'stomp_username' => null,
'stomp_password' => null,
'stomp_persistent' => true, // keep items across queue server restart, if persistence is enabled
+ 'stomp_transactions' => true, // use STOMP transactions to aid in detecting failures (supported by ActiveMQ, but not by all)
+ 'stomp_acks' => true, // send acknowledgements after successful processing (supported by ActiveMQ, but not by all)
'stomp_manual_failover' => true, // if multiple servers are listed, treat them as separate (enqueue on one randomly, listen on all)
'monitor' => null, // URL to monitor ping endpoint (work in progress)
'softlimit' => '90%', // total size or % of memory_limit at which to restart queue threads gracefully