Logger

The Logger is a global server configuration property which allows the input and output of selected context function calls, as well as selected context variable read/write operations, to be logged or otherwise processed.

When the logger is enabled, all function calls and variable operations will be passed to the special logger expression. The expression is used to filter and process particular functions or variable operations.

Session Logger Configuration

This group contains options which govern how the logger operates.

Enabled

Indicates if logging is enabled.

Property name: enabled

Property type: Boolean

Expression

Expression to filter events for logging and indicates how the filtered data should be processed.

Property name: expression

Property type: String

Normal Concurrent Tasks

The default number of threads to be maintained for processing logging tasks.

Property name: normalLoggerConcurrentWorkers

Property type: Integer

Maximum Concurrent Tasks

The maximum number of threads which can be activated to process tasks as queue length grows.

Property name: maximumLoggerConcurrentWorkers

Property type: Integer

Maximum Unprocessed Tasks Queue Length

Maximum number of tasks which can be queued. When the task queue has reached this maximum, additional tasks will be discarded.

Property name: maximumLoggerQueueLength

Property type: Integer

Resolution Environment

Session Logger Expression Resolution Environment:


Default Context

The context of the variable or function which is being logged. Note that this is available in the environment variable context.

Default Data Table

Data Table containing event-specific data for triggering event.

Default Row

0

Environment Variables

Variable Name

Value Type

Description

address

String

IP address of the client.

context

String

Full path to the operation's context.

duration

Long

Execution time of the operation.

entityName

String

Name of the function or variable.

input

String

Input parameters (function input or value for variable set operation)/

login

String

Login name of the user executing the operation

operationType

String

Type of operation, one of the following:

  • CALL_FUNCTION

  • GET_VARIABLE

  • SET_VARIABLE

output

String

Output parameters (function output or retrieved value from get variable operation)

sessionId

Integer

Id of the current session

username

String

Username

Example Session Logger Expression

All function and variable operations will trigger the expression. Take care to craft an expression which processes the precise operations of interest and logs the desired data without overtaxing system resources.

The following example first filters for entities named criticalContext. In this case it will filter for calls to functions named criticalContext and get or set operations on variables named criticalContext.

If this criteria is met, the function log is called in the example device sampleCollector and logs the following information concatenated into a string:

now() - The current timestamp.

{context} - The default context.

{operationType} - Indicates if the logged operation was a function call or getting or setting a variable.

{entityName} - The name of the variable or function called. In this example it will always be criticalContext.

{duration} - The amount of time spent executing the function call or get/set variable operation.

{entityName} == "criticalContext" ? 
callFunction("users.admin.devices.sampleCollector", "log", now() + "', '" + {context} + "', '" + {operationType} + "', '" + {entityName} + "', " + {duration} + ")", true) 
:

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