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Viewing your log events

When using FusionReactor Cloud you will have access to the Logging feature area. Here we will cover how to best use this feature to explore and gain insights into your log content.

Below is a diagram explaining the different features available while exploring your log events.

We will explain how to operate key features in subsequent sections.

Labels Explorer

The label explorer allows you to quickly generate a LogQL query from your available labels.

Using logs shipped from FusionReactor , you will by default be able to filter by job, instance, filename and app_name. The label explorer will also work with any custom labels you ship logs to FusionReactor Cloud using alternate methods to the FusionReactor agent.

Log labels and fields

Clicking on a log entry will display the labels and fields it has associated with it.

Graph cardinality (statistics)

You can view the statistics for any label or field, this will give you a count and breakdown of the value variations.

It’s important to note these cardinality stats only represent the data you have loaded in your browser (current maximum is 200 log entries).

An example of this would be to see a breakdown of which threads requests are running on.

Graph metrics

For any numerical label or field, you can render a time series graph for the field values.

Here is an example of graphing the freed memory of all jobs within my selected time period.

Recent / saved / example queries

Under the help menu, we have a selection of example queries you can run including broad text search for errors, showing the ingest rate of logs and finding the top 10 IP addresses hitting your application (this query requires the request log from the FusionReactor agent).

Any queries you have recently ran will be available under the recent / saved queries, so you can find interesting queries you ran in the past. These queries can be filtered for a specific query to require.

If you have an interesting query you need to run again in the future, you can save it by clicking on the save query button. Then later you can find the query under recent / saved queries.

Log Context

When using broad text search for logs or if you are viewing multiple log files simultaneously, you can use the show context feature to show logs surrounding that particular log line. You do this by clicking the blue show context link on the right of the log entry.

This will give you the context of that particular log line so you can investigate an issue further. This means that it will show you logs that match all the labels present on the log entry of interest, in this example it shows log entries around my chosen log entry with the following labels, job=store-1, instance=f39866b4289f, filename=stdout, app_name=MyApplication

In this particular case I am showing the context around my log entry that contained the text “Exception” which allows me to see the full stack trace.


We want logs to be as readable as possible, to enable this we have added a display preferences panel where you can change the font family and font size as well as other display preferences such as which log labels are visible and the ability to truncate log content to make it easier to scan down your log content.

Historic vs Live logs

To view historical logs you can manipulate the time picker on the top right of the cloud UI. Logs will be loaded in chunks, so you can scroll up to view earlier log entries for your selected time period.

If you wish to view the logs as they are ingested, you can do this by clicking play in the bottom right corner. This will poll for new log entries at a pre configured interval.