pinger-blocking.js

function pingServers(servers) {
  let failedServers = {};
  for (const url of servers) {
    let failures = 0;
    for (let i = 0 ; i < 3 ; i++) {
      const response = blockingHttpRequest(url);
      if (!response.ok) failures++;
      blockingSleep(10000);
    }
    if (failures > 0) failedServers[url] = failures;
  }
  return failedServers;
}