Reading the varnishlogΒΆ

What do the lines in varnishlog output mean?

See man vsl(7) for full documentation of the format and contents of Varnish log tags (or see the online link, in this case for current trunk, or for your Varnish version).

How do I filter varnishlog output to make it more manageable?

man vsl-query(7) shows you how to use VSL queries to pick out log transactions with contents you specify. See also man varnishlog(1) for command-line options that restrict the output for each transaction. Some useful ones are:

  • -i: only show log lines with certain tags
  • -I: only show lines matching a list of tags and a regular expression
  • -x: don’t show lines with certain tags
  • -X: don’t show lines matching a list of tags and a regular expression

Multiple options are allowed on the command line for each of these.