TransportChannelProvider bean overwrites maxInboundMetadataSize with null

[ivan-zaitsev]

Describe the bug
TransportChannelProvider bean overwrites maxInboundMetadataSize with null by not setting it. It causes io.grpc.netty.shaded.io.netty.handler.codec.http2.Http2Exception: Header size exceeded max allowed size (10240) error because it fallbacks to default 10KiB instead of 4MiB.

Sample
The library has default 4MB:
https://github.com/googleapis/java-pubsub/blob/main/google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Subscriber.java#L487

[diegomarquezp]

Hi @ivan-zaitsev, thanks for reporting this issue. Would you mind sharing how you are using the bean and any properties file you are working with? Thanks!

@burkedavison @meltsufin shouldn't a config file override this default setting?

[ivan-zaitsev]

Hello @diegomarquezp, default config, default bean.

spring:
  cloud:
    gcp:
      project-id: ...
      credentials:
        encoded-key: ...

You can trace bean TransportChannelProvider usage and will find that it will have maxInboundMetadataSize set to null. It will eventually overwrite it here. But default TransportChannelProvider has that value set to 4MiB.

By some reason SubscriberStubSettings.defaultGrpcTransportProviderBuilder() only sets maxInboundMessageSize.

[meltsufin]

@diegomarquezp I agree that we should keep the defaults set by Pub/Sub, unless they are overwritten by configuration or we intentionally want to change them in Spring Cloud GCP. In this particular case, we are unintentionally overriding the defaults and should fix it.