Logging

Adeptia Connect logs messages during the execution of a service (for example, a Process Flow) to help you monitor and troubleshoot the application. Message logging is done at four levels: ERROR, NOTICE, INFO, and DEBUG. The NOTICE log level captures all the notable events in the application including the error messages. For example, the Cluster and Queue Processor component log messages at the NOTICE log level. 

The following sections describe the types of logging, benefits and constraints, format of log messages, logging configuration, and configurable properties.

There are two types of logging that Adeptia Connect supports. 

• Synchronous logging
• Asynchronous logging

Synchronous logging

In Synchronous logging, the application logs the messages as and when there is one to be logged and execution of the service is put on hold until the complete message is written in the log. For example, If there are three error messages generated during a Process Flow execution, the execution proceeds to the next stage only after these three error messages are logged. The same execution thread is used for logging also which leads to a stalled execution of the service for the time while the messages are being logged.

Asynchronous logging

In Asynchronous logging, the logging happens in a thread that is separate from the service execution thread. This leads to an uninterrupted execution of the service as it does not need to wait for the logging to be completed. An effective logging mechanism depends on two key factors, low latency and maximum throughput. 

• Latency: Time taken for performing the action and producing the result. 
• Throughput: The number of actions executed per unit of time.
  
  

Benefits and constraints of Asynchronous logging

Asynchronous logging benefits a user in terms of achieving lower latency and maximum throughput. 

• Maximum throughput: With an asynchronous logger, it can log messages at a higher rate in comparison to synchronous logger.
• Lower latency: As the logging occurs in a separate thread, it significantly lowers the latency to the minimum in the overall execution of the service.

Although asynchronous logging can give significant performance benefits, it has the following limitations to take into account:

• In case of an abrupt shutdown which is a rare scenario, the log messages get lost if they are present in the async queue and have not been already logged.
  

  In case of graceful shutdown, Adeptia Connect implements a shutdown hook to ensure that all logs in the queue are logged before bringing the application down.
• In case of a vast number of messages to be logged, the log may display the messages with a delay or after the execution of the service.

Format of log messages

The actual message in the log is accompanied by several other useful information. All the information in the logs is stored in key-value pair format. Storing the information in key-value pair format in the logs has its advantage – the mapped key-value pattern proves to be useful as it tells you what is the meaning of each field that is being printed on the console or file.

The following example gives you an idea about the log message format:

2020-03-17 12:52:48,785 INFO [Adeptia Connect 3.2 Kernel Thread] system com.adeptia.indigo.event.QuartzEventFactory.activateAutoCleanupService(QuartzEventFactory.java:636)

- category="initializeEvent" groupId="administrators" message="DEFAULT.autoCleanup will run at: Sat May 23 03:00:00 UTC 2020" nodeName="10.0.0.72" userId="admin"

Logging configuration

Logging parameters are pre-configured in the application. However, if you want to update the configuration parameters, you can follow the steps below to navigate to the Asynchronous logging properties window and update the properties:

1. Click Configure > Developer Studio.
2. Click Proceed.
3. On the Connect Server home page, click Administer tab.
4. Go to Setup menu and select the Application Settings option.
5. Click Update System Properties.

6. Navigate to Systems > Asynchronous Logging.

   
   
   

   Setting the abpm.log4j.async.logging.enable property to false changes the logging to be in Synchronous mode. By default, this property is set to true. You can also update the rest of the listed properties based on your requirements.

Properties configuration

If required, you can configure the logger properties in server-configure.properties file. Follow the steps below to perform this action:

1. Go to …<ConnectServerInstallFolder>\AdeptiaServer\ServerKernel\etc location.
2. Open server-configure.properties file.

3. The following table contains the list of configurable properties:

   Property	Description	Possible value
   log4j.rootLogger	System and process flow logging level. For production server, it is recommended to use NOTICE log level.	ERROR, NOTICE, INFO, and DEBUG
   log4j.logger.Event	Events logging level. For production server, it is recommended to use NOTICE log level or leave it without any value. In case of no value, it will consider the logging level from the property log4j.rootLogger.	ERROR, NOTICE, INFO, and DEBUG. Or, you can leave it without any value.
   log4j.logger.runtime	Runtime logging level. For production server, it is recommended to use NOTICE log level or leave it without any value. In case of no value, it will consider the logging level from the property log4j.rootLogger.	ERROR, NOTICE, INFO, and DEBUG. Or, you can leave it without any value.
   log4j.logger.audit	Audit logging level. For production server, it is recommended to use NOTICE log level or leave it without any value. In case of no value, it will consider the logging level from the property log4j.rootLogger.	ERROR, NOTICE, INFO, and DEBUG. Or, you can leave it without any value.
   log4j.logger.system	System logging level. For production server, it is recommended to use NOTICE log level or leave it without any value. In case of no value, it will consider the logging level from the property log4j.rootLogger.	ERROR, NOTICE, INFO, and DEBUG. Or, you can leave it without any value.
   abpm.log4j.async.logging.enable	Enable/disable asynchronous logging in the application.	true or false
   log4j2.asyncLoggerExceptionHandler	Name of a class that will be notified when an exception occurs while logging the messages.	Name of the class. For example, com.adeptia.indigo.logging. AsyncLoggerExceptionHandler.
   log4j2.asyncLoggerRingBufferSize	Size (number of slots) in the RingBuffer used by the asynchronous logging subsystem.	Minimum size = 128. Maximum size = Based on your requirements.
   log4j2.asyncQueueFullPolicy	To drop events whose level is equal or less than the threshold level (INFO by default) when the queue is full.	Discard
   log4j2.discardThreshold	To determine which events to be dropped when the queue becomes full. This works only when 'log4j2.asyncQueueFullPolicy' property is set.	ERROR, INFO, and DEBUG