Oracle Traffic Director allows you to serve a custom server pool maintenance response code, and HTML page, when all the back-end servers are detected offline. Providing this type of message is better than having a gateway time-out, or creating other resources to host static content.
When maintenance is enabled for an origin server pool, then:
requests landing on it are aborted with a 503 response code, if both response-code and response-file are not configured.
requests landing on it are aborted with response-code value as the response code, if only response-code is specified.
requests landing on it are not aborted, but are responded to with a response-file content and response-code value as the response code, if both are specified.
running of a health-check on its origin servers is disabled.
When maintenance is not enabled for an origin server pool but no origin servers are configured or enabled, then:
requests landing on it are aborted with a 503 response code.
running of a health-check on its origin servers is disabled.
Monitoring of Statistics for Origin Server Pool in Maintenance
If the origin-server pool is in a maintenance state, there will be no statistics for the origin server pool and the origin servers belonging to the pool. Statistics will be available only for active origin server pools and active origin servers.
Enabling or Disabling Maintenance for an Origin-Server Pool Using the CLI
To enable maintenance for an origin-server pool, run the enable-maintenance command.
For example, the following command enables maintenance for the http-pool-1 origin-server pool, and specifies a response-code of 505. This command takes response-code and response-file as optional properties. A response-code of 200 is not allowed without a response-file.
tadm> enable-maintenance --config=test --origin-server-pool=http-pool-1 --response-code=505
To disable maintenance, use the disable-maintenance command:
tadm> disable-maintenance --config=test --origin-server-pool=http-pool-1
To return the enabled, response-file and response-code properties for the origin-server pool, use the get-maintenance-prop command:
tadm> get-maintenance-prop --config=test --origin-server-pool=http-pool-1
For information about enable-maintenance, disable-maintenance, and get-maintenance-prop, see the Oracle Traffic Director Command-Line Reference or run the commands with the --help option.