Monitor for server errors

You can use the system.errors table to see all errors that have occured since the ClickHouse server started.

This can be used for monitoring, and is also particularly helpful in a CI process to discover if your changes have introduced new errors.

SELECT *
FROM system.errors

Query id: b0b33ee8-3d69-4206-a76a-0195fdd7d6c3

Row 1:
──────
name:               CANNOT_OPEN_FILE
code:               76
value:              1
last_error_time:    2022-09-23 11:14:27
last_error_message: Cannot open certificate file: /etc/clickhouse-server/server.crt.
last_error_trace:   [411056556,274636808,373796314,373793573,275220227,275089724,275184637,275157606,409980372,275094329,410064590,275084802,192344697,140684615164560,140684615164746,192342254]
remote:             0

Row 2:
──────
name:               NOT_AN_AGGREGATE
code:               215
value:              2
last_error_time:    2022-09-23 11:18:55
last_error_message: Column `_partition_id` is not under aggregate function and not in GROUP BY. Have columns: ['count()']
last_error_trace:   [411056556,274636808,196780545,354757704,354786429,354664707,354594247,354633905,354651659,359523047,359498339,359480912,359471762,359489150,370718129,370733171,359522916,359498339,359480912,359472098,359772417,359765631,359212706,359209076,362345720,362336958,373947906,374012298,409906599,409907866,411477979,411468053]
remote:             0

2 rows in set. Elapsed: 0.001 sec.