If this file exists at the beginning of ecFlow execution, it is appended to. Otherwise, it is created. The location and name of the log file can be configured using the environment variable ECF_LOG, which can be set before the ecFlow server starts.
Information message generated by ecflow_client commands in a job or user action, normal operation.
Information message generated by task or ECF, normal operation. These are mostly messages generated when nodes go through status changes.
An error message, abnormal operation the action could not be done. Some errors are ignored on the client-side, for example trying to send a label or an event that does not exist in ecFlow server is an error on the server side but not on the client-side.
Warning message, not an error but corrective action was taken. For example, using an old version of the client may cause a warning message to be printed.
Debugging message, by default these are not visible they must be turned on by a privileged user.
There could be a keyboard echo in the log file if ecFlow is running interactively; these lines should be ignored by programs processing the log file.
The log file contains all the actions of the ecFlow server and shows information such as the halt, shutdown, etc. It is a pure text file and can easily be processed by other programs. For example, ecflow_ui uses this file to show the timeline window.
The syntax of the log file is fairly simple. For each action in ecFlow, a line is output.
The format is as follows:
XXX:[HH:MM:SS D.M.YYYY] command:fullname [+additional information]
Where XXX is one of the symbols in the above table. The timestamp inside  is the system time, not the suite time, which may differ.
Note: that user commands often generate both MSG and LOG level messages. MSG is the command executed and LOG is the effect it had on the node or nodes.
Note: The log file is not removed so it needs to be managed. We tend to compress and archive our log files each day using an ecFlow controlled script.
The log file grows over time and should be managed. You can manipulate the log files using the client command --log. Type ecflow_client --help log for details. This allows you to get, clear, flush, or create a new log file.