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Appendix B
Traffic Manager Configuration Options
The Logging page
The following table describes the configuration options on the Logging page.
Background timeout
Specifies how long DNS entries can remain in the database before they are
flagged as entries to refresh in the background. These entries are still fresh, so
they can be refreshed after they are served, rather than before.
Example:
The foreground refresh timeout interval is 24 hours and the
background timeout is 12 hours. A client requests an object from
my.com
and 16
hours later a client makes a second request for an object from
my.com.
The DNS
entry for
my.com
has not been refreshed in the foreground because the entry is
not yet 24 hours old. But since the background timeout has expired, the Traffic
Server will first serve the client’s request, then refresh the entry in the
background.
Invalid host timeout
Specifies how long the proxy software should remember that a hostname is
invalid. This is often called negative DNS caching.
For example, if a client specifies an invalid hostname, the Traffic Server informs
the client that it could not resolve the hostname and the Traffic Server gets
another request for the same hostname. If the Traffic Server still remembers the
bad hostname, it will not try to look it up again, but will simply send another
invalid host name
message to the client.
Re-DNS on Reload
Tells the Traffic Server to re-resolve hostnames whenever clients reload pages.
DNS Configuration
Resolve attempt
timeout
Specifies how long the Traffic Server must wait for the DNS server to respond
with an IP address, even if the client request has been cancelled.
NOTE:
If the client abandons the request before this timeout expires, the Traffic
Server can still obtain the host’s IP address in order to cache it. The next time a
client makes the same request, the address will be in the cache.
To provide DNS services, the Traffic Server uses a list of DNS servers that it
obtains from the DNS table in your
resolv.conf
file. The Traffic Server always
tries to connect to the first DNS server on the list; if it cannot make or maintain
the connection, it tries the next server on the list.
Number of retries
Specifies how many times the Traffic Server should allow a look-up to fail before
it abandons the look-up and sends an
invalid host name
message to the user.
Options
Description
Event Logging
Logging Enabled
Enables/disables the logging feature so that transactions are recorded into event
logs and error logs.
Log Transactions Only
Configures Traffic Server to log transactions into your selected event log files
only. Errors are not recorded in the error log files.
Log Errors Only
Configures Traffic Server to log errors in the error log files only. Transactions are
not logged in event log files.
Logging Disabled
Disables the logging feature.
Log Management
Log directory
Specifies the path of the directory in which to store event logs. The path of this
directory must be the same on every node in the Traffic Server cluster.
Option
Description