Once the database mirroring is configured it is very important to monitor the performance of SQL Server and ldf size of the mirroring configured databases.network utilization of the Principle and Mirrored Server,you might get a question how many databases can be configured for log shipping, as per my experience 10 is the max value .
below are few important queries are used to monitor Mirroring environment
Query to know the state of Mirroring
select name as Endpoint ,state_desc from sys.database_mirroring_endpoints
Query to list Port’s related with Mirroring
select name,type_desc,port from sys.tcp_endpoints
Query to Know the Database Timeout in
select mirroring_connection_timeout from sys.database_mirroring
you can change the mirroring timeout of a database.