short_programming_guide_for_smart_subdomains [GeoScaling Documentation/Manual]

--- short_programming_guide_for_smart_subdomains 2015/01/24 21:38
+++ short_programming_guide_for_smart_subdomains 2015/01/30 00:41 current
@@ Line 31: / Line 31: @@
 All country names are **lower-case**. You can find a list of possible countries, including codes for Satellite Providers and Anonymous Proxies, [[http://www.maxmind.com/app/iso3166|here]].
+**Please note**: You need to select "Share country name" in the smart subdomains form for the country information to be available to the script!
 === Return serveral IPs ===
@@ Line 75: / Line 77: @@
 GeoScaling DNS2 can redirect based on the AS number of the network the visitor comes from.
-If it is defined, the $as variable contains an **array** of **lower case** possible network names. The array usually contains only one element. You can make a simple redirect:
+If it is defined, the $as variable contains the AS/ASN network id in **lower case**. You can make a simple redirect:
 <code php>
-if( in_array("as30890", $as) )
+if( $as == "as6128" )
   $output[] = array("A", "127.0.0.1");
 else
@@ Line 87: / Line 89: @@
 <code php>
-if( sizeof( array_intersect ( $as, array("as30890", "as24745") ) ) )
+if( in_array ( $as, array("as30890", "as24745", "as6128") ) )
   $output[] = array("A", "127.0.0.1");
 else
   $output[] = array("A", "127.0.0.2");
 </code>
+**Please note**: You need to select "Share network name / AS number" in the smart subdomains form for the network information to be available to the script!
 === Redirecting on uptime information ===
@@ Line 116: / Line 120: @@
   $output[] = array("A", "96.9.130.197"); // backup mirror
 </code>
+**Please note**: You need to select "Share uptime info" in the smart subdomains form for the uptime information to be available to the script!
 === Redirecting based on extra information ===
@@ Line 143: / Line 149: @@
 $payload['datacenter3'] = "87";
 </code>
+**Please note**: You need to select "Share extra info (like server load)" in the smart subdomains form for the extra information to be available to the script!
 === Other useful variables sent to the script ===
@@ Line 179: / Line 187: @@
 {
   $output[] = array("A", "91.121.158.100", "400"); // return IP 91.121.158.100 with a TTL of 400
+}
+</code>
+=== Return the closest server to the user ===
+<code php>
+$new_server['lat'] = 41.0186111;
+$new_server['lon'] = 28.9647222;
+$new_server['loc'] = "Istanbul TR";
+$new_server['ip'] = "1.2.3.4"; // IP1
+$servers[] = $new_server;
+$new_server['lat'] = 47.6063889;
+$new_server['lon'] = -122.3308333;
+$new_server['loc'] = "Seattle, Wa";
+$new_server['ip'] = "1.2.3.5"; // IP2
+$servers[] = $new_server;
+$new_server['lat'] = 32.7833333;
+$new_server['lon'] = -96.8;
+$new_server['loc'] = "Dallas, TX";
+$new_server['ip'] = "1.2.3.6"; // IP3
+$servers[] = $new_server;
+$new_server['lat'] = 38.895;
+$new_server['lon'] = -77.0366667;
+$new_server['loc'] = "Washington D.C.";
+$new_server['ip'] = "1.2.3.7"; // IP4
+$servers[] = $new_server;
+$current_lat = $city_info['latitude'];
+$current_lon = $city_info['longitude'];
+$minimum_distance = PHP_INT_MAX;
+$minimum_distance_server_id = 0;
+for($i=0 ; $i<sizeof($servers); $i++)
+{
+    $server = $servers[$i];
+    $distance_to_user = @distance($current_lat, $current_lon, $server['lat'], $server['lon'], "k");
+    if($distance_to_user<$minimum_distance)
+    {
+	$minimum_distance = $distance_to_user;
+	$minimum_distance_server_id = $i;
+    }
+}
+$output[] = array("A", $servers[$minimum_distance_server_id]['ip']);
+/*::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
+/*::                                                                         :*/
+/*::  this routine calculates the distance between two points (given the     :*/
+/*::  latitude/longitude of those points). it is being used to calculate     :*/
+/*::  the distance between two zip codes or postal codes using our           :*/
+/*::  zipcodeworld(tm) and postalcodeworld(tm) products.                     :*/
+/*::                                                                         :*/
+/*::  definitions:                                                           :*/
+/*::    south latitudes are negative, east longitudes are positive           :*/
+/*::                                                                         :*/
+/*::  passed to function:                                                    :*/
+/*::    lat1, lon1 = latitude and longitude of point 1 (in decimal degrees)  :*/
+/*::    lat2, lon2 = latitude and longitude of point 2 (in decimal degrees)  :*/
+/*::    unit = the unit you desire for results                               :*/
+/*::           where: 'm' is statute miles                                   :*/
+/*::                  'k' is kilometers (default)                            :*/
+/*::                  'n' is nautical miles                                  :*/
+/*::  united states zip code/ canadian postal code databases with latitude & :*/
+/*::  longitude are available at http://www.zipcodeworld.com                 :*/
+/*::                                                                         :*/
+/*::  For enquiries, please contact sales@zipcodeworld.com                   :*/
+/*::                                                                         :*/
+/*::  official web site: http://www.zipcodeworld.com                         :*/
+/*::                                                                         :*/
+/*::  hexa software development center © all rights reserved 2004            :*/
+/*::                                                                         :*/
+/*::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
+//echo distance(32.9697, -96.80322, 29.46786, -98.53506, "m") . " miles<br>";
+//echo distance(32.9697, -96.80322, 29.46786, -98.53506, "k") . " kilometers<br>";
+//echo distance(32.9697, -96.80322, 29.46786, -98.53506, "n") . " nautical miles<br>";
+function distance($lat1, $lon1, $lat2, $lon2, $unit)
+{
+  $theta = $lon1 - $lon2;
+  $dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) +  cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));
+  $dist = acos($dist);
+  $dist = rad2deg($dist);
+  $miles = $dist * 60 * 1.1515;
+  $unit = strtoupper($unit);
+  if ($unit == "K") {
+    return ($miles * 1.609344);
+  } else if ($unit == "N") {
+      return ($miles * 0.8684);
+    } else {
+        return $miles;
+      }
+}
+</code>
+=== Output debug information in TXT records ===
+This simple script generates TXT records with the information GeoScaling sends to your script:
+<code php>
+$output[] = array("TXT", "City Info: ".var_export($city_info, true));
+$output[] = array("TXT", "Network info: ".var_export($as, true));
+$output[] = array("TXT", "Country: ".$country);
+$output[] = array("TXT", "Subdomain: ".$subdomain);
+$output[] = array("TXT", "Remote IP: ".$remote_ip);</code>
+Now, if you make a DNS request for the TXT records of your subdomain:
+<code>
+dig -t TXT geo.nyuu.org @ns1.geoscaling.com
+</code>
+you will get something like this:
+<code>
+...
+;; ANSWER SECTION:
+geo.nyuu.org.		300	IN	TXT	"Remote IP: 67.82.29.100"
+geo.nyuu.org.		300	IN	TXT	"Network info: 'as6128'"
+geo.nyuu.org.		300	IN	TXT	"City Info: array (   'city' => 'newark',   'country' => 'us',   'region' => 'nj',   'latitude' => 40.734,   'longitude' => -74.1868, )"
+geo.nyuu.org.		300	IN	TXT	"Country: us"
+geo.nyuu.org.		300	IN	TXT	"Subdomain: geo.nyuu.org"
+...
+</code>
+User contribution that combines, Closest, plus uptime / take server offline, plus send extra info to take server offline during a deployment
+See send extra_info wiki part, to see the php code that sends the associated extra_info via a URL
+<code php>
+/*
+GeoScaling "smart subdomain script"
+        PURPOSE:
+/ associate url/IP with the physically closest server, monitoring with www.monitis.com reveals minimum of 2x improvement in latency if we do this
+/ take a server out of the list of possible servers if GeoScaling monitoring shows it as down
+/ take a sever out of the list (immediate effect) if we are about to deploy an upgrade of the app software by sending "extra_info"
+        Contributed BY: keitht@sasimedia.net
+        AVAILABLE INFRASTRUCTURE CONSULTING ON
+/ automated build and deploy the N servers in the cloud
+/ Unix or Windows cloud server setup (linode / Rackspace / other)
+/ Techniques for achieving fastest initial page load
+/ No SQL keystore for database replication across cloud servers (Hazelcast + Voldemort + Oracle BDB)
+/ HA / 100 % uptime
+/ Smart browser clients (Flex / GWT), with service calls automatically tied to the fastest responding server (not necessarily the closest)
+*/
+$info = unserialize($extra_info);
+if($uptime['Linode-s1.info']==1 && strcmp($info['linode-s1-offline'],'true') != 0){
+$new_server['lat'] = 37.4919627;
+$new_server['lon'] = -121.93811;
+$new_server['loc'] = "Fremont, California";
+$new_server['ip'] = "1.1.1.1"; //linode-s1 CA
+$servers[] = $new_server;
+}
+if($uptime['rackspace-s1.info']==1 && strcmp($info['rackspace-s1-offline'],'true') != 0){
+$new_server['lat'] = 32.7833333;
+$new_server['lon'] = -96.8;
+$new_server['loc'] = "Dallas, TX";
+$new_server['ip'] = "1.1.1.1"; //rackspace-s1 DALLAS
+$servers[] = $new_server;
+}
+if($uptime['rackspace-s1.info']==1 && strcmp($info['rackspace-s2-offline'],'true') != 0){
+$new_server['lat'] = 41.85;
+$new_server['lon'] = -87.65;
+$new_server['loc'] = "Chicago, IL";
+$new_server['ip'] = "1.1.1.1";  // rackspace-s2 CHICAGO
+$servers[] = $new_server;
+}
+if($uptime['Linode-s2.info']==1 && strcmp($info['linode-s2-offline'],'true') != 0){
+$new_server['lat'] = 33.73;
+$new_server['lon'] = -84.38;
+$new_server['loc'] = "Atlanta, GA.";
+$new_server['ip'] = "11.1.1.1";  // linode-s2 ATLANTA
+$servers[] = $new_server;
+}
+$current_lat = $city_info['latitude'];
+$current_lon = $city_info['longitude'];
+$minimum_distance = PHP_INT_MAX;
+$minimum_distance_server_id = 0;
+for($i=0 ; $i<sizeof($servers); $i++)
+{
+    $server = $servers[$i];
+    $distance_to_user = @distance($current_lat, $current_lon, $server['lat'], $server['lon'], "k");
+    if($distance_to_user<$minimum_distance)
+    {
+	$minimum_distance = $distance_to_user;
+	$minimum_distance_server_id = $i;
+    }
+}
+$output[] = array("A", $servers[$minimum_distance_server_id]['ip']);
+/*::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
+/*::                                                                         :*/
+/*::  this routine calculates the distance between two points (given the     :*/
+/*::  latitude/longitude of those points). it is being used to calculate     :*/
+/*::  the distance between two zip codes or postal codes using our           :*/
+/*::  zipcodeworld(tm) and postalcodeworld(tm) products.                     :*/
+/*::                                                                         :*/
+/*::  definitions:                                                           :*/
+/*::    south latitudes are negative, east longitudes are positive           :*/
+/*::                                                                         :*/
+/*::  passed to function:                                                    :*/
+/*::    lat1, lon1 = latitude and longitude of point 1 (in decimal degrees)  :*/
+/*::    lat2, lon2 = latitude and longitude of point 2 (in decimal degrees)  :*/
+/*::    unit = the unit you desire for results                               :*/
+/*::           where: 'm' is statute miles                                   :*/
+/*::                  'k' is kilometers (default)                            :*/
+/*::                  'n' is nautical miles                                  :*/
+/*::  united states zip code/ canadian postal code databases with latitude & :*/
+/*::  longitude are available at http://www.zipcodeworld.com                 :*/
+/*::                                                                         :*/
+/*::  For enquiries, please contact sales@zipcodeworld.com                   :*/
+/*::                                                                         :*/
+/*::  official web site: http://www.zipcodeworld.com                         :*/
+/*::                                                                         :*/
+/*::  hexa software development center © all rights reserved 2004            :*/
+/*::                                                                         :*/
+/*::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
+//echo distance(32.9697, -96.80322, 29.46786, -98.53506, "m") . " miles<br>";
+//echo distance(32.9697, -96.80322, 29.46786, -98.53506, "k") . " kilometers<br>";
+//echo distance(32.9697, -96.80322, 29.46786, -98.53506, "n") . " nautical miles<br>";
+function distance($lat1, $lon1, $lat2, $lon2, $unit)
+{
+  $theta = $lon1 - $lon2;
+  $dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) +  cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));
+  $dist = acos($dist);
+  $dist = rad2deg($dist);
+  $miles = $dist * 60 * 1.1515;
+  $unit = strtoupper($unit);
+  if ($unit == "K") {
+    return ($miles * 1.609344);
+  } else if ($unit == "N") {
+      return ($miles * 0.8684);
+    } else {
+        return $miles;
+      }
 }
 </code>