javadocs

Author: ywelsch

server/src/main/java/org/elasticsearch/discovery/zen/SettingsBasedHostsProvider.java

@@ -30,11 +30,18 @@
 
 import static java.util.Collections.emptyList;
 
+/**
+ * An implementation of {@link UnicastHostsProvider} that reads hosts/ports
+ * from the "discovery.zen.ping.unicast.hosts" node setting. If the port is
+ * left off an entry, a default port of 9300 is assumed.
+ *
+ * An example unicast hosts setting might look as follows:
+ * [67.81.244.10, 67.81.244.11:9305, 67.81.244.15:9400]
+ */
 public class SettingsBasedHostsProvider extends AbstractComponent implements UnicastHostsProvider {
 
     public static final Setting<List<String>> DISCOVERY_ZEN_PING_UNICAST_HOSTS_SETTING =
-        Setting.listSetting("discovery.zen.ping.unicast.hosts", emptyList(), Function.identity(),
-            Setting.Property.NodeScope);
+        Setting.listSetting("discovery.zen.ping.unicast.hosts", emptyList(), Function.identity(), Setting.Property.NodeScope);
 
     // these limits are per-address
     public static final int LIMIT_FOREIGN_PORTS_COUNT = 1;
@@ -49,7 +56,7 @@ public SettingsBasedHostsProvider(Settings settings, TransportService transportS
 
         if (DISCOVERY_ZEN_PING_UNICAST_HOSTS_SETTING.exists(settings)) {
             configuredHosts = DISCOVERY_ZEN_PING_UNICAST_HOSTS_SETTING.get(settings);
-            // we only limit to 1 addresses, makes no sense to ping 100 ports
+            // we only limit to 1 address, makes no sense to ping 100 ports
             limitPortCounts = LIMIT_FOREIGN_PORTS_COUNT;
         } else {
             // if unicast hosts are not specified, fill with simple defaults on the local machine

server/src/main/java/org/elasticsearch/discovery/zen/UnicastHostsProvider.java

@@ -33,6 +33,11 @@ public interface UnicastHostsProvider {
      */
     List<TransportAddress> buildDynamicHosts(HostsResolver hostsResolver);
 
+    /**
+     * Helper object that allows to resolve a list of hosts to a list of transport addresses.
+     * Each host is resolved into a transport address (or a collection of addresses if the
+     * number of ports is greater than one)
+     */
     interface HostsResolver {
         List<TransportAddress> resolveHosts(List<String> hosts, int limitPortCounts);
     }

server/src/main/java/org/elasticsearch/discovery/zen/UnicastZenPing.java

@@ -150,9 +150,9 @@ public UnicastZenPing(Settings settings, ThreadPool threadPool, TransportService
     }
 
     /**
-     * Resolves a list of hosts to a list of discovery nodes. Each host is resolved into a transport address (or a collection of addresses
-     * if the number of ports is greater than one) and the transport addresses are used to created discovery nodes. Host lookups are done
-     * in parallel using specified executor service up to the specified resolve timeout.
+     * Resolves a list of hosts to a list of transport addresses. Each host is resolved into a transport address (or a collection of
+     * addresses if the number of ports is greater than one). Host lookups are done in parallel using specified executor service up
+     * to the specified resolve timeout.
      *
      * @param executorService  the executor service used to parallelize hostname lookups
      * @param logger           logger used for logging messages regarding hostname lookups