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These Caching DNS metric elements are available in the dashboard:
The DNS Queries Type dashboard element rendered as a line chart traces the number queries by type. The chart is available if you choose Caching DNS Metrics: DNS Queries Type in the Chart Selection list.
The resulting line chart plots the following trends:
This chart shows the number of incoming queries of type A, AAAA, CNAME, PTR, and others.
The CDNS Query Responses dashboard element rendered as line chart shows the number of responses with NOERROR, NODOMAIN, No Data, Other Errors, Secure, and Unsecure return codes. The display is available if you choose Caching DNS Metrics: DNS Queries Responses in the Chart Selection list.
The resulting line chart plots the following trends:
This chart shows the following:
In a normal scenario, NOERROR is the successful response code.
Check the CDNS server configuration if the errors are increasing.
The CDNS Incoming queries by dashboard element rendered as a line chart traces the TCP, IPv6, DNSSSEC, EDNS and Total queries. The chart is available if you choose Caching DNS Metrics: DNS Incoming Queries in the Chart Selection list.
The resulting line chart plots the following trends:
This chart shows the number of queries that were made using TCP, IPv6, and DNSSEC towards the CDNS server, number of queries that had an EDNS OPT record present, and the total number of queries received.
The CDNS Queries by Type dashboard element rendered as a line chart traces the average time to complete a recursive query and the median time to complete a query. The table is available if you choose Caching DNS Metrics: DNS Recursive Query Time in the Chart Selection list.
The resulting line chart plots the following trends:
Average indicates the time the server took to answer queries that needed recursive processing. Note that the queries that were answered from the cache are not in this average.
Median time indicates the median of the time the server took to answer the queries that needed recursive processing. The median means that 50% of the user queries were answered in less than this time. Because of big outliers (usually queries to non responsive servers), the average can be bigger than the median.
Check the connectivity and configuration for the name servers as forwarders or exception lists for the increasing values of the average and median time.
The DNS Caching dashboard element rendered as a line chart traces the cache hits and cache misses. The chart is available if you choose Caching DNS Metrics: DNS Caching in the Chart Selection list.
The resulting line chart plots the following trends:
This chart indicates the number of queries that were successfully answered using a cache lookup against the number of queries that needed recursive processing.
If the cache misses are increasing exponentially, check the CDNS logs for errors. Increasing rates of cache misses can indicate that not enough space is available in memory to store the cached queries for more efficient responses.
The Caching DNS General Indicators dashboard element shows the server state, its last and startup reload time, and the total resource record (RR) count. The table is available if you choose Caching DNS Metrics: Caching DNS General Indicators in the Chart Selection list.
The resulting line chart plots the following trends-test:
The data in this chart shows general server health and operational duration. The objective is to make decisions about the server, such as whether it might be time for another reload, perhaps warranted by the number of configured zones.
If the server state is Down, all the CDNS chart indicators show a red status box, so no data will be available. In the case of a server that is down, restart the server.
The DNS Caching Server Queries Per Second dashboard element, rendered as chart, displays queries per second for the Caching DNS server. This chart is available if you choose CDNS Metrics: DNS Caching Server Queries Per Second in the Chart Selection page.