OTLP requires clients to honor server-requested throttling and retry logic. See protocol specification:

• Result code - https://github.com/open-telemetry/oteps/blob/master/text/0035-opentelemetry-protocol.md#result-code
• Throttling - https://github.com/open-telemetry/oteps/blob/master/text/0035-opentelemetry-protocol.md#throttling

We also have an ongoing PR that changes how exactly this information is conveyed in the response: open-telemetry/oteps#65

I do not see this handled anywhere in the exporter code. If it is handled please point me to the appropriate place in the code and close this issue.