Previously, when a Servlet-based WebServer was stopped it would also
stop the ServletContext. This led to problems as Tomcat and Undertow
would then not allow a restart. Jetty would allow a restart but
duplicate servlet registrations would then be attempted.
This commit modifies the WebServer lifecycle to separate stopping
and destruction for both servlet and reactive web servers. This
allows a WebServer's stop() implementation to leave some components
running so that they can be restarted. To completely shut down a
WebServer destroy() must now be called.
Both Tomcat and Jetty WebServers have been updated to stop their
network connections when stop() is called but leave other components
running. This works with both servlet and reactive web servers.
Note that an Undertow-based Servlet web server does not support
stop and restart. Once stopped, a Servlet Deployment cannot be
restarted and it does not appear to be possible to separate the
lifecycle of its network connections and a Servlet deployment.
Reactor Netty and Undertow-based reactive web servers can now also
be stopped and then restarted. Calling stop() stops the whole server
but this does not cause a problem as there's no (application-exposed)
ServletContext involved. There may be room to optimize this in the
future if the need arises.
Closes gh-34955
Docs related to gh-33280 (log correlation) and
gh-35593 (application name in each log line) need some polishing:
- Fix project names
- Show how to avoid having the application name duplicated in logs
- Call out that a trailing space is needed in the correlation pattern
Closes gh-36035
See gh-33280
See gh-35593
Update Logback and Log4J2 so that they include the application name on
each log line. If `spring.application.name` had not been set, or if
`logging.include-application-name` is `false` then the name is not
logged.
Closes gh-35593
Add support for logging correlation IDs with Logback or Log4J2 whenever
Micrometer tracing is being used.
The `LoggingSystemProperties` class now accepts a defualt value resolver
which will be used whenever a value isn't in the environment. The
`AbstractLoggingSystem` provides a resolver that supports the
`logging.pattern.correlation` property and will return a value whenever
`LoggingSystem.EXPECT_CORRELATION_ID_PROPERTY` is set.
Using `LoggingSystem.EXPECT_CORRELATION_ID_PROPERTY` allows us to
provide a consistent width for the correlation ID, even when it's
missing from the MDC.
The exact correlation pattern returned will depend on the `LoggingSytem`
implementation. Currently Logback and Log4J2 are supported and both
make use of a custom converter which delegates to a new
`CorrelationIdFormatter` class.
Closes gh-33280
