR writer to demonstrate this.: N/A If this PR involves acquiring locks or other shared resources, how do we ensure that these are always released?: N/A
Execution
How would I tell this PR works in production? (Metrics, logs, etc.): Similar to previous PRs: no 500s, TimeLock can B/G into this version and can downgrade from it without 500s, performance is not impacted negatively and leader elections go as usual. Has the safety of all log arguments been decided correctly?: Yes Will this change significantly affect our spending on metrics or logs?: No How would I tell that this PR does not work in production? (monitors, etc.): Any of the bits that tell it works fail, in addition to failures to startup because of obscure dependency/classpath conflicts or stuck upgrade excavator If this PR does not work as expected, how do I fix that state? Would rollback be straightforward?: Recall and rollback If the above plan is more complex than “recall and rollback”, please tag the support PoC here (if it is the end of the week, tag both the current and next PoC):
Scale
Would this PR be expected to pose a risk at scale? Think of the shopping product at our largest stack.: No Would this PR be expected to perform a large number of database calls, and/or expensive database calls (e.g., row range scans, concurrent CAS)?: No Would this PR ever, with time and scale, become the wrong thing to do - and if so, how would we know that we need to do something differently?: No
Development Process
Where should we start reviewing?:
If this PR is in excess of 500 lines excluding versions lock-files, why does it not make sense to split it?:
Please tag any other people who should be aware of this PR: @jeremyk-91 @sverma30 @raiju