gRPC-Java 1.15.1 发布了 。官方建议 OkHttp 用户进行升级，但如果没有看到下面提到的特定错误，那么应该不会受到太大影响。
- okhttp: settings acks back after apply settings before sending any data. Fixes #4809. If you are seeing “INTERNAL: Flow control error\nRst Stream”, then you were likely impacted.
- core: DnsNameResolver now caches SRV results. Fixes #4745. This makes it “safe” to experiment with
-Dio.grpc.internal.DnsNameResolverProvider.enable_grpclb=true, which will become the default in the future. We encourage users to try out the option and report back issues, especially additional connecting latency, to #4898.