A100: Client-side WRR slow start configuration #498

anuragagarwal561994 · 2025-05-31T04:49:04Z

No description provided.

ejona86 · 2025-06-02T14:20:30Z

anuragagarwal561994 · 2025-06-06T08:44:28Z

@dfawley did we get a chance to check this

atollena

This would be a nice addition (it's something we've had requests for internally at Datadog). Generally the approach sounds good to me. Ideally we would be able to support this mechanism for other load balancers supported by gRPC and Envoy (lr & rr). But given that lr & rr do not implement endpoint weights, it seems difficult to fit the feature in those balancers.

client-side-weighted-round-robin-slow-start.md

anuragagarwal561994 · 2025-06-06T18:55:08Z

@atollena I have addressed your comments regarding the proposal, let me know if I need to make any changes in it

anuragagarwal561994 · 2025-06-16T08:38:48Z

@ejona86 @atollena I have addressed the new comments, requesting review for any futher modifications needed

anuragagarwal561994 · 2025-06-19T15:02:46Z

@ejona86 can I start with the implementation of the feature?

anuragagarwal561994 · 2025-06-30T08:00:14Z

@ejona86 @atollena will it be possible to review the proposal this week so that I can begin with the implementation of the feature

atollena

It would be useful to see an implementation of this in one of the 3 languages. I wouldn't wait for the gRFC to be approved before starting, especially since the result can be used as a custom, private LB policy before it is merged to upstream-supported gRPC implementations.

client-side-weighted-round-robin-slow-start.md

atollena · 2025-07-01T11:24:13Z

client-side-weighted-round-robin-slow-start.md

+
+## Implementation
+
+This will be implemented in all languages C++, Java, and Go.


This is a good place to add the actual implementation of your choice when you have it ready (it can be a draft or closed PR that you can re-open once the gRFC has been approved).

I have added the implementation for Java, would love if you could review the changes :)

grpc/grpc-java#12200

client-side-weighted-round-robin-slow-start.md

anuragagarwal561994 · 2025-07-02T13:11:24Z

@atollena I have opened the respective MR at the envoy side as well, they will merge it once the proposal is approved at our end. For this proposal I just need to handle the case for the timing part and make the respective changes in the proposal once done I will assign for re-review.

anuragagarwal561994 · 2025-07-07T17:31:06Z

@atollena @ejona86 so I have created a rough implementation, not updated the test cases as of now.

I have also updated the proto on the envoy side, but to merge it we require to approve this proposal, then sync the proto may be in a separate MR.

How should we go about this?

atollena

👍

A100-client-side-weighted-round-robin-slow-start.md

dfawley

This mostly seems fine to me, I just have some nits. Also, since I don't see a slow start config in the envoy WRR policy proto, I'm curious if you've (or someone else has?) sent a proposal to add it there already.

A100-client-side-weighted-round-robin-slow-start.md

dfawley · 2025-07-17T21:28:27Z

A100-client-side-weighted-round-robin-slow-start.md

+
+## Metrics
+
+The following metric will be exposed to help monitor the slow start behavior:


How important is this metric to include? Should we consider not adding it until it's needed?

Ideally in most of the cases the slow_start_window will be applicable only for a short duration like 1-2 mins and if everything works well, it will not be called again.

I just thought that we can implement it in disabled mode, if someone wants to keeps a track of it.

We can decide this and I will make the respective changes in the proposal

anuragagarwal561994 · 2025-07-18T05:59:29Z

@dfawley envoyproxy/envoy#40090 this is the MR I have created at envoy's end to include the slow_start_config in proto.

However it requires this grpc proposal to be approved first before it is merged to the master.

Then we will need to sync across repo and then we are good to implement this feature. I have added sample MR with the java implementation as well, please do check it as well.

markdroth

Thanks for writing this up!

A100-client-side-weighted-round-robin-slow-start.md

anuragagarwal561994 · 2025-07-20T10:43:35Z

@markdroth I have made the respective changes and added a few comments for where I was confused, please help me resolve the same.

anuragagarwal561994 · 2025-08-07T07:29:39Z

@ejona86 @markdroth @atollena @dfawley can we re-check the latest changes and re-review the same.

markdroth

Sorry for the delay; I was on vacation for a few weeks, and I got Covid while I was out, and I'm still recovering...

This looks good overall, but the config content still needs work.

Please let me know if you have any questions.

A100-client-side-weighted-round-robin-slow-start.md

Signed-off-by: anurag.ag <[email protected]>

Co-authored-by: Antoine Tollenaere <[email protected]>

Co-authored-by: Doug Fawley <[email protected]>

Signed-off-by: anurag.ag <[email protected]>

…osal. Adds links, clarifies slow start implementation details, and aligns with linked A24 proposal. Signed-off-by: anurag.ag <[email protected]>

anuragagarwal561994 · 2025-08-29T01:40:13Z

@markdroth I have made the respective changes, let me know if there are more changes required

markdroth

This is looking really good! Only a few comments remaining.

For future reference, please don't force-push to a PR after reviews have started, because that makes it very difficult for a reviewer to tell what's changed since their last review pass.

Please let me know if you have any questions. Thanks!

A100-client-side-weighted-round-robin-slow-start.md

A24-lb-policy-config.md

A100-client-side-weighted-round-robin-slow-start.md

…rmatting, and changes `aggression` type to `double`. Signed-off-by: anurag.ag <[email protected]>

… formatting fixes. Signed-off-by: anurag.ag <[email protected]>

markdroth

Looks great!

anuragagarwal561994 · 2025-08-29T19:36:04Z

@ejona86 @atollena @dfawley can you help me review and approve this proposal?

anuragagarwal561994 marked this pull request as draft May 31, 2025 04:49

anuragagarwal561994 mentioned this pull request May 31, 2025

Support for slow start with WRR Load Balancer Policy grpc/grpc-java#12087

Open

anuragagarwal561994 marked this pull request as ready for review May 31, 2025 05:03

ejona86 requested review from ejona86 and markdroth June 2, 2025 14:20

atollena reviewed Jun 6, 2025

View reviewed changes

client-side-weighted-round-robin-slow-start.md Outdated Show resolved Hide resolved

client-side-weighted-round-robin-slow-start.md Outdated Show resolved Hide resolved

client-side-weighted-round-robin-slow-start.md Outdated Show resolved Hide resolved

anuragagarwal561994 requested a review from atollena June 22, 2025 01:09

atollena reviewed Jul 1, 2025

View reviewed changes

anuragagarwal561994 changed the title ~~Client-side WRR slow start configuration~~ A100: Client-side WRR slow start configuration Jul 1, 2025

anuragagarwal561994 force-pushed the wrrslowstart branch 2 times, most recently from 10be215 to 43b016a Compare July 1, 2025 12:39

This was referenced Jul 1, 2025

proto: Adds slow start config to wrr proto message envoyproxy/envoy#40090

Closed

Slow Start Config support for Client Side WRR envoyproxy/envoy#40091

Closed

anuragagarwal561994 force-pushed the wrrslowstart branch from 0a3ea16 to e490283 Compare July 2, 2025 14:32

anuragagarwal561994 requested a review from atollena July 2, 2025 14:37

anuragagarwal561994 mentioned this pull request Jul 2, 2025

Implementing SlowStartConfig for WRR Load Balancing Policy grpc/grpc-java#12200

Draft

atollena approved these changes Jul 17, 2025

View reviewed changes

A100-client-side-weighted-round-robin-slow-start.md Outdated Show resolved Hide resolved

dfawley reviewed Jul 17, 2025

View reviewed changes

markdroth reviewed Jul 18, 2025

View reviewed changes

anuragagarwal561994 requested review from markdroth and atollena July 20, 2025 10:39

anuragagarwal561994 requested a review from dfawley July 20, 2025 10:39

markdroth reviewed Aug 19, 2025

View reviewed changes

markdroth mentioned this pull request Aug 19, 2025

A101: xDS-Based setting SNI and server certificate SAN validation #507

Open

anuragagarwal561994 and others added 16 commits August 28, 2025 14:06

Adds draft proposal for slow start config

0aa9ba4

Signed-off-by: anurag.ag <[email protected]>

Deletes example

65c3c6d

Signed-off-by: anurag.ag <[email protected]>

Linking proposal

c63fe59

Signed-off-by: anurag.ag <[email protected]>

Linking user

a4a2bbb

Signed-off-by: anurag.ag <[email protected]>

Adds scopes and limitation section

1f39fe7

Signed-off-by: anurag.ag <[email protected]>

Remove dependency from xds proto

8bb3da0

Signed-off-by: anurag.ag <[email protected]>

Updates proposal number to A100

0b603de

Signed-off-by: anurag.ag <[email protected]>

Updates references

6ce237e

Signed-off-by: anurag.ag <[email protected]>

Updates proposal to include ready_since timestamp

c0f6592

Signed-off-by: anurag.ag <[email protected]>

Adds Java Implementation

3de4cfc

Signed-off-by: anurag.ag <[email protected]>

Fix typo, making offers as offer

ed6c9a7

Co-authored-by: Antoine Tollenaere <[email protected]>

Apply suggestions from code review

d92cf99

Co-authored-by: Doug Fawley <[email protected]>

Fixes min_weight_percent nit

15247c9

Updates proposal with slow start metrics and related references

1d363cd

Signed-off-by: anurag.ag <[email protected]>

Updates proposal with experimental metric details and formatting fixes

082fc33

Signed-off-by: anurag.ag <[email protected]>

Fixes formatting inconsistencies and updates terminology in A100 prop…

c346e9a

…osal. Adds links, clarifies slow start implementation details, and aligns with linked A24 proposal. Signed-off-by: anurag.ag <[email protected]>

anuragagarwal561994 force-pushed the wrrslowstart branch from e495afb to c346e9a Compare August 29, 2025 01:38

markdroth reviewed Aug 29, 2025

View reviewed changes

anuragagarwal561994 added 2 commits August 29, 2025 21:24

Aligns A100 proposal with related gRFCs, updates references, fixes fo…

82a4089

…rmatting, and changes `aggression` type to `double`. Signed-off-by: anurag.ag <[email protected]>

Updates A100 proposal with min_weight_percent type change and minor…

c17b3f6

… formatting fixes. Signed-off-by: anurag.ag <[email protected]>

markdroth approved these changes Aug 29, 2025

View reviewed changes


		## Implementation

		This will be implemented in all languages C++, Java, and Go.


		## Metrics

		The following metric will be exposed to help monitor the slow start behavior:

A100: Client-side WRR slow start configuration #498

Are you sure you want to change the base?

A100: Client-side WRR slow start configuration #498

Conversation

anuragagarwal561994 commented May 31, 2025

Uh oh!

ejona86 commented Jun 2, 2025

Uh oh!

anuragagarwal561994 commented Jun 6, 2025

Uh oh!

atollena left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

anuragagarwal561994 commented Jun 6, 2025

Uh oh!

anuragagarwal561994 commented Jun 16, 2025

Uh oh!

anuragagarwal561994 commented Jun 19, 2025

Uh oh!

anuragagarwal561994 commented Jun 30, 2025

Uh oh!

atollena left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

atollena Jul 1, 2025

Choose a reason for hiding this comment

Uh oh!

anuragagarwal561994 Jul 2, 2025

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

anuragagarwal561994 commented Jul 2, 2025

Uh oh!

anuragagarwal561994 commented Jul 7, 2025

Uh oh!

atollena left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

dfawley left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

dfawley Jul 17, 2025

Choose a reason for hiding this comment

Uh oh!

anuragagarwal561994 Jul 18, 2025

Choose a reason for hiding this comment

Uh oh!

anuragagarwal561994 commented Jul 18, 2025

Uh oh!

markdroth left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

anuragagarwal561994 commented Jul 20, 2025