CONFIGURING DNS CLIENTS

• US 20150081926A1
• Filed: 09/16/2013
• Published: 03/19/2015
• Est. Priority Date: 09/16/2013
• Status: Active Grant

• Current Assignee: Netflix, Inc.
• Original Assignee: Netflix, Inc.
• Inventors: Nason, Benbuck, White, Jean-Marie
• Granted Patent: US 9,887,958 B2
• Time in Patent Office: Days
• US Class Current: 709/245
• CPC Class Codes: H04L 47/122 by diverting traffic away from congested entities
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 61/5007 Internet protocol [IP] addresses
• CPC Class Codes: H04L 61/58 Caching of addresses or names
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/1036 Load balancing of requests to servers for services different from user content provisioning, e.g. load balancing across domain name servers

Abstract

Techniques are provided for increasing the efficiency and efficacy of DNS clients. In one technique, DNS clients log information about performance of one or more DNS servers that the DNS clients use to resolve DNS resolution requests. The DNS clients send, to a control server, performance data regarding the DNS resolution requests and/or subsequent connections to servers associated with resolved domain names. Based on the performance data, the control server sends, to one or more DNS clients, configuration data that adjusts the configuration of the DNS clients. For example, if a particular DNS server is taking a considerable amount of time to resolve DNS resolution requests from one or more DNS clients, then the control server may send, to a plurality of DNS clients, configuration data that indicates a different set of one or more DNS servers for the plurality of DNS clients to contact for subsequent DNS resolution requests.

Claims

1. A method comprising:

determining, at a control server that is remote relative to one or more DNS clients, performance data of one or more DNS servers to which the one or more DNS clients send DNS resolution requests;

based on the performance data, sending, from the control server to the one or more DNS clients, configuration instructions that, when processed by the one or more DNS clients, causes a configuration of each of the one or more DNS clients to change;

wherein the method is performed by one or more computing devices.

2. The method of claim 1, wherein determining the performance data comprises:

receiving, from a first DNS client, first performance data regarding the performance of the one or more DNS servers;

wherein the performance data includes the first performance data.

3. The method of claim 2, wherein sending the configuration instructions comprises sending the configuration instructions to a second DNS client from which performance data has not been received.

4. The method of claim 2, further comprising:

receiving, from a second DNS client that is different than the first DNS client, second performance data regarding the performance of the one or more DNS servers;

based on the first performance data and the second performance data, sending, to a third DNS client, configuration data that causes the third DNS client to use one or more second DNS servers that are different than the one or more first DNS servers to resolve DNS resolution requests.

5. The method of claim 1, wherein the performance data includes average latency of a plurality of DNS lookups or a number of failed DNS lookups.

6. A method comprising:

sending, from a DNS client, one or more DNS resolution requests to one or more DNS servers;

receiving, at the DNS client, one or more responses to the one or more DNS resolution requests;

storing, at the DNS client, based on the one or more responses, performance data regarding the performance of the one or more DNS servers,

sending, from the DNS client, the performance data to a control server that receives, from multiple DNS clients, data about the performance of a plurality of DNS servers;

wherein the method is performed by a computing device.

7. The method of claim 6, further comprising:

receiving, at the DNS client, configuration data from the control server;

changing, at the DNS client, a configuration of the DNS client based on the configuration data.

8. The method of claim 7, wherein:

the one or more DNS servers are one or more first DNS servers;

the configuration data indicates one or more second DNS servers that are different than the one or more first DNS servers;

changing the configuration includes storing DNS server data that indicates that the one or more second DNS servers are to be used for one or more subsequent DNS resolution requests.

9. The method of claim 7, wherein:

the configuration data indicates one or more of (a) a fallback time that indicates when the DNS client is to use one or more fallback DNS servers, (b) a time to live (TTL) with respect to the DNS client or with respect to a particular group of one or more DNS servers, or (c) a rank order that indicates an order in which the DNS client is to query DNS servers.

10. The method of claim 6, wherein the performance data indicates one or more (a) a time difference between sending the one or more DNS resolution requests and receiving the one or more responses or (b) an error rate associated with the one or more DNS servers.

11. The method of claim 6, further comprising:

in response to determining that an application has started, sending, from the DNS client, one or more second DNS resolution requests to one or more second DNS servers.

12. The method of claim 6, further comprising:

sending a DNS resolution request to a first DNS server;

sending the DNS resolution request to a second DNS server that is different than the first DNS server without waiting to receive a response to the DNS resolution request from the first DNS server.

13. The method of claim 6, further comprising:

storing, at the DNS client, a plurality of cache entries, each of which associates a hostname with an IP address, wherein each cache entry of the plurality of cache entries is associated with an expiration time;

based on a particular expiration time associated with a particular cache entry, sending, from the DNS client, to a DNS server, a DNS resolution request that indicates a particular hostname that is indicated by the particular cache entry.

14. The method of claim 13, wherein sending the DNS resolution request is performed in response to detecting that the particular expiration time is about to expire or recently expired.

15. The method of claim 6, further comprising:

storing, at the DNS client, first server data that identifies a first set of one or more DNS servers;

storing, at the DNS client, second server data that identifies a second set of one or more DNS servers;

sending, from the DNS client, one or more first DNS resolution requests to one or more DNS servers in the first set;

sending, from the DNS client, one or more subsequent DNS resolution requests to one or more DNS servers in the second set without sending the one or more subsequent DNS resolution requests to any DNS server in the first set.

16. The method of claim 15, further comprising:

storing, at the DNS client, second performance data regarding the performance of the first set of one or more DNS servers;

wherein sending the one or more subsequent DNS resolution requests to the one or more DNS servers in the second set is performed based on the second performance data.

17. One or more computer-readable media storing instructions which, when executed by one or more processors, cause:

determining, at a control server that is remote relative to one or more DNS clients, performance data of one or more DNS servers to which the one or more DNS clients send DNS resolution requests;

based on the performance data, sending, from the control server to the one or more DNS clients, configuration instructions that, when processed by the one or more DNS clients, causes a configuration of each of the one or more DNS clients to change.

18. The one or more computer-readable media of claim 17, wherein determining the performance data comprises:

receiving, from a first DNS client, first performance data regarding the performance of the one or more DNS servers;

wherein the performance data includes the first performance data.

19. The one or more computer-readable media of claim 18, wherein sending the configuration instructions comprises sending the configuration instructions to a second DNS client from which performance data has not been received.

20. The one or more computer-readable media of claim 18, wherein the instructions, when executed by the one or more processors, further cause:

receiving, from a second DNS client that is different than the first DNS client, second performance data regarding the performance of the one or more DNS servers;

based on the first performance data and the second performance data, sending, to a third DNS client, configuration data that causes the third DNS client to use one or more second DNS servers that are different than the one or more first DNS servers to resolve DNS resolution requests.

21. The one or more computer-readable media of claim 17, wherein the performance data includes average latency of a plurality of DNS lookups or a number of failed DNS lookups.

22. One or more computer-readable media storing instructions which, when executed by one or more processors, cause:

sending, from a DNS client, one or more DNS resolution requests to one or more DNS servers;

receiving, at the DNS client, one or more responses to the one or more DNS resolution requests;

storing, at the DNS client, based on the one or more responses, performance data regarding the performance of the one or more DNS servers,

sending, from the DNS client, the performance data to a control server that receives, from multiple DNS clients, data about the performance of a plurality of DNS servers.

23. The one or more computer-readable media of claim 22, wherein the instructions, when executed by the one or more processors, further cause:

receiving, at the DNS client, configuration data from the control server;

changing, at the DNS client, a configuration of the DNS client based on the configuration data.

24. The one or more computer-readable media of claim 23, wherein:

the one or more DNS servers are one or more first DNS servers;

the configuration data indicates one or more second DNS servers that are different than the one or more first DNS servers;

changing the configuration includes storing DNS server data that indicates that the one or more second DNS servers are to be used for one or more subsequent DNS resolution requests.

25. The one or more computer-readable media of claim 23, wherein:

the configuration data indicates one or more of (a) a fallback time that indicates when the DNS client is to use one or more fallback DNS servers, (b) a time to live (TTL) with respect to the DNS client or with respect to a particular group of one or more DNS servers, or (c) a rank order that indicates an order in which the DNS client is to query DNS servers.

26. The one or more computer-readable media of claim 22, wherein the performance data indicates one or more (a) a time difference between sending the one or more DNS resolution requests and receiving the one or more responses or (b) an error rate associated with the one or more DNS servers.

27. The one or more computer-readable media of claim 22, wherein the instructions, when executed by the one or more processors, further cause:

in response to determining that an application has started, sending, from the DNS client, one or more second DNS resolution requests to one or more second DNS servers.

28. The one or more computer-readable media of claim 22, wherein the instructions, when executed by the one or more processors, further cause:

sending a DNS resolution request to a first DNS server;

sending the DNS resolution request to a second DNS server that is different than the first DNS server without waiting to receive a response to the DNS resolution request from the first DNS server.

29. The one or more computer-readable media of claim 22, wherein the instructions, when executed by the one or more processors, further cause:

storing, at the DNS client, a plurality of cache entries, each of which associates a hostname with an IP address, wherein each cache entry of the plurality of cache entries is associated with an expiration time;

based on a particular expiration time associated with a particular cache entry, sending, from the DNS client, to a DNS server, a DNS resolution request that indicates a particular hostname that is indicated by the particular cache entry.

30. The one or more computer-readable media of claim 22, wherein sending the DNS resolution request is performed in response to detecting that the particular expiration time is about to expire or recently expired.

31. The one or more computer-readable media of claim 22, wherein the instructions, when executed by the one or more processors, further cause:

storing, at the DNS client, first server data that identifies a first set of one or more DNS servers;

storing, at the DNS client, second server data that identifies a second set of one or more DNS servers;

sending, from the DNS client, one or more first DNS resolution requests to one or more DNS servers in the first set;

sending, from the DNS client, one or more subsequent DNS resolution requests to one or more DNS servers in the second set without sending the one or more subsequent DNS resolution requests to any DNS server in the first set.

32. The one or more computer-readable media of claim 31, wherein the instructions, when executed by the one or more processors, further cause:

storing, at the DNS client, second performance data regarding the performance of the first set of one or more DNS servers;

wherein sending the one or more subsequent DNS resolution requests to the one or more DNS servers in the second set is performed based on the second performance data.