Replication queue
SELECT
database,
table,
type,
max(last_exception),
max(postpone_reason),
min(create_time),
max(last_attempt_time),
max(last_postpone_time),
max(num_postponed) AS max_postponed,
max(num_tries) AS max_tries,
min(num_tries) AS min_tries,
countIf(last_exception != '') AS count_err,
countIf(num_postponed > 0) AS count_postponed,
countIf(is_currently_executing) AS count_executing,
count() AS count_all
FROM system.replication_queue
GROUP BY
database,
table,
type
ORDER BY count_all DESC