Details of Tachyon Server and Agent log files.

Server Logs

1E Tachyon Coordinator service

1E Tachyon Switch Host service

Background web application (Background Channel)
Consumer web application (Consumer API)
Core & CoreInternal web applications
Explorer (Explorer and Admin porta)n/a

The default location for all Tachyon Server logs is the folder %ALLUSERSPROFILE%\1E\Tachyon\

Please refer to Services and NTFS Security if changing the location of log files.

In this version of Tachyon Server, the installer does not support the LOGPATH property and the logs folder is not configurable during installation.

Each component has a configuration file in the Tachyon Server installation folder structure, which contains log configuration details. Defaults are:

  • Filepath %ALLUSERSPROFILE%\1E\Tachyon\
  • Filename as shown in the table above.
  • Maximum size 10MB (2MB for Switch logs).
  • 2 rollover files numbered 1 to 2 with the rollover number included as n.log (5 rollover files for Switch logs).
  • Date and timestamps are UTC to help troubleshooters synchronise logs on systems in different timezones.

Switch logs have the following names:

  • The first Switch installed will typically have a log filename Tachyon.Switch_A.log
  • Other Switches on the same server will have different letters appended. The letter is derived from the ID in the SwitchConfiguration table, where the letter is modulo 26 of the ID minus 1, for example ID=2 is A and ID=6 is E.
  • The log filename will be unique on a server, but there may be the same named log on a different server.
  • A Switch will continue to use the same log, unless the SwitchConfiguration table is modified so that a different ID is used.
  • If you see a Tachyon.Switch.log without a letter appended, this is a special case where a Switch cannot find its correct configuration, and has fallen back to using the template * row which has ID=1. In which case you will need to troubleshoot how that happened.
  • Rollover logs have numbers appended, for example Tachyon.Switch_A.1.log, up to a default maximum of 5.

Tachyon server components use the log4net RollingFileAppender class. Details can be found in

On this page:

Logging Levels

The table below describes the logging levels which are configurable for server components.


Only outputs errors. An error is a serious problem, typically requiring operator intervention of some sort to restore full functionality.


Outputs errors and warnings. A warning indicates a potential problem, where the system can nonetheless function without intervention.


Outputs general information in addition to the errors and warnings. This is the default.


Outputs debugging information in addition to all the previous levels.

TraceOutputs the maximum information available. Used only in exceptional circumstances as it will generate huge amounts of logging output.
Logging levels should only be changed from info only if requested by 1E Support and reset to info after investigation is complete.

The method of configuring logging levels for the Tachyon Switch changed in v3.3 to using the above text values, but retains -log=0 as the default to mean the same as -log=info.

Tachyon Agent Logs

The logpath can be set using an installation property and changed post-installation using a configuration property, as decribed in the Tachyon Agent installer and configuration properties (Logpath).

The following are default logpaths:


Mac OSX:

Other non-Windows platforms:

By default, Windows resolves %ALLUSERSPROFILE% as follows.

For Windows 7 and later - C:\ProgramData\

Prior to Windows 7 - C:\Documents and Settings\All Users\Application Data\

The following are not configurable in this version:

  • Maximum size of 5MB
  • 5 rollover files numbered 1 (newest) to 5 (oldest) with the rollover number included as n.log

Console Logs

The Tachyon Explorer and Admin portal uses a web browser and does not have any client logs.