Windows DNS Test

This test measures the workload and processing ability of the DNS component of the AD server.

Target of the test : An Active Directory or Domain Controller on Windows

Agent deploying the test : An internal agent

Outputs of the test : One set of results for every Active Directory that is being monitored

Configurable parameters for the test
Parameters	Description
Test period	This indicates how often should the test be executed.
Host	The host for which the test is to be configured.
Port	Refers to the port used by the Windows server.

Measurements made by the test
Measurement	Description	Measurement Unit	Interpretation
Total queries	The rate of queries received by DNS.	Reqs/sec	Indicates the workload of the DNS component of the AD server.
Total responses	The rate of responses from DNS to clients.	Resp/sec	Ideally, the total responses should match the total queries. Significant differences between the two can indicate that DNS is not able to handle the current workload.
Recursive queries	The rate of recursive queries successfully handled by DNS.	Reqs/sec	The ratio of recursive queries to total queries indicates the number of queries that required the DNS component on the AD server to communicate with other DNS servers to resolve the client requests.
Recursive query failures	The rate of recursive queries that could not be resolved by DNS.	Reqs/sec	Query failures can happen due to various reasons - e.g., requests from clients to invalid domain names/IP addresses, failure in the external network link thereby preventing a DNS server from communicating with other DNS servers on the Internet, failure of a specific DNS server to which a DNS server is forwarding all its requests, etc. A small percentage of failures is to be expected in any production environment. If a significant percentage of failures are happening, this could result in application failures due to DNS errors.
Recursive timeouts	The rate of recursive queries that failed because of timeouts.	Reqs/sec	Timeouts can happen because of a poor external link preventing a DNS server from communicating with others. In some cases, improper/invalid domain name resolution requests can also result in timeouts. DNS timeouts can adversely affect application performance and must be monitored continuously.
Zone transfers received	The number of zone transfer requests received by DNS.	Reqs	Zone transfers are resource intensive. Moreover, zone transfers to unauthorized clients can make an IT environment vulnerable to security attacks. Hence, it is important to monitor the number of zone transfer requests and responses on a periodic basis.
Zone transfers failed	The number of zone transfers that were not serviced by DNS in the last measurement period.	Reqs	Zone transfers may fail either because the DNS server does not have resources, or the request is not valid, or the client requesting the transfer is not authorized to receive the results.