I did some testing around this scenario, and I was also able to export data/mutate schema while concurrent read and writes. I guess the connection refused error was just due to the open file limit. Although I grep-ed the alpha logs just for “error” strings after these operations and found these -
Applying proposal. Error: Pending transactions found. Please retry operation. Proposal: "mutations:<group_id:1 start_ts:41519 schema:<predicate:\"entity_type\" value_type:STRING > schema:<predicate:\"entity_value\" value_type:STRING directive:INDEX tokenizer:\"exact\" tokenizer:\"fulltext\" count:true >
TryAbort 1 txns with start ts. Error: <nil>
TryAbort: No aborts found. Quitting.
tryAbortTransactions for 1 txns. Error: <nil>
When do these logs get published? Is it something I need to worry about?