• several JVM-s per Linux box
• 5 SyslogAppender-s logging to syslog-ng on 127.0.0.1

Once in a while one of the SyslogAppender-s (the busiest one with longest messages) stops logging completely
Other SyslogAppender-ss continue working fine.

/usr/sbin/tcpdump has confirmed upd packets reach
syslog-ng port via 'lo' network interface for remaining appends

/usr/sbin/tcpdump has confirmed NO udp packets reach
syslog-ng port via 'lo' network interface for the failing appender

We have JMX enabled. JConsole does show StatusManager messages.
There are no error messages there.
Just the messages emitted during initial logback configuration
from logback.xml on the classpath.

We had invoked 'reload()' method via JMX.
StatusMananger messages observed via JMX show that reload had happened.
Full re-configuration had happened.
All 5 SyslogAppenders had been apparently re-created.
Yet NO udp messages had come from the SyslogAppender
replacing those which had previously failed.

Reloading did not help at all.