Hi Tibor,
Your analysis makes sense. As SimpleLogger acts as an appender as found
in log4j/logback backends, SimpleLogger should cater for concurrent
access with some sort of synchronization. It currently does not.
Please create a jira issue for this problem.
Best regards,
--
Ceki Gülcü
On 08.07.2021 15:23, Tibor Digaňa wrote:
Hi Ceki,
We have observed a strange behavior of the logger slf4j-simple when two
or more parallel Maven modules log the exceptions and the messages.
It produces corrupted lines in the log and they are partially mixed with
other lines.
The lines look like this and they are obviously not expected in the log.
[ERROR] R] *********.util.json.formatter.JsonFormatterTest
[ERROR] Process Exit Code: 0
[ERROR] *********.util.json.formatter.JsonFormatterTest
After our analysis we found the place in SLF4J code which seems to be
the root cause.
The method [1] is a critical section and must be synchronized with a
singleton lock which avoids reordering of the nested method calls across
multiple Threads. Without it, the normal messages and stack trace may
mix especially if two parallel Maven modules print the stacktrace.
[1]:
https://github.com/qos-ch/slf4j/blob/39e3b81e5ea69c6610c8d5fd57fd974e090d9fc1/slf4j-simple/src/main/java/org/slf4j/simple/SimpleLogger.java#L243
<https://github.com/qos-ch/slf4j/blob/39e3b81e5ea69c6610c8d5fd57fd974e090d9fc1/slf4j-simple/src/main/java/org/slf4j/simple/SimpleLogger.java#L243>
Pls analyse the class SimpleLogger.java and answer with your opinion
about this issue and a proposal with the fix.
If there are more other critical sections which need to have some
concurrency treatments, we can talk about it in this mailing list.
--
Cheers
Tibor
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
