In this case, which of the following descriptions is correct?

The centralized networking scheme of three servers, as shown in the figure, the administrator found that only one of the three Agile Controllers in the resource pool was alive.

In this case, which of the following descriptions is correct? (Multiple Choice)

A . All three database servers cannot work properly, and only one of the three Agile Controllers in the resource pool is alive. In this case, all Agile Controller services are transferred to the surviving Agile Controller and can operate normally, and terminal identity authentication, access control, software distribution, patch installation, and asset management will not be affected.
B. After the Agile Controller is started, each Agile Controller will immediately read the database and save it on the local hard disk as a cache. If all databases become unavailable due to a failure, the Agile Controller will continue to maintain the operation of the Agile Controller service by using the cache saved at that time as the data source.
C. At this point, you can try to restart the surviving Agile Controller, and repair the database server when restarting.
D. At this time, the escape channel on the firewall has been opened.

Answer: AB