Apache Hop’s logging architecture is mostly readable from our source code. In the following sections, we provide a general layout and concepts to get familiar with.


The HopLogStore.getInstance() is where Channels are able to store and append their logs. HopLogStore is initialized when you run HopEnvironment.init()


Every runtime object (IPipelineEngine, IWorkflowEngine, etc.) in Apache Hop has a log channel ID with which you can examine the HopLogStore for what was logged for an ID.

Logging Registry

The logging hierarchy is in LoggingRegistry.getInstance()

Log text

To get logging text you can do something like: HopLogStore.getInstance().getAppender().getBuffer(pipeline.getLogChannelId(), true);