Optimize Logic of Acquiring Internet IP

[317787106]

Rationale

Background

The Libp2p module used in java-tron might start slowly in some network environments, sometimes as long as ten seconds. It is necessary to boost the startup speed to optimize the user experience.

Cause Analysis

Currently, libp2p obtains the internet IP(v4) by visiting the address http://checkip.amazonaws.com, and the internet IP(v6) through https://v6.ident.me. Users from different regions around the world access this two domain may be delayed for up to ten seconds or even cannot get access at all due to some reasons. Since the acquisition of IP is in the main thread, in some cases, the startup speed is slow.

Implementation

Design

1. Several candidate domains of IPv4 & IPv6 located in different regions around the world are provided, which use concurrent requests respectively, and whichever returns first would be adopted, and other requests would be ignored.
2. If the external IP has been provided there is no need to obtain it again when P2pConfig initializes.

Solution

Three domains are provided for IPv4: "http://checkip.amazonaws.com", "https://ifconfig.me/ ", "https://4.ipw.cn/", and two domains are provided for IPv6: "https://v6.ident.me", "http://6.ipw.cn/". Then, use ExecutorCompletionService to get the result. Therefore the burden of IP acquisition is shared and faster service is offered.

The core logic is as follows:

private static String getIp(List<String> multiSrcUrls) {
    ExecutorService executor = Executors.newCachedThreadPool();
    CompletionService<String> completionService = new ExecutorCompletionService<>(executor);

    List<Callable<String>> tasks = new ArrayList<>();
    multiSrcUrls.forEach(url -> tasks.add(() -> getExternalIp(url)));

    for (Callable<String> task : tasks) {
      completionService.submit(task);
    }

    Future<String> future;
    String result = null;
    try {
      future = completionService.take();
      result = future.get();
    } catch (InterruptedException | ExecutionException e) {
      //ignore
    } finally {
      executor.shutdownNow();
    }

    return result;
  }

Testing

Time to obtain IPv4 and IPv6 addresses：

Region	hosts	Stacks	Before (ms)	Optimized (ms)
Beijing, China	testgroup022	IPv4 + IPv6	3497	486
Hong Kong, China	testgroup026-hk	IPv4	661	360
Virginia, USA	pubchain-hadoop009	IPv4	198	188
Frankfurt, Germany	depubchain-hadoop009	IPv4	293	269

[jwrct]

@317787106 Is the test data you provided a single result? What time period does it cover? If it is a single result, could you provide the average of multiple results from different time periods?

[317787106]

@317787106 Is the test data you provided a single result? What time period does it cover? If it is a single result, could you provide the average of multiple results from different time periods?

@chengtx01 what's the time period you mean? I don't have too many machines as resource limit, so I can only test it on several machines. These machines come from different time zone of the world.

[317787106]

resolve it in pr https://github.com/tronprotocol/libp2p/pull/55