Alternatives to HTTP API?

Are there more intimate APIs to stream data to Influx? More connection-oriented/non-textual APIs? At high data volumes, it would seem that the HTTP overhead and parsing overhead could be substantial and limiting, particularly in real world IoT use cases.

In Telegraf, metrics are batched with a default batch size of 1000, the HTTP overhead is relatively minor in this case. If you need additional performance you can also send over UDP.