Traditional-format messages have these fields: 

time thread [label] [err_code] [subsystem] msg 

The [  and ]  square bracket characters are literal characters in the message format. They do not indicate that fields are optional. 

The label  value corresponds to the string form of the prio  error event priority field. 

The [err_code]  and [subsystem]  fields were added in MySQL 8.0. They are missing from logs generated by older servers. Log parsers can treat these fields as parts of the message text that is present only for logs written by servers recent enough to include them. Parsers must treat the err_code  part of [err_code]  indicators as a string value, not a number, because values such as MY-012487  and MY-010051  contain nonnumeric characters. 

## log_sink_json Output Format 

The JSON-format log sink produces messages as JSON objects that contain key-value pairs. For example: 

{ "prio": 3, "err_code": 10051, "source_line": 561, "source_file": "event_scheduler.cc", "function": "run", "msg": "Event Scheduler: scheduler thread started with id 5", "time": "2020-08-06T14:25:03.109022Z", "ts": 1596724012005, "thread": 5, "err_symbol": "ER_SCHEDULER_STARTED", "SQL_state": "HY000", "subsystem": "Server", "buffered": 1596723903109022, "label": "Note" } 

The message shown is reformatted for readability. Events written to the error log appear one message per line. 

The ts  (timestamp) key was added in MySQL 8.0.20 and is unique to the JSON-format log sink. The value is an integer indicating milliseconds since the epoch ( ’1970-01-01 00:00:00’  UTC). 

The ts  and buffered  values are Unix timestamp values and can be converted using FROM_UNIXTIME() and an appropriate divisor: 

## log_sink_syseventlog Output Format 

mysql> SET time_zone = ’+00:00’; mysql> SELECT FROM_UNIXTIME(1596724012005/1000.0); +-------------------------------------+ | FROM_UNIXTIME(1596724012005/1000.0) | +-------------------------------------+ | 2020-08-06 14:26:52.0050 | +-------------------------------------+ mysql> SELECT FROM_UNIXTIME(1596723903109022/1000000.0); +-------------------------------------------+ | FROM_UNIXTIME(1596723903109022/1000000.0) | +-------------------------------------------+ | 2020-08-06 14:25:03.1090 | +-------------------------------------------+ 

The system log sink produces output that conforms to the system log format used on the local platform. 

