Many DBAs like to use "SELECT @@hostname" to identify a MySQL server. This can be problematic for a couple reasons. I've seen servers where the actual host name the result from "SELECT @@hostname" do not match. Someone had configured the MySQL hostname incorrectly and the result was the hostname of a different server. In my scripts I have to check for this and make sure the resolved hostname matches the value from "SELECT @@hostname" and if it does not then do additional checking.
Furthermore, when using RDS/Aurora, you cannot rely on the value of "SELECT @@hostname" because it will give some other value, such as a private IP which can be the same on multiple systems and is not the hostname you are looking for.
In your scripts you can run:
show global variables like 'aurora_version';
This will let you know that you are on an Aurora instance. Then you can use this query to get the aurora_server_id which is the closest thing to hostname.
show global variables like 'aurora_server_id';
The aurora_server_id is not going to be resolvable unless you add an alias to it in your DNS but you can get the full resolvable server address from the AWS RDS CLI.
If you are using Python you can use the boto3 RDS docs.
No comments:
Post a Comment