Re: ListAppender in parallel tests

The main reason why ListAppender doesn't support concurrent tests is
essentially a chicken-or-the-egg scenario. While I'd love to be able
to enable concurrent tests in log4j-core, for example, there are so
many tests that aren't currently configured or written to work
concurrently, nobody got around to implementing concurrency support in
ListAppender to support such a use case. Updates to ListAppender (or
an additional appender supporting concurrency) would certainly be
welcomed as contributions!

On Wed, Apr 13, 2022 at 10:46 AM Björn Kautler <[email protected]> wrote:
>
> Hi
>
> I'm currently using ListAppender from log4j2-core-test, to test that
> the logging of the project does what it should do.
> For that I configured a ListAppender in the log4j2 config file that is
> used for the tests.
> In a custom global Spock extension (the test framework I use), I
> retrieve the appender
> using ListAppender.getListAppender and call clear() on it before an
> iteration starts,
> so I only get the logs written during that test and it also does not
> overflow the RAM.
>
> Now my problem is, that I'd like to enable parallel execution of the
> tests which is new in Spock 2.x.
> But the ListAppender naturally does not like that, as it is the same
> for the whole JVM.
>
> I looked into the LoggerContextRule whether I find something useful there,
> but - please correct me if I'm wrong - as far as I have seen it also
> is not capable of parallel execution
> as it uses system properties and static state, so parallel tests would
> also overwrite each other I guess.
>
> Is there something that could be used that better supports parallel execution?
> Would maybe a ThreadLocalListAppender help that has thread local
> fields for events, messages, and data?
> Or something else that is available?
>
> Regards
> Björn
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: [email protected]
> For additional commands, e-mail: [email protected]
>