MRG: how to change logging of qpidd

Environment

• MRG Messaging (any version)

Issue

• How can I change verbosity and areas to be logged by qpid broker?

Resolution

• Use --log-enable option with syntax:

--log-enable LEVEL[+][:PATTERN]

when running qpidd from command line, or

log-enable=LEVEL[+][:PATTERN]

when using configuration file. Note that command line option precedes configuration file option - see this solution for details.

• LEVEL is one of: trace debug info notice warning error critical
• The "+" means log the given severity and any higher severity (without the plus, logging of the given severity only will be enabled)
• PATTERN is the scope of the logging change.
  • The string in PATTERN is matched against the fully-qualified name of the C++ function with the logging statement.
    • To see the fully-qualified name of the C++ function with the logging statement, either check source code or add to qpid configuration log-function=yes option and force qpid broker to log such message
  • So e.g. --log-enable debug+:cluster matches everything in the qpid::cluster module, while e.g. --log-enable debug+:broker::Queue::consumeNextMessage will enable logging of one particular method only (the consumeNextMessage method in the given namespace in this example).
  • PATTERN is often set to the module one needs to debug, like acl, amqp_0_10, broker, cluster, management or store.
• The option can be used multiple times.
• Be aware that having just one option like "log-enable=debug+:cluster" enables debug logs of cluster stuff, but does not produce any other logs; to add some more verbose logging, one should add such option like the above plus "artificially" add there the default value:

log-enable=notice+

• To change logging verbosity of a running broker without the necessity to restart it, follow this solution.

Diagnostic Steps

• Examples of adding some verbose logs (qpidd running from command line, while in qpid-stat -q is executed in another terminal):

$ qpidd --log-enable=debug+:SessionState::SessionState --log-enable=debug+:SessionState::detach
2013-10-25 11:34:59 [Broker] debug SessionState::SessionState anonymous.0aa2d72c-c7a6-496a-9418-5c4647e61611:0: 0x7f23740457f0
2013-10-25 11:34:59 [Broker] debug anonymous.0aa2d72c-c7a6-496a-9418-5c4647e61611:0: detached on broker.
^C
$

• The above logging prints out session attachment event (QPID_LOG macro called in SessionState constructor) and session detaching event. But the logging lacks any other log, despite of critical verbosity. To print out also default logging, let add --log-enable=notice+:

$ qpidd --log-enable=debug+:SessionState::SessionState --log-enable=debug+:SessionState::detach --log-enable=notice+
2013-10-25 11:35:26 [Broker] notice SASL disabled: No Authentication Performed
2013-10-25 11:35:26 [Network] notice Listening on TCP/TCP6 port 5672
2013-10-25 11:35:26 [Security] notice SSL plugin not enabled, you must set --ssl-cert-db to enable it.
2013-10-25 11:35:26 [Broker] notice Broker running
2013-10-25 11:35:29 [Broker] debug SessionState::SessionState anonymous.fabe325f-d613-4320-9d11-6503e95a278d:0: 0x7f78f0004a90
2013-10-25 11:35:29 [Broker] debug anonymous.fabe325f-d613-4320-9d11-6503e95a278d:0: detached on broker.
^C2013-10-25 11:35:31 [Broker] notice Shut down
$

• To see all logs related to a connection, let use:

$ qpidd --log-enable=trace+:Connection --log-enable=notice+2013-10-25 11:38:29 [Broker] notice SASL disabled: No Authentication Performed
2013-10-25 11:38:29 [Network] notice Listening on TCP/TCP6 port 5672
2013-10-25 11:38:29 [Security] notice SSL plugin not enabled, you must set --ssl-cert-db to enable it.
2013-10-25 11:38:29 [Broker] notice Broker running
2013-10-25 11:38:32 [Broker] debug LinkRegistry::notifyConnection(); key=127.0.0.1:5672-127.0.0.1:51750
2013-10-25 11:38:32 [Model] trace Mgmt create connection. id:127.0.0.1:5672-127.0.0.1:51750
2013-10-25 11:38:32 [Protocol] trace SENT [127.0.0.1:5672-127.0.0.1:51750]: INIT(0-10)
..
2013-10-25 11:38:32 [Model] debug Delete connection. user:anonymous rhost:127.0.0.1:5672-127.0.0.1:51750
2013-10-25 11:38:39 [Model] trace Mgmt delete connection. id:127.0.0.1:5672-127.0.0.1:51750 Statistics: {bytesFromClient:1128, bytesToClient:2327, closing:False, framesFromClient:18, framesToClient:17, msgsFromClient:1, msgsToClient:1}
^C2013-10-25 11:38:44 [Broker] notice Shut down
$

• See the excessive number of log records just after enabling trace logs from one area.

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