Stomp queue restructuring for mass scalability:

- Multiplexing queues into groups and for multiple sites.
- Sharing vs breakout configurable per site and per queue via $config['queue']['breakout']
- Detect how many times a message is redelivered, discard if it's killed too many daemons
 - count configurable with $config['queue']['max_retries']
 - can dump the items to files in $config['queue']['dead_letter_dir']

Queue daemon memory & resource leak fixes:
- avoid unnecessary reconnections to memcached server (switch persistent connections back in on second initialization, assuming it's child process)
- monkey-patch for leaky .ini loads in DB_DataObject::databaseStructure() - was leaking 200k per active switch
- applied leak fixes to Status_network as well, using intermediate base Safe_DataObject for both it and Memcache_DataObject

Misc queue fixes:
- correct handling of child processes exiting due to signal termination instead of regular exit
- shutdown instead of infinite respawn loop if we're already past the soft memory limit at startup
- Added --all option for xmppdaemon... still opens one xmpp connection per site that has xmpp active

Cache updates:
- add Cache::increment() method with native support for memcached atomic increment

1 files changed, 7 insertions, 1 deletions

diff --git a/lib/default.php b/lib/default.php
index bf4b83718..a74cccae1 100644
--- a/lib/default.php
+++ b/lib/default.php
@@ -81,7 +81,7 @@ $default =
               'subsystem' => 'db', # default to database, or 'stomp'
               'stomp_server' => null,
               'queue_basename' => '/queue/statusnet/',
-              'control_channel' => '/topic/statusnet-control', // broadcasts to all queue daemons
+              'control_channel' => '/topic/statusnet/control', // broadcasts to all queue daemons
               'stomp_username' => null,
               'stomp_password' => null,
               'stomp_persistent' => true, // keep items across queue server restart, if persistence is enabled
@@ -91,6 +91,12 @@ $default =
               'spawndelay' => 1, // Wait at least N seconds between (re)spawns of child processes to avoid slamming the queue server with subscription startup
               'debug_memory' => false, // true to spit memory usage to log
               'inboxes' => true, // true to do inbox distribution & output queueing from in background via 'distrib' queue
+              'breakout' => array('*' => 'shared'), // set global or per-handler queue breakout
+                                      // 'shared': use a shared queue for all sites
+                                      // 'handler': share each/this handler over multiple sites
+                                      // 'site': break out for each/this handler on this site
+              'max_retries' => 10, // drop messages after N failed attempts to process (Stomp)
+              'dead_letter_dir' => false, // set to directory to save dropped messages into (Stomp)
               ),
         'license' =>
         array('type' => 'cc', # can be 'cc', 'allrightsreserved', 'private'