I try to setup the Flume appender with type 'Persistent'
However, debug log always tells my FlumeAppender[type="null"...]
After tracking the code, I found at JsonConfiguration#processAttributes line:237 (the super class of YamlConfiguration).
While invoking processAttributes, the attribute 'type' will be filtered out.
I haven't dug out the reason and in what case the attribute 'type' needs to be filtered out, but I think this might accidentally mass up appenders' configuration.