Name server property tracking

A system comprising:

• one or more computing devices configured to interact with a non-transitory computer storage medium to perform operations comprising:
• generating, using one or more processors, a respective group of test queries for each domain name system server of a plurality of domain name system servers, each respective group of test queries including a plurality of test queries, wherein each test query in the respective group of test queries is configured to cause the domain name system server to generate a respective response and is associated with one or more features of the domain name system server to be determined by analyzing the respective response, and wherein the features associated with one test query are different from the features associated with another test query within each respective group, and a particular respective group of test queries is generated from queries that have been previously sent to the domain name system server;
• determining a respective time period, for each of the domain name system servers, to send the respective test queries for the domain name system server to the domain name system server, wherein the respective time period is determined based at least in part on a count of test queries sent to the domain name system server over a span of time and a count of responses to the test queries received from the domain name system server over the same span of time;
• for each domain name system server of the plurality of domain name system servers, sending the respective group of test queries to the domain name system server according to the respective determined time period;
• receiving responses to the test queries from the domain name system servers;
• determining one or more different features for each of the one or more of the domain name system servers based on the received responses to the test queries, the different features for each domain name system server based on the one or more features associated with each test query sent to the domain name system server;
• and
• generating one or more configuration records for use by a domain name system resolver process, the one or more configuration records based on the one or more different features of the domain name system servers and configured to control one or more aspects of how the domain name system resolver process sends domain name system queries to the domain name system servers.

A non-transitory computer storage medium encoded with a computer program, the program comprising instructions that when executed by data processing apparatus cause the data processing apparatus to perform operations comprising:

• generating, using one or more processors, a respective group of test queries for each domain name system server of a plurality of domain name system servers, each respective group including a plurality of test queries, wherein each test query in the respective group of test queries is configured to cause the domain name system server to generate a respective response, and wherein each test in the respective group of test queries is associated with one or more features of the domain name system server to be determined by analyzing the respective response, and wherein the features associated with one test query are different from the features associated with another test query, and a particular respective group of test queries is generated from queries that have been previously sent to the domain name system server;
• determining a respective time period, for each of the domain name system servers, to send the respective test queries for the domain name system server to the domain name system server, wherein the respective time period is determined based at least in part on a count of test queries sent to the domain name system server over a span of time and a count of responses to the test queries received from the domain name system server over the same span of time;
• for each domain name system server of the plurality of domain name system servers, sending the respective group of test queries to the domain name system server according to the respective determined time period;
• receiving responses to the test queries from the domain name system servers;
• determining one or more different features for each of the one or more of the domain name system servers based on the received responses to the test queries, the different features for each domain name system server based on the one or more features associated with each test query sent to the domain name system server;
• and
• generating one or more configuration records for use by a domain name system resolver process, the one or more configuration records based on the one or more different features of the domain name system servers, and the one or more configuration records configured to control one or more aspects of how the domain name system resolver process sends domain name system queries to the domain name system servers.