Logging

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1 Introduction

Below we describe what the various log levels of the runtime will show as output. During development, these log levels can be set in the console (advanced -> set log levels), when deployed on a server, please refer to the Deployment pages.

2 Log Levels

2.1 Critical

Critical is reserved for rare cases where the application may not be able to function reliably anymore. This should normally not occur. If it does, you should immediately take action. The 3.0 cloud treats these messages as alerts and will notify you on the cloud dashboard.

2.2 Error

Error is used to log all unhandled exceptions. These are unexpected events that should not occur, but are not critical. The application should be able to function normally afterwards.

2.3 Warning

Warning is often used for handled ‘exceptions’ or other important log events. For example, if your application requires a configuration setting but has a default in case the setting is missing, then the Warning level should be used to log the missing configuration setting.

2.4 Information

The Information level is typically used to output information that is useful to the running and management of your system. Information would also be the level used to log entry and exit points in key areas of your application. However, you may choose to add more entry and exit points at Debug level for more granularity during development and testing.

2.5 Debug

This should be used for debugging systems during development, but never in a production system. It can be used to easily pinpoint problems and the general flow of your application.

2.6 Trace

This is the most verbose logging level, and can be used if you want even more fine-grained logging than debug.

3 Log Nodes

This section provides some details on specific log nodes used by Mendix. It is recommended that if you write your own log messages you use your own log node names to avoid confusion with the Mendix log messages.

3.1 Default Mendix Log Nodes

The following log nodes are used by Mendix when writing log messages.

Log Node Description
ActionManager Log messages related to action scheduling (e.g. scheduled events) and action execution (e.g. running microflows).
Configuration Logging related to the configuration of the Mendix app that is read in at startup.
ConnectionBus General logging related to database startup, synchronization and connections management for Mendix.
ConnectionBus_Mapping Information relating to the translations of XPath Queries and OQL text queries to OQL Queries.
ConnectionBus_Queries Deprecated: This is a legacy node.
ConnectionBus_Retrieve All information related to the retrieval of data, such as: Incoming requests from the application, the executed statement. Also logs issues encountered during the processing of the received data.
ConnectionBus_Security Information regarding access rights needed to access the database.
ConnectionBus_Synchronize Deprecated: This is a legacy node.
ConnectionBus_Update All information related to the update of data in the database. Incoming storage requests, the executed statements and issues encountered during storage.
ConnectionBus_Validation Information related modification of the existing database, and database migration.
Connector
Core Logs messages from the core runtime. This can be startup of the runtime, version of the runtime, license being used and issues related to interpreting the model.
DataStorage_QueryHandling Logs messages related to the queries that are being executed.
DataStorage_QueryPlan Query execution plan information for installations (currently only supported for PostgreSQL databases).
DocumentExporter Logs messages related to the templating engine that generates documents.
FileDocumentSizesPopulateJob Logs messages for a background job that populates the file-size field in the database for documents that do not have that field filled (used during legacy migration).
I18NProcessor Logs messages related to translation of the app.
JSON JSON messages from the Mendix Client to the Runtime Server. See JSON, below, for more information
Jetty Logs messages from the internal Jetty webserver that handles HTTP requests between the runtime and the outside world.
LocalFileSystemStore Logs messages related to file handling if you are using local file system as your file store.
Logging Logs messages related to the logging framework used by Mendix.
M2EE Log messages from the administration interface with the runtime
MicroflowDebugger Log messages related to the status of the microflow debugger, e.g. connection status, incoming and outgoing requests, etc.
MicroflowEngine Log messages related to microflow execution, e.g. which microflow / microflow action is being executed and errors that occur during the execution.
ModelStore
Module Logs messages for modules that are loaded on-demand in the core runtime like the microflow-engine.
ObjectManagement Logs errors relating to attempts to make associations to non-existent object
OData Publish Log messages related to published OData services.
QueryParser Logs messages related to the parsing or interpretation of XPath and OQL queries.
REST Publish Log messages related to published REST services.
RequestStatistics
Services
StorageAzure Logs messages related to file handling if you are using Azure system as your file store.
StorageS3 Logs messages related to file handling if you are using Amazon S3 system as your file store.
StorageSwift
WebServices Traces SOAP call request and response contents.
WebUI

3.2 JSON

Has only one relevant level: Debug.

Setting this log level to debug will show you all the JSON requests and responses from the Mendix Client to the Runtime Server. This may degrade performance as this output is normally streamed. This can also be used to gain insight in what users are doing in a production environment. When using it here, make sure you have enough disk space available for your log files though.