How to disable Stack Trace in Confluence Log

[Benjamin W_]

Hello folks

in order to take care of issues with our Confluence installation (on Prem, 6.14.2) I want to get rid of unnecessary information in the log files. (e.g. Application Data\Confluence\logs\atlassian-confluence.log)

Especially the Stack Traces in the default extend are - in my point of view - not relevant for a system admin. On error in the log file generates up to 320 lines of stack trace. This makes the log very hard to read and analyze.

I have tried changing the parameters in the log4j.properties, but this has no impact on the stack trace itself, only on the items that occure in the log themselves.

I have searched the Web for a solution, but apart from a similiar question from 2016 in the community I was not able to find an answer. https://community.atlassian.com/t5/Confluence-questions/Disable-Stacktrace-information/qaq-p/318306

Therefor: how can the stack trace be reduced from 320 lines to e.g. five lines?

Thanks and regards, Benjamin

[Thomas Deiler]

Dear @Benjamin W_ ,

have a look at this external article. It describes this in general for log4j - not specially for Confluence.

So long

Thomas

[Benjamin W_]

Hello @Thomas Deiler 

thank you very much for your fast feedback.

I followed on your hint regarding %throwable{n}. This exactly seems to do what I am looking for!
Unfortunately, I was not able to get this working as expected. From my understanding, %throwable{n} is falsely getting interpreted as %t, which refers to the causing Thread.

Step by step:

in log4j.properties I have enriched all the lines with ConversionPattern with %throwable{3}. So e.g.
log4j.appender.confluencelog.layout.ConversionPattern=%d %p [%c{4}] %M %m%n %throwable{3}

The stack trace is still shown at full extend.

I realized that the log is showing localhost-startStop-1hrowable{3} which leads to my assumption that it is getting interpreted as %t + plain String hrowable{3}

I have tried the following variants, but all none with the expected result:
- surrounded with square brackets [%throwable{3}] (in order to make this a "single" statement)
- removed %t (in order to avoid conflict)
- put to the beginning of the ConversionPattern (before %d, in order to have this parsed first)
- instead of %throwable{3} use %throwable{short} (any other documented option instead of number)
- same for %throwable{none} (reason why see below)

From the official documentation, this option %throwable{n} is supported since log4j 1.2.16. I have verified that our Confluence installation has log4j-1.2.17.jar, which is also the latest release of log4j 1.x (stated here https://logging.apache.org/log4j/1.2/download.html)

Interestingly, I found a discussion in the Jira Community dealing with Jira logs and Syslog-Server. (see here https://community.atlassian.com/t5/Jira-questions/Push-JIRA-logs-to-syslog-server/qaq-p/458074)
The explanations there contain the usage of %throwable{none}. 
So the usage of this parameter within the Atlassian universe seems to be common.
I have tried using %throwable{none}, but same result..

Am I missing something?

Thanks and Regards, Benjamin

[Thomas Deiler]

Dear @Benjamin W_ ,

I am not fit enough any more for the details of Log4j. So please ask this specific question at https://community.developer.atlassian.com/ again.

So long

Thomas

[Benjamin W_]

Thanks for the suggestion - was not aware of this community.

Have placed it there. See here

Keep you posted.

[Kurt Rosivatz]

I found a possible solution and posted it in the developer community and now here:

I got it to work so far, but did not dare to use it in production ...

Im using Confluence Server 7.4 LTS, in my log4j.properties, there is the line:

`log4j.appender.confluencelog.layout=com.atlassian.confluence.util.PatternLayoutWithContext`

It seems that Atlassians PatternLayoutWithContext does not support the %throwable Parameter for the layout. But org.apache.log4j.EnhancedPatternLayout does. So I changed the line to:

`log4j.appender.confluencelog.layout=org.apache.log4j.EnhancedPatternLayout`

And layout to:

`log4j.appender.confluencelog.layout.ConversionPattern=%d %p [%t] [%c{4}] %M %m%n %throwable{1}`

And that works fine - no long stack traces any more in the log files.

Regards,
Kurt