This object is available since 7.5.3. It permits to specify parameters for the main message queue. Note that only queue-parameters are permitted for this config object. This permits to set the same options like in ruleset and action queues. A special statement is needed for the main queue, because it is a different object and cannot be configured via any other object.
Note that when the main_queue() object is configured, the legacy $MainMsgQ...
statements are ignored.
main_queue(
queue.size="100000" # how many messages (messages, not bytes!) to hold in memory
queue.type="LinkedList" # allocate memory dynamically for the queue. Better for handling spikes