PHP version of micro-letter payment api.mch.weixin.qq.com Domain name resolution slow reason and solution _php skills

This article describes the PHP version of micro-letter payment api.mch.weixin.qq.com Domain name resolution slow reasons and solutions. Share to everyone for your reference, specific as follows:

Micro-credit Payment api.mch.weixin.qq.com domain name resolution is slow, resulting in very slow payment, so how to solve the problem of micro-letter payment slow, here to analyze together.

Have friends in the Aliyun host implementation of micro-credit payment logic, found that api.mch.weixin.qq.com parsing is too slow.

So there has been manual modification of the/etc/hosts, of course, which day micro-letter payment if a change in the room must be hung.

Our room also has similar problems, specifically recorded.

The code uses the curl to request the micro-letter, often times out, when using the wget test:

[root@01 tmp]# wget api.mch.weixin.qq.com--2016-06-18 14:51:03--http://api.mch.weixin.qq.com/resolving
Api.mch.weixin.qq.com ...

Domain name resolution A long time not come out

Test confirmation is IPv6 problem

To Wget plus-4, mandatory use of IPv4, if very soon, that is basically determined to be IPv6 caused the trouble.

[root@01 tmp]# wget-4 api.mch.weixin.qq.com--2016-06-18 17:03:52--http://api.mch.weixin.qq.com/resolving
Api.mch.weixin.qq.com ... 123.151.71.149, 123.151.79.109
connecting to api.mch.weixin.qq.com|123.151.71.149|:80 ... connected.

Code Analysis

Specifically write a code to test IPv6 parsing, using the system function Getaddrinfo:

 #include <stdio.h> #include <string.h> #include <netdb.h> #include ;iostream> #include <sys/types.h> #include <sys/types.h> #include <sys/socket.h> #include <
Arpa/inet.h> using namespace std;
  int main () {struct addrinfo hints,*answer,*curr,*p;
  int error;
  memset (&hints, 0, sizeof hints); hints.ai_family = Af_inet6;//af_unspec; Use Af_inet6 to force IPv6 hints.ai_socktype = Sock_stream;//sock_dgram; Sock_stream if ((Error = getaddrinfo ("api.mch.weixin.qq.com", NULL, &hints, &answer))!= 0) {fprintf (std
    Err, "getaddrinfo:%s\n", Gai_strerror (Error));
  return 1;
  else cout << "Success with a url\n";
  Char ipstr[16]; for (Curr = answer; Curr!= NULL; curr = curr->ai_next) {inet_ntop (af_inet,& (struct sockaddr_in *) (curr->
    AI_ADDR))->sin_addr), IPSTR, 16);
  printf ("%s\n", ipstr);
  } freeaddrinfo (answer);
return 0; }

Include header file

Netdb.h

Function Prototypes:

int getaddrinfo (const char hostname, const char service, const struct addrinfo *hints, struct addrinfo);

Parameter description:

Hints: Either a null pointer or a pointer to a ADDRINFO structure in which the caller fills in a hint about the type of information expected to return. For example, if the specified service supports both TCP and UDP, the caller can set the Ai_socktype member in the hints structure to sock_dgram so that only information that is appropriate for the datagram socket interface is returned. And whether IPv6 is decided by ai_family.
Result: This function returns a pointer to a linked list of addrinfo structures through the return pointer argument.

return value:0--successful, non 0--error

Test results:

ai_family for IPv6, will only look for the IPv6 resolution, the general domain name is not set. Ai_family for Af_unspec, will first IPv6 IPv4, and api.mch.weixin.qq.com this domain name IPv6 parse surprisingly slow (qq.com but not slow, after the reason see).

Solution:

If the curl,c can be forced to specify IPv4, use Curl_easy_setopt (Curl, Curlopt_ipresolve, curl_ipresolve_v4);

Other languages also refer to this method.

Deep reason analysis

Nslookup-query=aaaa Api.mch.weixin.qq.com-debug is unable to find the resolution (the specified AAAA is IPv6), Then you will find an SOA statement and his superiors weixin.qq.com has a IPv6 cname, to minorshort.weixin.qq.com, and this domain name is not IPv6 parsing.

Visual IPv6 find resolution is in this SOA and CNAME place dozen circles, micro-letter students are not consider let everyone better, the domain name IPv6 settings removed.

Dig @ns-tel1.qq.com weixin.qq.com AAAA
weixin.qq.com.    43200  in  SOA ns-tel1.qq.com. webmaster.qq.com. 1293502040 300 600 86400 300

For more information on PHP related content readers can view the site topics: "PHP micro-credit Development Skills summary", "PHP coding and transcoding Operation skills Summary", "PHP Network Programming Skills Summary", "PHP basic Grammar Introductory Course", "PHP string (String) Usage Summary", "php+ MySQL Database operations Introduction tutorial and PHP Common database operation Skills Summary

I hope this article will help you with the PHP program design.