DNS condition query optimization method and system based on RRset abstract

Abstract

The invention discloses a DNS (Domain Name Server) condition query optimization method and system based on an RRset abstract. According to the method, a data abstract is generated for each RRset through an authoritative server, and a cache abstract is carried for comparison when a recursive server queries, so that conditional query is realized. And the authoritative server returns an empty response and a new abstract or complete RRset data and a new abstract according to a comparison result, and the recursive server updates the local cache according to the empty response and the new abstract. By reducing redundant data transmission, bandwidth resources are remarkably saved, the cache consistency is enhanced, and the dirty cache problem caused by TTL expiration is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of domain name system protocol optimization, and in particular to a DNS conditional query optimization method and system based on RRset summary. Background Art

[0002] In the existing Domain Name System (DNS) protocol, every time a recursive server queries an authoritative server, the authoritative server must return a complete resource record (RR), regardless of whether its local cache is valid. This results in significant bandwidth waste. For example, when CDN providers frequently update their node IP addresses, numerous repeated queries result in the transmission of the same data. Furthermore, the DNS protocol relies on a TTL (Time to Live) expiration mechanism to manage caches, failing to proactively verify cache validity. This can lead to dirty caches, where DNS records are updated but the TTL hasn't expired. In high-concurrency query scenarios, authoritative servers must frequently generate complete responses, straining CPU and bandwidth resources. Existing optimization solutions, such as DNS TTL, HTTP ETag, DNSSEC RRSIG, and incremental transfer (IXFR), all have limitations. DNS TTL passively relies on time-based caching and cannot dynamically detect data changes. HTTP ETag, based on the HTTP stateful protocol, is not well-suited to the DNS hierarchical architecture and stateless query mechanism. DNSSEC RRSIG uses signatures to ensure data integrity, but does not optimize data transmission efficiency. IXFR relies on SOA sequence number synchronization, which is only suitable for sequential updates and cannot handle non-sequential changes. Therefore, the existing DNS protocol lacks a dynamic conditional query mechanism, cannot skip redundant transmissions through summary comparison, has low computational efficiency, and poor compatibility. Summary of the Invention

[0003] Based on this, an embodiment of the present application provides a DNS conditional query optimization method and system based on RRset summary. This application significantly saves bandwidth resources by reducing redundant data transmission, while enhancing cache consistency and avoiding dirty cache problems caused by TTL expiration.

[0004] In a first aspect, a method for optimizing DNS conditional queries based on RRset summaries is provided, the method comprising:

[0005] The authoritative server generates at least one data summary for each resource record set;

[0006] The recursive server carries the cached digest of the target resource record set in the query request;

[0007] After receiving the query request, the authoritative server compares the cached digest in the request with the digest of the corresponding resource record set stored locally;

[0008] Based on the comparison results, the authoritative server returns a corresponding response. If the comparison results are consistent, an empty Answer Section and a new summary are returned. If the comparison results are inconsistent, the complete resource record set data and a new summary are returned.

[0009] The recursive server updates its local cache based on the authoritative server's response.

[0010] Optionally, the authoritative server generates at least one data summary for each resource record set, including:

[0011] The authoritative server generates at least one data summary for each resource record set when a full or incremental transfer is completed;

[0012] When a dynamic update operation affects a target resource record set, the authoritative server regenerates a data digest of the resource record set; wherein the data digest is generated using a hash algorithm, the hash algorithm includes at least SHA-256, and supports multiple algorithm digests to reduce collision risks.

[0013] Optionally, the recursive server carries a cache summary of the target resource record set in the query request, including:

[0014] The recursive server obtains the cached digest of the target resource record set from its local cache;

[0015] The recursive server appends the cache digest to the query request using the EDNS0 extension field. The format of the EDNS0 extension field is "domain name|type|category|algorithm:digest value", supporting single-algorithm or multi-algorithm digests.

[0016] If the recursive server queries the target resource record set for the first time and the corresponding cache digest does not exist in the local cache, the cache digest is not carried.

[0017] Optionally, the authoritative server compares the cache digest in the request with the digest of the corresponding resource record set stored locally, including:

[0018] The authoritative server resolves the EDNS0 extension field in the query request and extracts the cached summary of the target resource record set;

[0019] The authoritative server compares the extracted cache digest with the digest of the corresponding resource record set stored locally;

[0020] If the comparison results are consistent, the authoritative server determines that the target resource record set has not changed; if the comparison results are inconsistent, the authoritative server determines that the target resource record set has changed.

[0021] Optionally, the authoritative server returns a corresponding response based on the comparison result, including:

[0022] If the comparison results are consistent, the authoritative server returns an empty Answer Section and returns a new summary through the EDNS0 option;

[0023] If the comparison results are inconsistent, the authoritative server returns the complete resource record set data and a new summary;

[0024] A new digest is recomputed by the authoritative server when the response is generated to reflect the current state of the resource record set.

[0025] Optionally, the recursive server updates the local cache according to the response from the authoritative server, including:

[0026] The recursive server receives the response from the authoritative server and parses the EDNS0 option or Answer Section in the response.

[0027] If the response contains an empty Answer Section, the recursive server updates the digest of the resource record set in its local cache with the new digest;

[0028] If the response contains complete resource record set data, the recursive server updates the resource record set data and digest in its local cache with the new data and digest;

[0029] The recursive server returns the updated resource record set data to the client.

[0030] In a second aspect, a DNS conditional query optimization system based on RRset summary is provided, the system comprising:

[0031] The authoritative server generates at least one data summary for each resource record set. Upon receiving a query request, the authoritative server compares the cached summary in the request with the locally stored summary of the corresponding resource record set and returns a corresponding response based on the comparison result. If the comparison results are consistent, an empty Answer Section and a new summary are returned. If the comparison results are inconsistent, the complete resource record set data and a new summary are returned.

[0032] A recursive server carries the cached digest of the target resource record set in a query request and updates the local cache based on the authoritative server's response.

[0033] In a third aspect, an electronic device is provided, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the DNS conditional query optimization method described in any one of the first aspects is implemented.

[0034] In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the DNS conditional query optimization method described in any one of the first aspects is implemented.

[0035] In a fifth aspect, a computer program product is provided, on which a computer program is stored. When the computer program is executed by a processor, the DNS conditional query optimization method described in any one of the first aspects is implemented.

[0036] The beneficial effects of the technical solutions provided in the embodiments of the present application include at least:

[0037] (1) By including the cache digest in the recursive server query request, the authoritative server returns the complete data only when the RRset changes, otherwise it returns an empty response and a new digest. This greatly reduces redundant data transmission, especially in high-concurrency query scenarios, significantly reducing network bandwidth consumption and improving overall system efficiency.

[0038] (2) By using the hash digest comparison mechanism, the recursive server can accurately determine whether the locally cached RRset is valid. Even when DNS records are frequently updated, it can obtain the latest data in a timely manner, avoiding the dirty cache problem caused by the TTL expiration mechanism and ensuring the accuracy and reliability of DNS resolution results.

[0039] (3) The authoritative server does not need to generate a complete response for each query. It returns complete data only when the RRset changes, which effectively reduces the pressure on CPU and bandwidth resources, improves the server's processing power and response speed, and enhances the scalability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other implementation drawings based on the provided drawings without inventive effort.

[0041] Figure 1 A flowchart of the steps of a DNS conditional query optimization method based on RRset summary provided in an embodiment of the present application;

[0042] Figure 2 A flowchart of the protocol interaction provided in the embodiment of the present application;

[0043] Figure 3 This is a diagram of the DNS conditional query optimization system architecture provided in an embodiment of the present application;

[0044] Figure 4A schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0046] In the description of the present invention, the terms "comprise", "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may also include other steps or units that are not explicitly listed but are inherent to these processes, methods, products or apparatuses, or steps or units that are added based on further optimization solutions conceived by the present invention.

[0047] To facilitate understanding of this embodiment, a DNS conditional query optimization method based on RRset summary disclosed in an embodiment of the present application is first introduced in detail.

[0048] The present application relates to Domain Name System (DNS) protocol optimization technology, specifically to a mechanism for generating data summaries by dividing resource record sets (RRsets) and carrying cache summaries on recursive servers to achieve efficient conditional queries, which is used to reduce redundant data transmission, improve resolution efficiency, and enhance cache consistency.

[0049] The following problems exist in the optimization of the existing Domain Name System (DNS) protocol:

[0050] Redundant data transmission: In the current DNS protocol, every time a recursive server queries an authoritative server, the authoritative server must return the complete resource record (RR), regardless of whether the local cache is valid. This results in wasted bandwidth. For example, when a CDN service provider frequently updates its node IP, a large number of repeated queries and transmissions of the same data are performed.

[0051] Cache update delay: Relying on the TTL expiration mechanism, the cache validity cannot be actively verified, which may lead to dirty cache (for example, the DNS record has been changed but the TTL has not expired).

[0052] High load pressure: Authoritative servers need to frequently generate complete responses in high-concurrency query scenarios, leading to CPU and bandwidth resource constraints. Table 1 provides a table of related technical attempts and limitations:

[0053] Table 1 Related technical attempts and limitations

[0054] technology limitation DNSTTL Passively relies on time to control the cache and cannot dynamically perceive data changes. HTTP ETag Based on the HTTP state protocol, it cannot adapt to the DNS layered architecture and stateless query mechanism. DNSSECRRSIG Data integrity is guaranteed by signatures, but data transmission efficiency is not optimized. Incremental transfer (IXFR) Relying on SOA serial number synchronization, it is only applicable to sequential update scenarios and cannot handle non-continuous changes.

[0055] It can be seen that the relevant technical limitations include:

[0056] Protocol rigidity: The DNS protocol lacks a dynamic conditional query mechanism and cannot skip redundant transmissions through summary comparison.

[0057] Low computational efficiency: Existing optimization solutions (such as IXFR) require maintaining a global sequence number and cannot accurately locate the changed RRset.

[0058] Poor compatibility: Extended features (such as DNS Cookies) only address security issues and do not optimize data transmission.

[0059] Please refer to Figure 1 , which shows a flowchart of a DNS conditional query optimization method based on RRset summary provided by an embodiment of the present application. The method may include the following steps:

[0060] S1, the authoritative server generates at least one data summary for each resource record set.

[0061] Specifically, the authoritative server generates at least one data summary for each resource record set when the full transfer or incremental transfer is completed;

[0062] When a dynamic update operation affects a target resource record set, the authoritative server regenerates a data digest of the resource record set; wherein the data digest is generated using a hash algorithm, the hash algorithm includes at least SHA-256, and supports multiple algorithm digests to reduce collision risks.

[0063] S2, the recursive server carries the cached digest of the target resource record set in the query request.

[0064] Specifically, the recursive server obtains the cache digest of the target resource record set from its local cache;

[0065] The recursive server appends the cache digest to the query request using the EDNS0 extension field. The format of the EDNS0 extension field is "domain name|type|category|algorithm:digest value", supporting single-algorithm or multi-algorithm digests.

[0066] S3, after receiving the query request, the authoritative server compares the cached summary in the request with the summary of the corresponding resource record set stored locally.

[0067] Specifically, the authoritative server parses the EDNS0 extension field in the query request and extracts the cached summary of the target resource record set;

[0068] S4: Based on the comparison results, the authoritative server returns a corresponding response.

[0069] The authoritative server compares the extracted cache digest with the digest of the corresponding resource record set stored locally;

[0070] If the comparison results are consistent, the authoritative server determines that the target resource record set has not changed; if the comparison results are inconsistent, the authoritative server determines that the target resource record set has changed.

[0071] S5, the recursive server updates the local cache based on the response from the authoritative server.

[0072] Specifically, the recursive server receives the response from the authoritative server and parses the EDNS0 option or AnswerSection in the response;

[0073] If the response contains an empty Answer Section, the recursive server updates the digest of the resource record set in its local cache with the new digest;

[0074] If the response contains complete resource record set data, the recursive server updates the resource record set data and digest in its local cache with the new data and digest;

[0075] The recursive server returns the updated resource record set data to the client.

[0076] From the above, it can be seen that the innovation of this application lies in:

[0077] (1) RRset summary generation:

[0078] The authoritative server independently generates at least one strong hash digest (such as SHA-256) for each RRset. The update time includes:

[0079] When a full transfer (AXFR) or incremental transfer (IXFR) is completed;

[0080] When a dynamic update (nsupdate) affects the target RRset.

[0081] Multi-algorithm digests (such as SHA-256+BLAKE3) are supported to reduce the risk of collisions, but are not mandatory.

[0082] (2) Conditional query and response mechanism:

[0083] The recursive server carries the cached digest of the target RRset in the query (via the EDNS0 extension field);

[0084] After comparing the digests, the authoritative server:

[0085] Consistent → Returns an empty Answer Section + a new summary (make sure to recursively update the local cache);

[0086] Inconsistent → Return full RRset + new summary.

[0087] (3) Protocol extension design:

[0088] Added EDNS0 option RRDIGEST, encoding format is domain name|type|category|algorithm:digest value (multiple digests are separated by commas);

[0089] Compatible with traditional DNS servers and supports automatic fallback to standard queries.

[0090] Technical effects include:

[0091] Bandwidth savings: If the target RRset does not change, the response traffic is reduced by more than 60% (the size of an empty response is about 50 bytes).

[0092] Strong consistency: Data integrity is ensured through hash digests, and the probability of collision is negligible (such as 1 / 2^256 for SHA-256).

[0093] like Figure 2 A protocol interaction flow chart is provided. Another optional implementation method of this application is provided below:

[0094] 1. Summary generation rules.

[0095] Authoritative server logic:

[0096] Each RRset generates a summary independently. The example storage format is:

[0097] ;RRset data

[0098] www.example.com.300IN A 192.0.2.1

[0099] www.example.com.300IN A 192.0.2.2

[0100] ; Corresponding summary record (single algorithm)

[0101] _digest.www.example.com.300IN TXT"sha256=9f86d081..."

[0102] Multiple algorithm support (optional):

[0103] ;Multi-algorithm summary record

[0104] _digest.www.example.com.300IN TXT"sha256=9f86d081...,blake3=4a8c8a..."

[0105] 2. Protocol extension design.

[0106] ;;OPT pseudo record

[0107] ; OPTION-CODE = RRDIGEST (custom code)

[0108] ; Data format: domain name | type | category | algorithm 1: summary value | algorithm 2: summary value...

[0109] ; Example (single summary):

[0110] ;RRDIGEST=www.example.com|A|IN|sha256:9f86d081...

[0111] ; Example (multiple snippets):

[0112] ;RRDIGEST=www.example.com|A|IN|sha256:9f86d081...,blake3:4a8c8a...

[0113] 3. Request and response process.

[0114] Recursive server first query: Authoritative returns full RRset + summary (via EDNS0 or TXT record).

[0115] Subsequent conditional queries: recursively carry the cache digest, and return an empty response or new data after authoritative comparison.

[0116] Summary update trigger: The authority generates a new summary when the RRset changes, and the recursion automatically synchronizes through the response.

[0117] From the above, we can see that the fault tolerance and compatibility of this application are specifically as follows:

[0118] 1. Fault-tolerant mechanism.

[0119] Digest format error: If the authority cannot parse the digest in the request, return the full data and append a new digest.

[0120] Expiration of old digests: The recursive server automatically replaces the old value after receiving the new digest, without manual intervention.

[0121] 2. Compatibility design.

[0122] Traditional DNS support:

[0123] The authoritative server declares the digest algorithms it supports in the response (EDNS0 field Supported-Digest-Algorithms);

[0124] When a recursive server detects that the authority does not support RRDIGEST, it automatically falls back to a standard query.

[0125] Implementation cases include:

[0126] Scenario: Dynamic CDN node switching.

[0127] Authoritative server: The CDN provider updates the A record for cdn-node.example.com (the IP address switches from 192.0.2.1 to 192.0.2.2), triggering an update to the RRset summary.

[0128] Recursive Server:

[0129] The first query obtains the IP 192.0.2.1 and the digest sha256:old_hash;

[0130] Subsequent queries carry sha256:old_hash, and the authority detects a digest mismatch and returns the new IP 192.0.2.2 and the digest sha256:new_hash.

[0131] Benefit comparison:

[0132] Traditional DNS: Each query returns 120 bytes (including 2 A records);

[0133] The present invention: 90% of queries return 50 bytes (empty response + digest), and traffic is reduced by 58%.

[0134] Please refer to Figure 3 , which shows a block diagram of a DNS conditional query optimization system based on RRset summaries provided by an embodiment of the present application. The system may include:

[0135] The authoritative server generates at least one data summary for each resource record set. Upon receiving a query request, the authoritative server compares the cached summary in the request with the locally stored summary of the corresponding resource record set and returns a corresponding response based on the comparison result. If the comparison results are consistent, an empty Answer Section and a new summary are returned. If the comparison results are inconsistent, the complete resource record set data and a new summary are returned.

[0136] A recursive server carries the cached digest of the target resource record set in a query request and updates the local cache based on the authoritative server's response.

[0137] For the specific limitations of the DNS conditional query optimization system based on RRset summary, please refer to the limitations of the DNS conditional query optimization method based on RRset summary above, which will not be repeated here. The various modules in the above-mentioned DNS conditional query optimization system based on RRset summary can be implemented in whole or in part through software, hardware and their combination. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0138] In one embodiment, an electronic device is provided. The electronic device may be a computer, and its internal structure diagram may be as follows: Figure 4 As shown. The electronic device includes a processor, a memory and a network interface connected via a system bus. The processor of the device is used to provide computing and control capabilities. The memory of the device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to optimize data based on DNS conditional queries of RRset summaries. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a DNS conditional query optimization method based on RRset summaries is implemented.

[0139] Those skilled in the art will understand that Figure 4 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 shown in the figure, or combine certain components, or have a different component arrangement.

[0140] In one embodiment of the present application, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned DNS conditional query optimization method based on RRset summary are implemented.

[0141] In one embodiment of the present application, a computer program product is provided, including a computer program / instruction, which implements the steps of the above-mentioned DNS conditional query optimization method based on RRset summary when the computer program is executed by a processor.

[0142] The computer-readable storage medium and computer program product provided in this embodiment have similar implementation principles and technical effects to those of the above-mentioned method embodiments, and are not described in detail here.

[0143] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in M forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (SyMchliMk) DRAM (SLDRAM), memory bus (RaMbus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0144] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned 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.

[0145] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A DNS conditional query optimization method based on RRset summary, characterized in that: The method comprises: The authoritative server generates at least one data summary for each resource record set; The recursive server carries the cached digest of the target resource record set in the query request; After receiving the query request, the authoritative server compares the cached digest in the request with the digest of the corresponding resource record set stored locally; Based on the comparison results, the authoritative server returns the corresponding response; if the comparison results are consistent, it returns an empty AnswerSection and a new summary; if the comparison results are inconsistent, it returns the complete resource record set data and a new summary; The recursive server updates its local cache based on the authoritative server's response.

2. The DNS conditional query optimization method according to claim 1, characterized in that: The authoritative server generates at least one data summary for each resource record set, including: The authoritative server generates at least one data summary for each resource record set when a full or incremental transfer is completed; When a dynamic update operation affects a target resource record set, the authoritative server regenerates a data digest of the resource record set; wherein the data digest is generated using a hash algorithm, the hash algorithm includes at least SHA-256, and supports multiple algorithm digests to reduce collision risks.

3. The DNS conditional query optimization method according to claim 1, characterized in that: The recursive server carries the cache digest of the target resource record set in the query request, including: The recursive server obtains the cached digest of the target resource record set from its local cache; The recursive server appends the cache digest to the query request using the EDNS0 extension field. The format of the EDNS0 extension field is "domain name|type|category|algorithm:digest value", supporting single-algorithm or multi-algorithm digests. If the recursive server queries the target resource record set for the first time and the corresponding cache digest does not exist in the local cache, the cache digest is not carried.

4. The DNS conditional query optimization method according to claim 1, characterized in that: The authoritative server compares the cache digest in the request with the digest of the corresponding resource record set stored locally, including: The authoritative server resolves the EDNS0 extension field in the query request and extracts the cached summary of the target resource record set; The authoritative server compares the extracted cache digest with the digest of the corresponding resource record set stored locally; If the comparison results are consistent, the authoritative server determines that the target resource record set has not changed; if the comparison results are inconsistent, the authoritative server determines that the target resource record set has changed.

5. The DNS conditional query optimization method according to claim 1, characterized in that: The authoritative server returns a corresponding response based on the comparison result, including: If the comparison results are consistent, the authoritative server returns an empty Answer Section and returns a new summary through the EDNS0 option; If the comparison results are inconsistent, the authoritative server returns the complete resource record set data and a new summary; A new digest is recomputed by the authoritative server when the response is generated to reflect the current state of the resource record set.

6. The DNS conditional query optimization method according to claim 1, characterized in that: The recursive server updates the local cache according to the response from the authoritative server, including: The recursive server receives the response from the authoritative server and parses the EDNS0 option or Answer Section in the response. If the response contains an empty Answer Section, the recursive server updates the digest of the resource record set in its local cache with the new digest; If the response contains complete resource record set data, the recursive server updates the resource record set data and digest in its local cache with the new data and digest; The recursive server returns the updated resource record set data to the client.

7. A DNS conditional query optimization system based on RRset summary, characterized in that: The system comprises: The authoritative server generates at least one data summary for each resource record set. Upon receiving a query request, the authoritative server compares the cached summary in the request with the locally stored summary of the corresponding resource record set and returns a corresponding response based on the comparison result. If the comparison result is consistent, an empty Answer Section and a new summary are returned. If the comparison result is inconsistent, the complete resource record set data and a new summary are returned. A recursive server carries the cached digest of the target resource record set in a query request and updates the local cache based on the authoritative server's response.

8. An electronic device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the method for optimizing DNS conditional queries according to any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium, characterized in that A computer program is stored thereon, and when the computer program is executed by a processor, the DNS conditional query optimization method according to any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the DNS conditional query optimization method according to any one of claims 1 to 6 is implemented.

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