Efficient Polling with the Changes-Since Parameter#
You can poll for the status of certain operations by issuing a GET
request on various elements. Rather than re-downloading and re-parsing
the full status at each polling interval, you can use the
changes-since parameter to check for changes since a previous
changes-since time is specified as an ISO
The operations that use the
changes-since filter are:
- GET /servers
- GET /servers/detail
- GET /images
- GET /images/detail
The format for the timestamp is:
Optionally, to return the time zone as an offset from UTC, append the following:
If you omit the time zone (2011-01-24T17:08), the UTC time zone is assumed.
If data has changed, only the items changed since the specified time are returned in the response.
If date has not changed since the
changes-since time, an empty
list is returned.
For example, issue a GET request against the following endpoint to list all servers that have changed since Mon, 24 Jan 2011 17:08:00 UTC:
To enable you to keep track of changes, the
also displays images and servers that have been deleted provided that
changes-since filter specifies a date in the last 30 days.
Items deleted more than 30 days ago might be returned, but it is not