After completing this lesson, you’ll be able to:
The FME log file is your best friend for debugging. It tells you how long a translation took, where the time went, and how well FME used the available system resources.
The first thing to notice is that each line of the log is (in most cases) a separate message, for example:
Creating writer for format: Esri Shapefile
However, sometimes the message spans several lines, such as:
Feature Caching is ON
The workspace may run slower because features are being recorded on all output ports.
Stop At Breakpoints is ON
The workspace may run slower, even when no breakpoints are present. In particular, Bulk Mode is not supported with this enabled.There are several options to adjust what appears in the log file. To access these, select Tools > FME Options > Translation:
The critical setting is Log Timestamp Information. This option turns on many optional fields in the log messages. These are:
For example:
2019-04-01 12:13:55| 0.8| 0.0|INFORM|Closing native MapInfo reader
You can use these timestamps to identify slow sections of your workspace.
The log file always contains timestamps, regardless of this setting.
A common requirement is to filter log messages so only messages of a specific type are displayed. For example, turning off INFORM and STAT messages can make spotting ERRORs and WARNs easier.
There are two ways to achieve this. Firstly, you can filter log messages under options under Tools > FME Options > Translation:
These options turn each message type on (or off) for all subsequent translation logs. If a message type is unchecked here, it will not appear in the log.
The second method of filtering is a set of tools in the log window itself:
These buttons can toggle messages on and off in the log window only. They are easier to use and more flexible than FME Options for filtering.
The Log Debug option (under FME Options) allows you to turn on debug messages in the log. These are extra log messages that do not appear by default. Debug logging records additional translation information to the job log. “Debug mode” is best used when an error has already occurred and you seek further information. For example, in the event of a web and database failure, “debug mode” will often record more detailed information about the request, response, and transaction to the job log.
You should turn this off when you are not using it, as it can dramaticly increase the size of your log files. This setting can become an issue on FME Flow in particular, where users might be running a workspace very often
⭐ New for FME 2024.1: we've simplified log debug mode by removing these multiple checkboxes and providing only a single Log Debug checkbox, which now appears at the top of the Log Settings section:
If you don't want to see certain message types, use the filter buttons available at the top of the Translation Log window.
Debug messages can help during debugging but are less useful in general FME use. Many messages (labeled "BADNEWS") are alarming “errors” that FME has trapped and kept to itself (like an end-of-file message). For this reason, you should not turn this option on permanently.
Also, note that the Log Debug setting persists in the workspace. If you turn that setting on and pass the workspace to another user, it retains the setting and shows debug messages when other users run it!
If the log window text is too small or not stylish enough, use Tools > FME Options > Appearance > Log Font to change the font size and style.
