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Scientific Volume Imaging B.V.

Scientific Volume Imaging

Deconvolution - Visualization - Analysis


Huygens Execution Log File

The Huygens Software reports some of its internal operations in a file that is saved on a storage disk: the Execution Log. Additionally, some supplementary logs are created. This information is very welcome in many support procedures because it helps in spotting the cause of an internal problem.

Location of the log files

This section describes the location of the log files for Huygens 25.10.1 and later. For older Huygens versions, please see below.

Usually, the easiest way to find the directory where execution logs are saved is by using Huygens: you can open the log location by clicking on the "Help" menu in the top of the main window, and then selecting "Locate logs", as shown on the right.

Then, in the opened directory, select the directory of the day Huygens was started (e.g. 2025-11-01), and then the folder with the time you started Huygens (e.g. StartTime_12h-22m-59s). The times shown here use a 24 hour clock, so when you started Huygens at 3PM the folder name will be StartTime_15h-00m-00s. Please send all contents of this folder to SVI via email or, if the files are too large via for example our Upload page.

In case you are not able to find the directory via Huygens, like when using Huygens Core or when Huygens does not start at all, the log files will be located here:

  • For Windows:
    Copy to clipboard
    C:\Users\<user_name>\SVI\ExecLog
  • For Linux and MacOS:
    Copy to clipboard
    /home/<user_name>/SVI/ExecLog/

LocateLogs

Location in older Huygens versions (before 25.10.1)

In older Huygens versions the Log directory is not accessible via the software, and Log files are not bundled in one folder per session like in newer Huygens versions. Instead you can find the in one of the following locations:

  • For Windows:
    • Copy to clipboard
      C:\Users\<user_name>\SVI\ExecLog
    • Copy to clipboard
      C:\Users\<user_name>\SVI\ExecLog\Old\<yyyy-mm-dd>
  • For Linux and MacOS:
    • Copy to clipboard
      /home/<user_name>/SVI/ExecLog/
    • Copy to clipboard
      /home/<user_name>/SVI/ExecLog/Old/<yyyy-mm-dd>

The main log file is named session_<ID>_date_<YYYY-MM-DD>_<HHMM>_huygens.log and will look like session_1228810799_date_20014-12-09_0919_huygens.log.

The log files belonging to children processes of the Batch Processor (each deconvolution task) are names as follows: session_1228810799_date_2014-12-09_0920_huygens_subTask_0.log

This means that parent and children share the same session ID, but the date of the creation of the file may differ because children log files are created later.

There may also be task-<DDMMYY>-<HH>_<MM>_<SS>.log, task-0-<DDMMYY>-<HH>_<MM>_<SS>.log ... which contain the actual command for the different tasks in the Batch Processor.

The important files have extension .log, not .txt. The .txt files are for you to get some feedback of the problem without many technical details.

Sending your files

Since log files can be quite large in some situations, you can upload them via for example our Upload page, instead of sending them via email.

Organization of the log files

Whenever you restart Huygens, log files older than a set time are automatically deleted. You can configure this time in the Program Preferences, the default value is 30 days.

Console output

When everything fails at a very early stage and the execution log isn't even created, the text messages that the program or the operating systems sends to the console are very important.

In Windows, retrieving console output from non-console applications is unfortunately not possible. Still, there is a console version of Huygens Core in your SVI/bin program subdirectory that you can run from a console and that will return some interesting output. Press (Windows+R) in your keyboard, type cmd and press Enter to open a console, go to the Huygens Application Directory with cd "\Program Files\SVI\bin" or cd "\Program Files (x86)\SVI\bin" and execute hucore.exe. Right-click on the screen with the mouse to open a popup menu that will let you mark and copy the text (Ctrl-C won't do!!!). You can paste this in an email to SVI.

In Linux, you may need to run the program from a terminal so that the output is shown. Open a terminal (shell) and execute essential, for example. If the whole path is needed you can use /usr/local/svi/bin/essential.

In Mac, the Console utility lets you retrieve that output even when the application was not executed from a terminal. You can find this program in /Applications/Utilites/Console.app. The lines from the Huygens Software are tagged with nl.svi.essential or the name of other product in the suite. You can select several lines, copy them, and paste them in an email to SVI.

Log file options

Through the program preferences (Edit -> Preferences in the main window) and by using some command line options when launching the program, you can configure the behavior of the execution log file.

In the Program Preferences:

  • Number of days to keep old log files.
  • Performance of the log writer: flush each entry immediately to the file on disk, or accumulate it in a buffer in memory to reduce the number of disk accesses. The latter option may improve performance but in case of a crash the information in the buffer may not had time to reach the disk and the relevant information may be lost.

Command line options:

  • Do not write an execution log at all: -noExecLog (useful in programming scripts for Huygens Core).
  • Force a flush of the log file after each entry from a very early stage of the initialization of the program (intended for critical crashes, to make sure that every entry is written before a crash happens): -flushLog