Streaming Media Supplement sa2150 and sa2250

109
Chapter 10 Logging and Monitoring
About the styp field
The styp logging field first of all indicates whether a stream was live or on-demand content. On-demand content
is potentially cacheable–but since not all on-demand content actually ends up being cached, styp also provides
information about the circumstances under which the stream was or was not cached.
RealNetworks and the styp field
The styp logging field is supported for WMT and QuickTime. The styp logging field is not supported for
RealNetworks; there is no need for a field to distinguish live from on-demand RealNetworks content, because
live RealNetworks streams are handled by the RealProxy component of Media-IXT, so only on-demand,
cacheable streams are logged by Media-IXT. (Use of selective caching in hierarchical deployments may
produce some exceptions to this rule.)
For RealNetworks content, the value of the styp field appears as -/-.
Values of the styp field
There are two values in styp:
STREAMTYPE is either demand or live, meaning that a stream was on-demand or live content, respectively.
CACHETYPE can be any of nine values, shown and explained below:
Transaction logging fields: table and illustrated examples
The table and illustrations that follow explain Media-IXT’s logging fields.
The table lists all the fields in complete-mixt.log in alphabetical order. The two illustrations that follow
the table show sample complete-mixt.log log file and summary-mixt.log log file entries broken
down field by field. In the log entries the fields do not appear in anything like alphabetical order, so it may be
helpful to refer to the illustrations when you are learning to decipher log entries.
Some fields are unique to Media-IXT logs while others may appear in both Traffic Server http transaction
logs and in Media-IXT logs. The HP Cache Server Appliance Administrator Guide shows that there are also
numerous fields used in Traffic Server http logs that Media-IXT does not use. This is because some fields
make sense for http transactions but not for streaming transactions, and vice versa.
Where Squid equivalents to Media-IXT logging fields are available, they are listed in the table.
Information about several logging fields that is too lengthy to fit in the table appears earlier in this chapter.
In the illustrations, the values of fields with a large number of digits are abbreviated.
Value Meaning
cached written to and read from cache normally
passthrough generic passthrough; no caching
passthrough-filter cache.config rules dictate that this stream should not be
cached, so it is proxied in passthrough mode
passthrough-authenticated the stream is proxied in passthrough mode because its content is
authenticated
split this is a live split stream
denied-filter denied due to filter.config rules
denied-origin-auth-failure because of failure of origin authentication challenge
denied-proxy-auth-failure because of failure of proxy authentication challenge
non-existent file does not exist on origin