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Logging TraceListener Improved

I made a few improvements to the Logging TraceListener:

  • Files can now be aged by date as well as size
  • Filename is now completely templated using a single FileNameTemplate property, which supports standard String.Format codes for file number and date
  • Added seperate properties to specify units of scale for age and size (kb, month, gb, week)
  • Default limit changed to 1mb maximum size, no age limit, no file count limit

Here's how the new options look when set it up via the .config file:

<!-- this enables IIS-style logging of console output -->
<trace autoflush="true" indentsize="4">
<add name="CyclicLog"
initializeData="fileCountThreshold=10, fileSizeThreshold=512,
fileSizeUnit=kilobytes, fileAgeThreshold=1, fileAgeUnit=months,
fileNameTemplate='console-{1:MMM-yy}-{0:0000}.log'" />

And here's how it looks when created manually:

_HtmlLogger = New CyclicLogTraceListener
With _HtmlLogger
.TimeStampFormat = ""
.FileNameTemplate = "html-{1:MMM-yy}-{0:0000}.log"
.FileAgeThreshold = 1
.FileAgeUnit = CyclicLogTraceListener.AgeUnit.Months
.FileCountThreshold = 3
End With

I did this to get a seperate, private log file for the large amounts of HTML I wanted to trace. Including them with the regular console output is way too noisy. I combined age, number, and size limits, so I end up with something like this:

html-Feb-05-0000.log        (1mb)
html-Feb-05-0001.log        (1mb)
html-Mar-05-0000.log        (1mb)
console-Feb-05-0000.log   (512kb)
console-Mar-05-0000.log   (512kb)

With the configuration specified above, no more than 3 logs will ever exist, and no more than 3 per month, and never more than 512kb or 1mb in size.

Written by Jeff Atwood

Indoor enthusiast. Co-founder of Stack Overflow and Discourse. Disclaimer: I have no idea what I'm talking about. Find me here: