HP P4535A - Web Cache Server Appliance, Руководство администратора, Страница: 147 / 251

135
Appendix B Traffic Manager Configuration Options
The Cache page
The following table describes the configuration options on the Cache page.
Option Description
Cache Activation
Enable HTTP caching Configures the Traffic Server to cache objects retrieved via HTTP.
Enable FTP caching Configures the Traffic Server to cache FTP objects retrieved via HTTP.
Enable NNTP caching Configures the Traffic Server to cache objects retrieved via NNTP
Ignore user requests to
bypass cache If clients stipulate that their requests are not to be served from the cache, ignore
the stipulation (ignore client Cache Control:
no-cache
headers).
Storage
Maximum HTTP/FTP
object size in bytes Specifies the maximum size of HTTP or FTP objects to be cached.
CAUTION: If you enter
0
(zero), there is no limit on the maximum HTTP or
FTP object size.
Maximum number of
alternate versions
(HTTP) Specifies the maximum number of HTTP alternates that Traffic Server can
cache.
CAUTION:
If you enter
0
(zero), there is no limit on the number of alternates
cached. If a popular URL has thousands of alternates, you might observe
increased cache hit latencies (transaction times) as Traffic Server searches over
the thousands of alternates for each request. In particular, some URLs can have
large numbers of alternates due to cookies. If Traffic Server is set to vary on
cookies, you might encounter this problem.
View cache storage
configuration Click this link to see a list of the files or hard disk partitions allotted to cache
storage and their sizes.
NOTE: Raw partitions may not have an associated size.
Freshness
Verify freshness by
checking Configures the Traffic Server to ask the origin server to verify the freshness of
objects before serving them. Configures the Traffic Server to ask for
verification:
•
When the object has expired
•
When the object has expired or if the object has no expiration date
•
Always
•
Never
Minimum freshness
information for a
document to be
cacheable Specifies the minimum freshness information required to consider a document
cacheable:
•
An explicit lifetime
•
A last-modified time
•
Nothing
If an object has no
expiration date Some origin servers do not stamp the objects they serve with an expiration date,
but you can control how long these objects remain in the cache by specifying:
•
The minimum time they can remain in the cache (from 15 minutes to two
weeks).
•
The maximum time they can remain in the cache (from 15 minutes to two
weeks).
FTP cached objects
expire FTP objects carry no time stamp or date information and stay in the Traffic
Server cache pending removal on a schedule you specify (from 15 minutes to
two weeks).