Thank you both for the responses.
You asked for the log4j configuration.
I try to extract the relevant parts.
Indeed the application has got a DynamicThresholdFilter in the game.
<DynamicThresholdFilter key="abc" onMatch="ACCEPT" onMismatch="DENY">
<KeyValuePair key="abc" value="INFO" />
</DynamicThresholdFilter>
There two appenders referenced from the loggers, one usual RollingFile appender
with the following pattern:
<Pattern>%d{yyyy-MM-dd HH:mm:ss,SSS 'UTC'Z} %-5p [%t] (%X{reqtype})
[%X{reqtag}] %c -- %m%n</Pattern>
And one Null appender as placeholder.
The loggers are configured to INFO, that's why just the two lines.
They have no extra threshold configured.
If I remove the (%X{reqtype}) [%X{reqtag}], then this doesn't improve the
performance.
But indeed, if I remove the DynamicThresholdFilter, then the performance is
back at normal, if loggers remain on INFO.
I didn't test with DEBUG enabled, and haven't got figures to compare.
