DNS query method and system based on cache aggregation and recursive server

Abstract

The invention discloses a DNS (Domain Name Server) query method and system based on cache aggregation and recursive servers, aiming at solving the problems caused by independent operation of each recursive server when a plurality of recursive servers jointly provide an analysis service for a client in the prior art. A mirror image cache center server is arranged between a plurality of recursive servers and an internet authoritative DNS (Domain Name Server) server and serves as a common second-level cache of the recursive servers; the DNS query method is applied to any recursive server, and comprises the following steps: receiving a DNS query request of a client, searching a matching item in a local cache, and returning a result to the client; if the local cache is not hit, the request is forwarded to a mirror image cache center server through non-recursive query, and a response result of the mirror image cache center server is received; according to the method, the aggregation of the cached data is realized by adopting a method of combining a traffic mirroring technology and a unified caching mechanism.

Description

Technical Field

[0001] The present application relates to the field of Internet technology, and in particular to a DNS query method based on cache aggregation. Background Art

[0002] In order to solve the problem of insufficient resolution performance of a single DNS server, or to achieve the effect of multiple disaster recovery, a group of recursive servers will be deployed in the network environment to jointly provide resolution services to the client. The client's request will be directed to a recursive server through traffic load balancing or other disaster recovery selection mechanisms. The receiving recursive server will perform the resolution processing and return the response result to the client.

[0003] Each recursive server operates independently and lacks the necessary coordination mechanism. This operation mode makes it impossible to achieve centralized management and aggregation of related caches, thereby failing to effectively reduce external query traffic, thereby increasing network burden and extending the delay time of domain name resolution. Summary of the invention

[0004] The present application provides a DNS query method, system and recursive server based on cache aggregation, aiming to solve the problem in the prior art that when multiple recursive servers jointly provide resolution services to a client, each recursive server operates independently.

[0005] In a first aspect, a DNS query method based on cache aggregation is provided, wherein the DNS query method is based on multiple clients, multiple recursive servers, an Internet authoritative DNS server, and a mirror cache center server, wherein the mirror cache center server is arranged between the multiple recursive servers and the Internet authoritative DNS server as a secondary cache shared by the multiple recursive servers; the DNS query method is applied to any of the recursive servers, and comprises:

[0006] Receive DNS query requests from clients, search for matching items in the local cache, and return the results to the client;

[0007] If the local cache does not hit, the request is forwarded to the mirror cache central server through non-recursive query, and the response result of the mirror cache central server is received;

[0008] If the mirror cache hits, the local cache is updated and the result is returned to the client;

[0009] If the mirror cache does not hit, a recursive query is initiated to the Internet authoritative DNS server, the response result is obtained from the Internet authoritative DNS server, the local cache is updated, and the result is returned to the client; the response traffic is synchronously forwarded to the mirror cache central server through traffic mirroring technology.

[0010] In a second aspect, a mirror cache query method is provided, wherein the mirror cache query method is applied to a mirror cache central server, wherein the mirror cache central server is arranged between a plurality of recursive servers and an Internet authoritative DNS server as a common secondary cache of the plurality of recursive servers; the mirror cache query method comprises:

[0011] Respond to non-recursive query requests from recursive servers, search for matching items in the mirror cache, and return the results to the recursive server;

[0012] If there is a miss, a miss result is returned, and the recursive server initiates a recursive query to the Internet authoritative DNS server, receives the response traffic synchronously forwarded by the recursive server through traffic mirroring technology, and updates the mirror cache.

[0013] The above solution may optionally further include: when the cache of the image cache center server is about to expire, actively initiating a recursive query and updating the image cache according to the query result.

[0014] In a third aspect, a DNS query system based on cache aggregation is provided, the system comprising a plurality of recursive servers and an Internet authoritative DNS server, the system further comprising a mirror cache center server, wherein:

[0015] Any of the recursive servers receives a DNS query request from a client, searches for a match in the local cache, and returns the result to the client; if the local cache does not hit, forwards the request to the mirror cache central server through a non-recursive query, and receives the response result from the mirror cache central server; if the mirror cache hits, updates the local cache, and returns the result to the client; if the mirror cache does not hit, initiates a recursive query to the Internet authoritative DNS server, obtains the response result from the Internet authoritative DNS server, updates the local cache, and returns the result to the client; synchronously forwards the response traffic to the mirror cache central server through traffic mirroring technology;

[0016] The mirror cache central server is set between multiple recursive servers and the Internet authoritative DNS server, and serves as a common secondary cache of the multiple recursive servers. It receives non-recursive query requests from recursive servers, searches for matching items in the mirror cache, and returns the results to the recursive server; if the mirror cache does not hit, the recursive server initiates a recursive query to the Internet authoritative DNS server, the recursive server obtains the response result, and the mirror cache central server receives the response traffic synchronously forwarded by the recursive server through the traffic mirroring technology, and updates the mirror cache.

[0017] The above solution may optionally further include: the image cache central server supports cache backup and recovery capabilities, and when the network is interrupted or the authoritative server fails, the historical image cache version is used to ensure the continuous operation of the business.

[0018] The above solution may optionally further include: the image cache central server supports an automatic cache refresh renewal mechanism; when the cache is about to expire, the image cache central server actively initiates a recursive query and updates the image cache according to the query result.

[0019] In a fourth aspect, a recursive server includes a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the DNS query method based on cache aggregation as described above.

[0020] In a fifth aspect, a mirror cache central server is provided, wherein the mirror cache central server is arranged between a plurality of recursive servers and an Internet authoritative DNS server, and serves as a common secondary cache of the plurality of recursive servers; the mirror cache central server executes the mirror cache query method as described above.

[0021] Compared with the prior art, this application has at least the following beneficial effects:

[0022] Based on further analysis and research of existing technical problems, this application recognizes that each recursive server operates independently and lacks the necessary coordination mechanism between each other. This mode of operation makes it impossible to achieve centralized management and aggregation of related caches, thereby failing to effectively reduce external query traffic, thereby increasing the network burden and extending the delay time of domain name resolution. What is more serious is that when the network is interrupted or the authoritative DNS server fails, due to the lack of data synchronization and historical backup mechanism between the recursive servers, it is impossible to respond in time using historical backup data. This not only seriously affects the normal user experience, but also weakens the backup effect of the Internet DNS, making it unable to play its due disaster recovery role in the face of sudden failures. This application realizes the aggregation of cached data and effectively reduces the traffic demand for external queries by adopting a method that combines traffic mirroring technology with a unified cache mechanism.

[0023] The image cache of this application has backup and recovery functions, ensuring business continuity and availability and avoiding business interruptions.

[0024] The image cache of this application also supports automatic refresh and renewal functions, thereby improving the hit rate of cached data and reducing parsing delays. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 An execution logic diagram of any DNS recursive server is provided for one embodiment of the present application.

[0026] Figure 2 An interactive diagram of a DNS query system based on cache aggregation provided for one embodiment of the present application.

[0027] Figure 3 FIG. 4 is a diagram of the internal structure of a recursive server in one embodiment. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0029] In the description of this application: unless otherwise specified, "plurality" means two or more. "Including", "comprising", "having" and other expressions also mean "not limited to" (certain units, components, materials, steps, etc.).

[0030] Based on further analysis and research of existing technical problems, this application recognizes that in order to solve the problem of insufficient resolution performance of a single DNS server, or to achieve the effect of multiple disaster recovery, a group of recursive servers will be deployed in the network environment to jointly provide resolution services to the client.

[0031] Each recursive server operates independently and lacks the necessary coordination mechanism. This operation mode makes it impossible to achieve centralized management and aggregation of related caches, thereby failing to effectively reduce external query traffic, thereby increasing network burden and extending the delay time of domain name resolution.

[0032] What is more serious is that when the network is interrupted or the authoritative DNS server fails, the lack of data synchronization and historical backup mechanism between the recursive servers makes it impossible to respond in time using historical backup data. This not only seriously affects the normal user experience, but also weakens the backup effect of the Internet DNS, making it unable to play its due disaster recovery role in the face of sudden failures.

[0033] This application aims to solve the problems caused by the independent operation of each recursive server and provide an optimization strategy for realizing the collaborative aggregation of DNS caches of multiple recursive servers to reduce repeated outgoing query traffic and reduce resolution latency.

[0034] In one embodiment, reference Figure 1, provides a DNS query method based on cache aggregation, the DNS query method is based on multiple clients, multiple recursive servers, an Internet authoritative DNS server and a mirror cache center server, wherein the mirror cache center server is set between the multiple recursive servers and the Internet authoritative DNS server as a secondary cache shared by the multiple recursive servers; the DNS query method is applied to any recursive server, including:

[0035] Receive DNS query requests from clients, search for matching items in the local cache, and return the results to the client;

[0036] If the local cache does not hit, the request is forwarded to the mirror cache central server through non-recursive query, and the response result of the mirror cache central server is received;

[0037] If the mirror cache hits, the local cache is updated and the result is returned to the client;

[0038] If the mirror cache does not hit, a recursive query is initiated to the Internet authoritative DNS server, the response result is obtained from the Internet authoritative DNS server, the local cache is updated, and the result is returned to the client; the response traffic is synchronously forwarded to the mirror cache central server through traffic mirroring technology.

[0039] In this embodiment, when the DNS server receives a query request, it will first search in the local cache. If no match is found, the server will forward the request to the mirror cache by means of a non-recursive query. As a secondary cache, the mirror cache will initiate a recursive query to the outside if it also fails to hit. Once the relevant data is obtained, it will update the local cache and reply to the client. The reply traffic will be synchronously forwarded to the mirror cache central server through traffic mirroring technology, thereby updating the mirror cache. If other recursive servers receive the same query request, but there is no corresponding record in their cache, they can find the required data in the mirror cache query link, so there is no need to perform external recursive queries.

[0040] In one embodiment, there are two recursive servers, identified as A and B respectively.

[0041] 1. When server A first receives a query request from client www.example.com, both the local cache and the mirror cache miss, thus triggering a recursive query. The query result is then synchronously stored in the local cache and mirror cache of server A, and the result is responded to the client.

[0042] 2. When server B first receives the query request from client www.example.com, the local cache misses. At this time, server B will forward the relevant request to the mirror cache center server. Since the mirror cache center server already has the result returned by the previous query from server A, server B will get the result from the mirror cache, store it in the local cache, and respond to the client. In this way, server B avoids initiating recursive queries externally, thereby effectively reducing external query traffic and reducing the delay of domain name resolution.

[0043] In one embodiment, a mirror cache query method is provided. The mirror cache query method is applied to a mirror cache central server. The mirror cache central server is set between multiple recursive servers and an Internet authoritative DNS server as a secondary cache shared by multiple recursive servers. The mirror cache query method includes:

[0044] Respond to non-recursive query requests from recursive servers, search for matching items in the mirror cache, and return the results to the recursive server;

[0045] If there is a miss, a miss result is returned, and the recursive server initiates a recursive query to the Internet authoritative DNS server, receives the response traffic synchronously forwarded by the recursive server through traffic mirroring technology, and updates the mirror cache.

[0046] In one embodiment, when the cache of the image cache center server is about to expire, a recursive query is initiated proactively, and the image cache is updated according to the query result.

[0047] In one embodiment, reference Figure 2 , provides a DNS query system based on cache aggregation, the system includes multiple recursive servers and an Internet authoritative DNS server, the system also includes a mirror cache center server, wherein:

[0048] Any recursive server receives the DNS query request from the client, searches for matching items in the local cache, and returns the results to the client; if the local cache does not hit, the request is forwarded to the mirror cache center server through a non-recursive query, and the response result from the mirror cache center server is received; if the mirror cache hits, the local cache is updated and the result is returned to the client; if the mirror cache does not hit, a recursive query is initiated to the Internet authoritative DNS server, the response result is obtained from the Internet authoritative DNS server, the local cache is updated, and the result is returned to the client; the response traffic is synchronously forwarded to the mirror cache center server through traffic mirroring technology.

[0049] The mirror cache central server is set between multiple recursive servers and the Internet authoritative DNS server. As a common secondary cache for multiple recursive servers, it receives non-recursive query requests from recursive servers, searches for matching items in the mirror cache, and returns the results to the recursive server; if the mirror cache does not hit, the recursive server initiates a recursive query to the Internet authoritative DNS server, the recursive server obtains the response result, and the mirror cache central server receives the response traffic synchronously forwarded by the recursive server through traffic mirroring technology, and updates the mirror cache.

[0050] In this embodiment, the Internet authoritative DNS server includes a root domain name server, a top-level domain name server, and an authoritative domain name server. The recursive server initiates a recursive query request and obtains a response result through an iterative query process with these Internet authoritative DNS servers. The recursive server first initiates a query to the root domain name server, and based on the information provided by the root domain name server, continues to query the appropriate top-level domain name server, and finally reaches the authoritative domain name server responsible for the specific domain name, thereby obtaining the final response result.

[0051] In this embodiment, the response data received by multiple recursive servers are forwarded to the mirror cache central server through bypass traffic mirroring technology. Subsequently, the mirror cache server is responsible for parsing the data packets and updating and storing the parsed response results in a unified cache system.

[0052] In this embodiment, by adopting a method combining traffic mirroring technology with a unified cache mechanism, cache data aggregation is achieved and the traffic demand for external queries is effectively reduced.

[0053] In one embodiment, it also includes: the image cache center server supports cache backup and recovery capabilities, and when the network is interrupted or the authoritative server fails, the historical image cache version is used to ensure the continuous operation of the business.

[0054] In this embodiment, the image cache center server can support cache backup and recovery capabilities, so that when the network is interrupted or the authoritative server fails, the user can use the historical image cache version to restore the system according to the current system status to ensure the continuous operation of the business, thereby avoiding business interruptions and ensuring business continuity and availability.

[0055] In one embodiment, it also includes: the image cache center server supports an automatic cache refresh renewal mechanism. When the cache is about to expire, the image cache center server actively initiates a recursive query and updates the image cache according to the query result.

[0056] In this embodiment, the image cache center server supports an automatic cache refresh renewal mechanism. When the cache is about to expire, it actively initiates a recursive query and updates the cache based on the query results, thereby improving the cache hit rate and further reducing the resolution delay.

[0057] In one embodiment, a recursive server is provided, whose internal structure diagram can be as follows: Figure 3 As shown. The computer device includes a processor, a memory and a network interface connected through a system bus. The processor of the computer device is used to provide computing and control capabilities, and the network interface is used to communicate with an external terminal through a network connection. The computer device loads and runs a computer program to implement the above-mentioned DNS query method based on cache aggregation.

[0058] Those skilled in the art will understand that Figure 3 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0059] In one embodiment, a mirror cache central server is provided. The mirror cache central server is set between multiple recursive servers and the Internet authoritative DNS server as a common secondary cache for multiple recursive servers; the mirror cache central server executes the above-mentioned mirror cache query method.

[0060] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A DNS query method based on cache aggregation, characterized in that: The DNS query method is based on multiple clients, multiple recursive servers, an Internet authoritative DNS server, and a mirror cache center server, wherein the mirror cache center server is set between the multiple recursive servers and the Internet authoritative DNS server as a secondary cache shared by the multiple recursive servers; the DNS query method is applied to any of the recursive servers, including: Receive DNS query requests from clients, search for matching items in the local cache, and return the results to the client; If the local cache does not hit, the request is forwarded to the mirror cache central server through non-recursive query, and the response result of the mirror cache central server is received; If the mirror cache hits, the local cache is updated and the result is returned to the client; If the mirror cache does not hit, a recursive query is initiated to the Internet authoritative DNS server, the response result is obtained from the Internet authoritative DNS server, the local cache is updated, and the result is returned to the client; the response traffic is synchronously forwarded to the mirror cache central server through traffic mirroring technology.

2. A mirror cache query method, characterized in that: The mirror cache query method is applied to a mirror cache central server, which is set between multiple recursive servers and an Internet authoritative DNS server as a common secondary cache of the multiple recursive servers; The image cache query method comprises: Respond to non-recursive query requests from recursive servers, search for matching items in the mirror cache, and return the results to the recursive server; If there is a miss, a miss result is returned, and the recursive server initiates a recursive query to the Internet authoritative DNS server, receives the response traffic synchronously forwarded by the recursive server through traffic mirroring technology, and updates the mirror cache.

3. The image cache query method according to claim 2, characterized in that: Also includes: When the cache of the image cache center server is about to expire, a recursive query is initiated actively and the image cache is updated according to the query results.

4. A DNS query system based on cache aggregation, the system comprising a plurality of recursive servers and an Internet authoritative DNS server, characterized in that: The system also includes an image cache central server, wherein: Any of the recursive servers receives a DNS query request from a client, searches for a match in the local cache, and returns the result to the client; if the local cache does not hit, forwards the request to the mirror cache central server through a non-recursive query, and receives the response result from the mirror cache central server; if the mirror cache hits, updates the local cache, and returns the result to the client; if the mirror cache does not hit, initiates a recursive query to the Internet authoritative DNS server, obtains the response result from the Internet authoritative DNS server, updates the local cache, and returns the result to the client; synchronously forwards the response traffic to the mirror cache central server through traffic mirroring technology; The mirror cache central server is set between multiple recursive servers and the Internet authoritative DNS server, and serves as a common secondary cache of the multiple recursive servers. It receives non-recursive query requests from recursive servers, searches for matching items in the mirror cache, and returns the results to the recursive server; if the mirror cache does not hit, the recursive server initiates a recursive query to the Internet authoritative DNS server, the recursive server obtains the response result, and the mirror cache central server receives the response traffic synchronously forwarded by the recursive server through the traffic mirroring technology, and updates the mirror cache.

5. The DNS query system based on cache aggregation according to claim 4 is characterized in that: Also includes: The image cache central server supports cache backup and recovery capabilities. When the network is interrupted or the authoritative server fails, the historical image cache version is used to ensure the continuous operation of the business.

6. The DNS query system based on cache aggregation according to claim 4, characterized in that: Also includes: The mirror cache central server supports a cache automatic refresh renewal mechanism. When the cache is about to expire, the mirror cache central server actively initiates a recursive query and updates the mirror cache according to the query results.

7. A recursive server, comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method of claim 1.

8. A mirror cache center server, characterized in that: The mirror cache central server is set between multiple recursive servers and the Internet authoritative DNS server, serving as a common secondary cache for the multiple recursive servers; the mirror cache central server executes the mirror cache query method as described in claim 2.

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