Simple Load Balancing Pool

Simple Monitor / Failover (SF) provides probing, notification and failover of a web site's IPv4 address record to one other IPv4 address.

When using Simple Monitor / Failover, the defined probe sends HTTP(S) GET or POST requests from four locations towards the target system once every five minutes. The target system may be any host. Optionally, the request to the target system can include HTTP(S) Request data and/or the HTTP response data can be searched for specific content. If no search string is specified, the probe of the target is considered as successful if any non-error HTTP response from the target is received. The availability of the target system is evaluated upon receipt of each successful or unsuccessful probe result from each location.

Simple Monitoring is a subset of Simple Failover and Simple Load Balancing (SLB). You can run all the Simple Failover calls as a Simple Monitor call instead by ensuring that the Failover record information is removed from the body of the call. Examples will be provided for each call.

Simple Monitoring (SM) is designed to provide single resource record sites with a very basic website availability monitor. This monitor tracks if a website is available or unreachable, and alerts the customer to unavailability via email notification. This feature does not provide fail over assistance to an alternative record (i.e. All fail), nor does it provide any measurement statistics on the health of the website (beyond whether the site is available or down).

Simple Failover is configured to send an email alert whenever the status of a monitored endpoint changes. The email notification is sent to the Zone Owner's (the user that created the Zone/Domain) email address.

Creating an SF Pool

1. Select either an A or AAAA record type, and then click the +Add Pool button.

2. Select Simple Monitor / Failover (SF) from the Select Pool Type drop-down menu.

3. Provide the Host and the Points To fields.

4. Optionally you can provide the TTL value.

5. Provide the All Fail Record (the backup record).

6. Include the HTTP Test URL that will be used to verify the service is available.

7. Click Save when finished.

Editing an SF Pool

When editing a Simple Monitor / Failover Pool, the following options are available:

• Description – You can provide a description for the SF pool if you wish, but by default, it will display the pool name.

• TTL – You can set the Time to Live value for the pool (optional).

• Primary – The Primary Record for the pool. This can be changed at any point, and as long as you are serving the primary record, the Primary Serving section will display “Yes."

• Add Backup (Failover) – In the event that you have a backup record that you want to failover (fall back to) should your primary record fail, click in the checkbox. This will display the Failover field.

  • Failover – Provide the IP Address for the backup record that you want to failover to in the event your primary record fails.

  • If you are not currently in a failover situation, the Failover Serving will display “No.”

Probe Definition

When using Simple Monitor / Failover, an HTTP(S) probe is automatically configured for the Primary IP address. The Failover IP address is not probed.

This probe can be configured for GET or POST. It monitors the target system once every 300 seconds from each of four geographic regions. If POST is selected, the Transmitted Data section must be completed. Target system is the configured Primary IPv4 address.

• HTTP Test URL – Provide the URL that you wish to run the probe against.

• HTTP Method – You can select either GET in an attempt to retrieve data from the test probe, or POST to send data to the URL with the test probe.

  • If you select POST, the Transmitted Data field will appear, allowing you to specify the data you wish to send.

• Search String – You can provide a specific search string that should be present in a test probe response for the probe to be considered successful.

• Region Failure Sensitivity – Allows you to specify the conditions under which UltraDNS will serve the All Fail Record instead of one of the Primary Records.

  • High - Probes in two or more regions are reporting failure of the probe target. 

  • Low - Probes in ALL (four) regions are reporting failure of the probe target.

• Click the Test Probe button once you have configured your probe details. The Probe result will display at the top of the screen once completed.

• Click Save if you made any alterations to the screen.

Manual Failover

In the event that you need to failover to your backup record, as long as you have specified the Failover record, you can click the Manual Failover button to begin the failover process.

1. Click the Manual Failover button.

2. Verify that the backup record you will be pointing to is correct.

3. Click the Yes button.

   1. As per the disclaimer, please allow at least 15 seconds to see the updated Primary Serving and Failover Serving status changes before proceeding.

4. Click Save when you are finished.

Undo Manual Failover

1. To “failback” to your Primary Record, first ensure that the Failover Serving status says “Yes.”

2. Next, make sure the Primary displays the correct IP Address.

3. Click the Undo Manual Failover button.

4. Ensure the details are correct, and then click the Yes button.

   1. As per the disclaimer, please allow at least 15 seconds to see the updated Primary Serving and Failover Serving status changes before proceeding.

5. Click Save when you are finished.