ClickHouse log levels

[Den Gribkov]

Hello,

Unfortunately I didn't find such info in official documentation.

Could you please explain which levels could be used for ClickHouse logger?
By default it configured like:

        <logger>
                <level>trace</level>
                <log>/var/log/clickhouse-server/clickhouse-server.log</log>
                <errorlog>/var/log/clickhouse-server/clickhouse-server.err.log</errorlog>
                <size>1000M</size>
                <count>10</count>
        </logger>

and generates huge number of messages on high loaded server.

Thank you.

[man...@gmail.com]

Hello.

Log levels are trace, debug, information, warning, error (in decreasing verbosity).
Using 'trace' log level (by default) usually doesn't have much impact on performance, but size of log files are indeed large.
If it is not suitable for you, switch log level to 'debug'.

I not recommend to use 'warning' or 'error' log levels, because too much information is lost.

By the way, If there are too much log messages, it is worth to check, you does not insert data in too small batches (one second batches or more is recommended).
Also, it is worth to look, what exactly log messages are generated. If you don't need log messages with '<Trace>' substring, switch log level to 'debug' and so on.

[tdingus]

Hi, 

After clickhouse-server has started, I don't see any log file generated:/var/log/clickhouse-server/clickhouse-server.log

Do I need to do anything to enable the logging?

Thanks