CN110855466A

CN110855466A - Method for actively pushing update to client by DNS (Domain name Server)

Info

Publication number: CN110855466A
Application number: CN201811583161.2A
Authority: CN
Inventors: 陈政璋; 毛伟; 邢志杰
Original assignee: INTERNET DOMAIN NAME SYSTEM BEIJING ENGINEERING RESEARCH CENTER LLC
Current assignee: INTERNET DOMAIN NAME SYSTEM BEIJING ENGINEERING RESEARCH CENTER LLC
Priority date: 2018-12-24
Filing date: 2018-12-24
Publication date: 2020-02-28

Abstract

The invention discloses a method for actively pushing update to a client by a DNS (domain name system) server, which comprises the following steps: a client subscribes a concerned record list to a server; when a record is updated on a server, inquiring a list of clients subscribing the record, and actively pushing an update message to the clients in the list; the server sets a time-out threshold value and a retry number threshold value, and when the push updating message is time-out, the push is retried according to the retry number threshold value. The method for actively pushing the update to the client by the DNS server improves the real-time performance and efficiency of the client for obtaining the update data of the DNS server and reduces the server load and network flow generated by frequent query of the client.

Description

Method for actively pushing update to client by DNS (Domain name Server)

Technical Field

The invention belongs to the field of Internet domain name systems, relates to a data synchronization method, and particularly relates to a method for actively pushing updates to a client by a DNS (domain name system) server.

Background

The Domain Name System (DNS) is an important infrastructure of the internet, and is mainly responsible for conversion between Domain names and IP addresses, and the normal operation of the DNS System is a basis for normal operation of almost all network services such as web services and electronic mail services.

Now, the DNS client uses a query response mechanism to obtain the record data, the client actively sends a query request packet, and the server returns the requested record data in a response packet. To reduce server load, the client may cache the logged data without querying the server for a period of time.

However, the current request response mechanism has the following drawbacks: in order to query the latest recorded data in real time, the client must ignore the local cache, frequently query the DNS server, increase the server load, and generate redundant network traffic.

Disclosure of Invention

In order to solve the above technical problem, the present invention provides a method for a DNS server to actively push updates to a client, the method comprising:

the DNS client subscribes to a list of records of interest to the DNS server.

When the record on the server is updated, inquiring a list of clients subscribing the record, and actively pushing the update to the clients in the list.

The server sets a timeout threshold and a retry time threshold, and retries the push update when the push update is overtime.

Further, the DNS push update mechanism and the DNS query response mechanism may work simultaneously.

Further, the pushed updates include two message types, one being notification messages and the other being logging messages.

Furthermore, after the client obtains the notification message, firstly verifying the validity of the notification message, sending the updated DNS record in the query request notification to the server after the verification is passed, and replacing the locally stored DNS record with the record returned in the response packet;

furthermore, after the client obtains the record message, the validity of the message is firstly verified, and the locally cached DNS record is directly replaced after the verification is passed.

Still further, the method further comprises: the client sends a signal to the server to cancel the subscription concerns to end one or more subscriptions in the record list.

Further, when the client needs to perform domain name resolution, the client preferentially uses the locally stored DNS record, and when the local miss occurs, requests data from the server based on the DNS query response mechanism.

Compared with the prior art, the method for actively pushing the update to the client by the DNS improves the real-time performance and efficiency of the client for obtaining the DNS data update, and reduces the server load and network flow generated by frequent query of the client.

Drawings

FIG. 1 is a diagram illustrating a communication process between a DNS client and a server according to an embodiment of the present invention;

fig. 2 is a flowchart illustrating a working procedure of the DNS push server according to an embodiment of the present invention;

fig. 3 is a flowchart of the DNS subscription server according to the embodiment of the present invention.

Detailed Description

The present invention will be described in further detail below with reference to the accompanying drawings, but the present invention is not limited thereto.

In order to make the technical solutions of the present invention better understood, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Fig. 1 is a schematic communication process diagram of a method for actively pushing an update to a client by a DNS server according to the present invention, including:

a DNS client sets subscription requirements for a DNS, sends a request signal for subscribing a concerned record list to a server, and the server returns a confirmed message to the client after receiving the request;

the server sends a notification signal for pushing the update to the client, and the client returns a confirmed message to the server after receiving the update message;

the client cancels the subscription of the record list to the server, and the server returns a confirmation message, wherein the subscription cancellation can be partial or complete cancellation in the record list, the client can also change the related data in the record list according to the requirement, the changed data is retransmitted to the server, and the server confirms that the change is successful after receiving the change.

Fig. 2 is a server flowchart of the method provided by the present invention, which includes:

when the record of the server side is changed, a client side list subscribed with the record is inquired, and then an updating message is sent to each client side in the list. For each client, if the confirmation message is received, the updating process is ended; if the received confirmation message is overtime, the update message is retried to be sent according to the set threshold value of the retry times until the message is successfully received or the client side is confirmed to be incapable of receiving, for example, the message receiving time is set to be 2 minutes, when the confirmation signal of the client side is still not received after 2 minutes, the push signal is sent again at intervals of 5 minutes until the sending times reach 3 times, and if the confirmation of the client side is still not received, the push is abandoned; if the client misses or misses the subscription message sent by the server, the client needs to send a request for retransmitting the subscription record to the server again.

Fig. 3 is a flow chart of a client according to the method provided by the present invention, which includes:

a client subscribes a concerned record list to a server and monitors and receives update message push of the server;

when receiving the update message of the server, returning a confirmation message to indicate that the receiving is successful;

in addition, the client side can carry out validity check on the received updating message, if the updating message is an illegal message, the client side discards the illegal message, and if the updating message is legal, the client side carries out the next processing;

the client judges the type of the received updating message, if the updating message is a notification message, the client initiates DNS query of the record to the server through a query response mechanism, and updates local data storage by using the record in the response message; if the message is a record message, the record in the message is analyzed, and the local storage data storage is directly updated. Wherein, the DNS push update mechanism and the DNS query response mechanism can work simultaneously. When the client needs to perform domain name resolution, the locally stored DNS record is preferentially used, and when the local miss occurs, data is requested to the server based on a DNS query response mechanism, so that the work of the server can be reduced.

The foregoing description shows and describes several preferred embodiments of the invention, but as aforementioned, it is to be understood that the invention is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the inventive concept as expressed herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method for actively pushing updates to a client by a DNS (domain name server) is characterized by comprising the following steps:

a DNS client subscribes a concerned record list to a DNS server;

when a record is updated on the DNS server, a list of client sides subscribed to the record is inquired, and the update is actively pushed to the DNS client sides in the list.

2. The method for DNS server to actively push updates to a client according to claim 1, further comprising: and when the push updating message is overtime, retrying to push according to the set threshold value of the retrying times until the push is successful or the client cannot receive the push is confirmed.

3. The method for DNS server to proactively push update to a client of claim 2, wherein the DNS push update mechanism and the DNS query response mechanism can work simultaneously.

4. The method for DNS server to push updates to client proactively, according to claim 1, wherein the update messages that are pushed proactively by the DNS server DNS client include two types, one being notification messages and the other being record messages.

5. The active DNS server update method according to claim 4, wherein when the client obtains the notification message, the validity of the notification message is first verified, the server is queried for the updated DNS record in the notification after the verification is passed, and the locally stored DNS record is replaced with the record returned in the response packet.

6. The active push update method for DNS server to client end according to claim 4, wherein after the client end obtains the record message, firstly verifying the validity of the message, directly replacing the locally stored DNS record after the verification is passed, and discarding if the message is illegal.

7. The method of claim 2, wherein the method further comprises: the client sends a signal to the server to cancel the subscription concerns to end one or more subscriptions in the record list.

8. The method for actively pushing update to client by DNS server according to any of claims 1-7, wherein when the client needs domain name resolution, it preferentially uses locally stored DNS record, and when the local miss occurs, it requests data from the server based on DNS query response mechanism.