lightning report "received message larger than max (18552234 vs. 4194304)" during duplicate resolution

[D3Hunter]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

currently, we use default max-message-size which is 4M, see

tidb/pkg/lightning/backend/local/local.go

Line 144 in bda79ca

func (f *importClientFactoryImpl) makeConn(ctx context.Context, storeID uint64) (*grpc.ClientConn, error) {

2. What did you expect to see? (Required)

no error

3. What did you see instead (Required)

err

4. What is your TiDB version? (Required)

8.1.0

[D3Hunter]

tikv send max 4k KV on each response. each KV is about 4K+ in the issue case
https://github.com/tikv/tikv/blob/076b79c54b9e7656f9119865d4ed75bec3bd58d6/src/import/duplicate_detect.rs#L16

[fishiu]

/assign