Spanner now supports end-to-end tracing in preview, along with client-side tracing in the Java and Go client libraries

## Feature Spanner now supports end-to-end tracing in preview, along with client-side tracing in the Java and Go client libraries. You can opt-in for end-to-end traces to have more visibility into the application to Spanner latencies. For more information, see [Trace collection overview](https://cloud.google.com/spanner/docs/tracing-overview).