Pagination#

Pagination provides the ability to limit the size of the returned data in the response body as well as retrieve a specified subset of a large data set. Pagination has two key concepts: limit and marker.

  • Limit is the restriction on the maximum number of items for that type that can be returned.

  • Marker is the ID of the last item in the previous list returned.

    The ID is the UUID in the case of instances, the name in the case of databases, and “name@host” for users. For example, a query could request the next 10 instances after the instance “1234” as follows:

    ?limit=10&marker=1234

    Items are displayed sorted by ID.

If the content returned by a call is paginated, the response includes a structured link much like an instance item’s links, with the basic structure {“href”: “<url>”, “rel”: “next”}. Any response that is truncated by pagination will have a next link, which points to the next item in the collection. If there are no more items, no next link is returned.

Pagination applies only to the calls listed in the following table:

Verb

URI

Description

GET

/instances/

Lists the status and information for all database instances.

GET

/instances/{instanceId}/databases

Lists databases for the specified instance.

GET

/instances/{instanceId}/users

Lists the users in the specified database instance.

Cloud Databases has separate paging limits for instances (20), databases (100), users (20), and backups (20), with the default limit for each set to the paging limit. If a request supplies no limit or one that exceeds the configured default limit, the default is used instead.

See the example of paged List Instances calls that follow.

Example: List instances paged request: JSON

GET /v1.0/1234/instances?limit=2 HTTP/1.1
User-Agent: python-troveclient
Host: ord.databases.api.rackspacecloud.com
X-Auth-Token: 87c6033c-9ff6-405f-943e-2deb73f278b7
Accept: application/json
Content-Type: application/json

Notice that the paged request example above sets the limit to 2 (?limit=2), so the responses that follow each show 2 instances and return a marker set to the UUID of the last item in the returned list (?marker=d4603f69-ec7e-4e9b-803f-600b9205576f). Also a link is provided to retrieve the next 2 results (limit=2) in the link element identified by the attribute "rel":"next":

Example: List instances paged response: JSON

HTTP/1.1 200 OK
Content-Type: application/json
Via: 1.1 Repose (Repose/2.6.7)
Content-Length: 1237
Date: Thu, 13 Feb 2014 21:47:16 GMT
Server: Jetty(8.0.y.z-SNAPSHOT)

{
    "instances": [
        {
            "datastore": {
                "type": "mysql"
            },
            "flavor": {
                "id": "1",
                "links": [
                    {
                        "href": "https://ord.databases.api.rackspacecloud.com/v1.0/1234/flavors/1",
                        "rel": "self"
                    },
                    {
                        "href": "https://ord.databases.api.rackspacecloud.com/flavors/1",
                        "rel": "bookmark"
                    }
                ]
            },
            "id": "4bf79039-dc7f-49c3-a285-03e1ad1e6cbf",
            "links": [
                {
                    "href": "https://ord.databases.api.rackspacecloud.com/v1.0/1234/instances/4bf79039-dc7f-49c3-a285-03e1ad1e6cbf",
                    "rel": "self"
                },
                {
                    "href": "https://ord.databases.api.rackspacecloud.com/instances/4bf79039-dc7f-49c3-a285-03e1ad1e6cbf",
                    "rel": "bookmark"
                }
            ],
            "name": "The Third Instance",
            "status": "ACTIVE",
            "volume": {
                "size": 2
            }
        },
        {
            "datastore": {
                "type": "mysql"
            },
            "flavor": {
                "id": "1",
                "links": [
                    {
                        "href": "https://ord.databases.api.rackspacecloud.com/v1.0/1234/flavors/1",
                        "rel": "self"
                    },
                    {
                        "href": "https://ord.databases.api.rackspacecloud.com/flavors/1",
                        "rel": "bookmark"
                    }
                ]
            },
            "id": "d4603f69-ec7e-4e9b-803f-600b9205576f",
            "links": [
                {
                    "href": "https://ord.databases.api.rackspacecloud.com/v1.0/1234/instances/d4603f69-ec7e-4e9b-803f-600b9205576f",
                    "rel": "self"
                },
                {
                    "href": "https://ord.databases.api.rackspacecloud.com/instances/d4603f69-ec7e-4e9b-803f-600b9205576f",
                    "rel": "bookmark"
                }
            ],
            "name": "json_rack_instance",
            "status": "ACTIVE",
            "volume": {
                "size": 2
            }
        }
    ],
    "links": [
        {
            "href": "https://ord.databases.api.rackspacecloud.com/v1.0/1234/instances?marker=d4603f69-ec7e-4e9b-803f-600b9205576f&limit=2",
            "rel": "next"
        }
    ]
}