Observe async insert errors during buffer flushes

Flush_Errors.sql

WITH
    'default' AS db_name,
    'upclick_metrics' AS table_name,
    10 as last_x_minutes
 SELECT
    DENSE_RANK() OVER(ORDER BY hostName()) AS n,
    max(event_time) AS flush,
    status,
    exception,
    any(query_id) AS query_id
 FROM
    clusterAllReplicas(default, system.asynchronous_insert_log)
WHERE
    status <> 'Ok'
    AND database = db_name AND table = table_name
    AND event_time > now() - toIntervalMinute(last_x_minutes)
GROUP BY hostName(), status, exception
ORDER BY
    hostName(), flush DESC;