When full output buffers stall the pipeline, we log a message: "pipeline stalled {} seconds because output buffers are full". @lalithsuresh suggests that we should log the more helpful message: "pipeline stalled {} seconds because output buffers from connector {connector-name} are full (observed output throughput is {} records/second). Pleases tune the output connector or downstream data destination for higher throughputs."

See #5170 (comment)