This page last changed on Jul 30, 2009 by ritchiem.

Technical Specification

Overview

This technical specification page will detail four areas of work to complete the Status Update change:

  • The new classes required
  • How to provide fixed log messages
  • The additions to existing classes
  • The deletions from existing classes

New classes

The new classes required draws on the design work already completed. The abstraction layer will be the new code created as part of this work. This can be split in to Interfaces and Classes.

Interface list

These interfaces form the abstraction layer.

Interface Description
LogActor Actor that will perform the logging.
LogSubject Subject of the logging .
LogMessage Factory to generate LogMessages.
RootMessageLogger Root logger that performs logging.
RawMessageLogger Wrapper for object that actually performs the logging.

Class List

Implementation of the Actors
Class Description
AMQPActor Responsible for providing data about the Connection when logging.
ManagementActor Responsible for providing data about the Management Connection when logging.
Implementation of the LogSubject

Each of these LogSubjects will ensure they toString according to the format design.

Class Description
ConnectionLogSubject Logger responsible for the Connection format.
ChannelLogSubject Logger responsible for the Channel format.
QueueLogSubject Logger responsible for the Queue format.
ExchangeLogSubject Logger responsible for the Exchange format.
BindingLogSubject Logger responsible for the Binding format.
SubscriptionLogSubject Logger responsible for the subscription format.
MessageStoreLogSubject Logger responsible for the MessageStore format.
RootMessageLoggerImpl Base logger that performs the final message formatting before logging.
LogMessageFactoryImpl Factory to create the LogMessages.
Logging
Class Description
Log4jRawMessageLogger Wrapper to use log4j as the output mechanism.
TestRawMessageLogger Wrapper that provides an inspectable log for testing.
Log Messages
Class Description
BrokerLogMessages A static class that contains accessors to the various parametrised log messages.

Psuedo-Code Example


// logActor is retreived from the ThreadLocal
// a logMessage of type logMessage (with parms) is then requested for the specified subject.
logActor.logMessage(logSubject, LogMessage(parms))

...
instance of LogActor{

RootLogger logger = ...getRootLogger();L

  public void logMessage(LogSubject subject, LogMessage message)
  {
     if (logger.isMessageEnabled(this, subject)
     {
        // FormatMessage in to :
        // MESSAGE [ this.toString() ] [ subject.toString() ] <messageID> : <message value>
        logger.logMessage(FormatMessage(this, subject, message));
     }	
  }
}

How to provide fixed log messages

The design calls for providing a fixed method of accessing the messages. Such as the following

String version="0.6";
int build=794277;
String message = BrokerLogMessages.BRK-1001(version, build);

The value of message above would be

BRK-1001 : Startup : Version: 0.6 Build: 794277

This can be done easily with the use of a MessageFormatter and a property file.

BRK-1001 = Startup : Version {0} Build: {1}

Initially the BrokerLogMessages class could be hand coded but in a future iteration it could be generated based on the content of the property file.

Additions to existing classes

The following classes will have logging added to provide the required log messages specified in the Functional Specification.

Main

BRK-1001 : Startup : Version: <Version> Build: <Build>
BRK-1004 : Ready
BRK-1007 : Using logging configuration : <path>

ApplicationRegistry

BRK-1002 : Starting : Listening on <Transport> port <Port>
BRK-1003 : Shuting down : <Transport> port <Port>
BRK-1005 : Stopped

ConfigurationFileApplicationRegistry

BRK-1006 : Using configuration : <path>

JMXManagedObjectRegistry

MNG-1001 : Startup
MNG-1002 : Starting : <service> : Listening on port <Port>
MNG-1003 : Shuting down : <service> : port <Port>
MNG-1004 : Ready
MNG-1005 : Stopped
MNG-1006 : Using SSL Keystore : <path>

VirtualHost

VHT-1001 : Created : <name>
VHT-1002 : Closed

DerbyMessageStore/MemoryMessageStore

MST-1001 : Created : <name>
MST-1003 : Closed

DerbyMessageStore

MST-1002 : Store location : <path>
MST-1004 : Recovery Start [: <queue.name>]
MST-1005 : Recovered <count> messages for queue <queue.name>
MST-1006 : Recovery Complete [: <queue.name>]

AMQMinaProtocolSession

CON-1001 : Open : Client ID <id> : Protocol Version : <version>
CON-1002 : Close

AMQChannel

CHN-1001 : Create : Prefetch <count>
CHN-1002 : Flow <value>
CHN-1003 : Close

QueueRegistry

QUE-1001 : Create : [AutoDelete] [Durable|Transient] [Priority:<levels>] Owner:<name>
QUE-1002 : Deleted

AbstractExchange

EXH-1001 : Create : [Durable] Type:<value> Name:<value>
EXH-1002 : Deleted

ExchangeBindings

BND-1001 : Create [: Arguments : <key=value>]
BND-1002 : Deleted

SubscriptionImpl

SUB-1001 : Create : [Durable] [Arguments : <key=value>]
SUB-1002 : Close

Deletions from existing classes

The following log statements should be removed from the broker packages as they are being replaced with a new message.

AMQMinaProtocolSession

_logger.info("Channel[" + channelId + "] awaiting closure - processing close-ok");
_logger.info("Closing channel due to: " + e.getMessage());
_logger.info("Closing connection due to: " + e.getMessage());
_logger.info("Closing connection due to: " + e.getMessage());
_logger.debug("REALLY Closing protocol session:" + _minaProtocolSession);

AMQPFastProtocolHandler

_logger.info("Protocol session created for:" + protocolSession.getRemoteAddress());
_logger.info("Session opened for:" + protocolSession.getRemoteAddress());
_logger.info("Protocol Session closed for:" + protocolSession.getRemoteAddress());
_logger.debug("AMQPFastProtocolHandler created");

BasicConsumeMethodHandler

_logger.debug("BasicConsume: from '" + body.getQueue() +
_logger.debug("No queue for '" + body.getQueue() + "'");
_logger.debug("Closing connection due to invalid selector");

ChannelFlowHandler.java:

_logger.debug("Channel.Flow for channel " + channelId + ", active=" + body.getActive());

Configuration

_devlog.info("Configuring logger using configuration file " + logConfigFile.getAbsolutePath());
_devlog.info("log file " + logConfigFile.getAbsolutePath() + " will be checked for changes every 
_devlog.debug("Using configuration file " + _configFile.getAbsolutePath());
ex.getMessage());

ConnectionCloseMethodHandler

_logger.info("ConnectionClose received with reply code/reply text " + body.getReplyText() + " for " + session);

DerbyMessageStore

_logger.info("Configuring Derby message store for virtual host " + virtualHost.getName());
       _logger.info("Recovering persistent state...");
_logger.info("Persistent state recovered successfully");
_logger.info("Recovering durable exchange " + exchange.getName() + " of type " + exchange.getType() + "...");
_logger.info("Restoring binding: (Exchange: " + exchange.getName() + ", Queue: " + queueName
_logger.info("Recovered message counts: " + queueRecoveries);
_logger.debug("public void createQueue(AMQQueue queue = " + queue + "): called");
_logger.debug("public void removeQueue(AMQShortString name = " + name + "): called");
_logger.debug("On recovery, delivering " + message.getMessageId() + " to " + queue.getName());

HeadersExchange

_logger.debug("Exchange " + getName() + ": Unbinding " + queue.getName());
_logger.debug("Exchange " + getName() + ": routing message with headers " + headers);

JMXManagedObjectRegistry

log.info("Initialising managed object registry using platform MBean server");
_log.info("JMX ConnectorServer using SSL keystore file " + ksf.getAbsolutePath());
_startupLog.info("JMX ConnectorServer using SSL keystore file " + ksf.getAbsolutePath());

Main

_brokerLogger.info("Starting Qpid Broker " + QpidProperties.getReleaseVersion()
_brokerLogger.info("Qpid.AMQP listening on non-SSL address " + bindAddress);
_brokerLogger.info("Qpid.AMQP listening on SSL port " + config.getSSLPort());
_brokerLogger.info("Qpid Broker Ready :" + QpidProperties.getReleaseVersion()

MemoryMessageStore

_log.info("Using capacity " + DEFAULT_HASHTABLE_CAPACITY + " for hash tables");
_log.info("Using capacity " + hashtableCapacity + " for hash tables");

QueueBindHandler

_log.info("Binding queue " + queue + " to exchange " + exch + " with routing key " + routingKey);

QueueDeclareHandler

_logger.info("Queue " + queueName + " bound to default exchange(" + defaultExchange.getName() + ")");
_logger.info("Queue " + queueName + " declared successfully");

QueueUnbindHandler

_log.info("Binding queue " + queue + " to exchange " + exch + " with routing key " + routingKey);

SimpleAMQQueue

_logger.info("Auto-deleteing queue:" + this);

SubscriptionImpl

_logger.info("Closing subscription (" + debugIdentity() + "):" + this);

VirtualHost

_logger.info("Binding queue:" + queue + " with routing key '" + routingKey + "' to exchange:" + this);
_logger.debug("Loading configuration for virtualhost: " + config.getName());

Feedback

ID From Comment Response
1 Marnie Ensure data logged in messaged due to be deleted is not lost.  
2 Marnie Following 1: Exception handling messages need further thought as replacing with 'Close' messages loses the cause  
3 Marnie Be mindful of performance in generating these log messages  
4 Marnie It is not clear that the LogActors, LogSubjects will be created and attached to their repective model objects  
Document generated by Confluence on May 26, 2010 10:32