Hi Muelsa, The threads are for the pool in ScheduledExecutorService instance that logback uses internally. See ExecutorServiceUtil.newScheduledExecutorService [1] for the code. The number of threads in the "core" pool is fixed currently at 8. Indeed, if you have 10 web-applications, that makes 80 threads spread through 10 different pools. I think it the pool size should be smaller, especially since new threads can be created if the need be. Can you please create a jira issue asking for a smaller core pool size for logback's internal ScheduledExecutorService instance? Thanks, -- Ceki [1] https://logback.qos.ch/xref/ch/qos/logback/core/util/ExecutorServiceUtil.htm... On 19.01.2018 15:15, Muelsa Prinarnod wrote:

Dear all,

/first of all, excuse me if you receive this issue 2 times, but I've sent it before subscribing and I was not sure it was accepted./

I have deployed 10 applications in Tomcat/Spring and each one contains logback in order to have a different log file for each application.

When I look at tomcat threads, I see 8 threads per application (named logback-1 to logback-8).

Does anyone know why 8 and how to reduce that number ? (and the consequencies) ? 8x10 is much ...

thanks in advance for any help, Samuel