User manual

Chapter 3
20
cache hit latency vs. average cache miss latency as a function
of time of day.
• Usage Report. This report lists the names of client machines
and server machines that have retrieved (or served, in the
case of servers) more than a specified number of documents
or more than a specified number of total bytes of content.
Four thresholds are configurable: bytes per client,
documents per client, bytes per server, and documents per
server. Entering 0 for these fields will cause the report to list
all clients or servers (or both).
Cache Logs
The CacheRaQ’s caching software logs date to two files in its
normal course of operation — “access.log” and “cache.log.”
• Access.log contains one line per request served. Among
other things, each line lists the URL of the requested
document, the client’s IP address, the size of the document,
and the time of the request. Access.log files can grow quite
large (up to approximately one hundred megabytes per day).
The amount of disk storage devoted to access.log files can be
set in the Cache Setings page, as described on page 13.
• Cache.log contains informational messages describing the
state of the cache software. Cache.log also lists error
messages that arise during normal operation. For example, a
message is logged whenever the caching software fails to
connect to a remote HTTP server.
Software on the CacheRaQ rotates access.log and cache.log files
once per day. Log files are saved until they exceed the disk space
allocation for log files. At this point, old log files are deleted until
disk space consumption is within the specified limit.
The Cache Logs page is divided into two sub-pages — one for
viewing the current day’s log files and one for downloading
previous days’ log files.
View Log Files. This page lets you select a log file (access.log or
cache.log) and enter a number of lines (N). It then displays the
most recent N lines of the selected log file. This is useful for
diagnosing any immediate problems (by viewing cache.log) and
for examining current client activity (by viewing access.log).