Valid HTTP Response Code Ranges:
You can use this section to specify the HTTP response codes that you will
regard as proof that the Remote Host is available. For example, if
a 200 OK HTTP response is received for the poll request, the Remote Host
can be considered available.
To specify a range of HTTP status codes, click the Add
button and enter the Start and End of
the range of HTTP response codes in the fields provided. An exact
response code can be specified by entering the response code in both
fields, e.g. "200".
HTTP Request for Polling:
The fields in this section allow you to configure the type and URI of the
HTTP request to use to poll the Remote Host with. The default option is
to use the Options HTTP command with a URI of "*",
which is typically used to retrieve status information about the HTTP
server.
If you wish to use an alternative HTTP request to poll the Remote Host,
select an HTTP request method from the Method dropdown
and then specify the URI to use in the URI field.
Remote Host Polling:
The settings in this section determine when and how the HTTP Watchdog
polls the Remote Host. The Poll Frequency determines
how often the Watchdog is to send the polling request to the Remote Host.
By default, the Watchdog uses "real" HTTP requests to the Remote Host to
determine its availability. In other words, if the Enterprise Gateway is
sending a batch of requests to the Remote Host it will use the response
codes from these requests to decide whether or not the Remote Host is
up. Therefore, the Watchdog effectively "polls" the Remote Host by
sending real HTTP requests to it.
If you want to configure the Watchdog to send poll requests during periods
when it is not sending requests to and receiving responses from the Remote
Host, you should select the Poll if up checkbox. In
this case the Watchdog will use "real" HTTP requests to poll the
Remote Host as long as it is sending them, but will start sending
"test" poll requests when it is not sending HTTP requests to the Remote
Host in order to test its availability.
It is important to note that once a Remote Host is deemed to be down (i.e.
an "invalid" HTTP response code was received) the Watchdog will continue
to poll it at the configured Poll Frequency until it
comes back up again (i.e. until a "valid" HTTP response code is received).
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