diff --git a/README.md b/README.md index 3562374..a38d9fe 100644 --- a/README.md +++ b/README.md @@ -40,6 +40,46 @@ Later we can check that the nodes discover each other } ``` +Usage with Settings File +----- + +For a very simple client setup with a settings file you first need a JSON file such as: + +```json +[{ + "id":"419af818-0114-4c7b-8fdb-952915335ce4", + "port":50001, + "gossip_interval":1000, + "cleanup_interval":10000, + "members":[ + {"host":"127.0.0.1", "port":50000} + ] +}] +``` + +where: + +* `id` - is a unique id for this node (you can use any string, but above we use a UUID) +* `port` - the port to use on the default adapter on the node's machine +* `gossip_interval` - how often (in milliseconds) to gossip list of members to other node(s) +* `cleanup_interval` - when to remove 'dead' nodes (in milliseconds) +* `members` - initial seed nodes + +Then starting a local node is as simple as: + +```java +GossipService gossipService = new GossipService( + StartupSettings.fromJSONFile( "node_settings.json" ) +); +gossipService.start(); +``` + +And then when all is done, shutdown with: + +```java +gossipService.shutdown(); +``` + Event Listener ------ @@ -50,6 +90,9 @@ The status can be polled using the getters that return immutable lists. public List getDeadList() ``` +These can be accessed from the `GossipManager` on your `GossipService`, e.g: +`gossipService.get_gossipManager().getMemberList();` + Users can also attach an event listener: ```java diff --git a/src/main/java/com/google/code/gossip/GossipService.java b/src/main/java/com/google/code/gossip/GossipService.java index 728e77e..1f14cbd 100644 --- a/src/main/java/com/google/code/gossip/GossipService.java +++ b/src/main/java/com/google/code/gossip/GossipService.java @@ -29,7 +29,7 @@ public class GossipService { */ public GossipService(StartupSettings startupSettings) throws InterruptedException, UnknownHostException { - this(InetAddress.getLocalHost().getHostAddress(), startupSettings.getPort(), "", + this(InetAddress.getLocalHost().getHostAddress(), startupSettings.getPort(), startupSettings.getId(), startupSettings.getGossipMembers(), startupSettings .getGossipSettings(), null); } diff --git a/src/main/java/com/google/code/gossip/StartupSettings.java b/src/main/java/com/google/code/gossip/StartupSettings.java index a6e5d2d..7f8d5ac 100644 --- a/src/main/java/com/google/code/gossip/StartupSettings.java +++ b/src/main/java/com/google/code/gossip/StartupSettings.java @@ -8,6 +8,7 @@ import java.io.IOException; import java.util.ArrayList; import java.util.List; +import org.apache.log4j.Logger; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; @@ -18,6 +19,10 @@ import org.json.JSONObject; * @author harmenw */ public class StartupSettings { + private static final Logger log = Logger.getLogger(StartupSettings.class); + + /** The id to use fo the service */ + private String _id; /** The port to start the gossip service on. */ private int _port; @@ -31,25 +36,51 @@ public class StartupSettings { /** * Constructor. * + * @param id + * The id to be used for this service * @param port * The port to start the service on. + * @param logLevel + * unused */ - public StartupSettings(int port, int logLevel) { - this(port, new GossipSettings()); + public StartupSettings(String id, int port, int logLevel) { + this(id, port, new GossipSettings()); } /** * Constructor. * + * @param id + * The id to be used for this service * @param port * The port to start the service on. */ - public StartupSettings(int port, GossipSettings gossipSettings) { + public StartupSettings(String id, int port, GossipSettings gossipSettings) { + _id = id; _port = port; _gossipSettings = gossipSettings; _gossipMembers = new ArrayList<>(); } + /** + * Set the id to be used for this service. + * + * @param id + * The id for this service. + */ + public void setId( String id ) { + _id = id; + } + + /** + * Get the id for this service. + * + * @return the service's id. + */ + public String getId() { + return _id; + } + /** * Set the port of the gossip service. * @@ -126,6 +157,9 @@ public class StartupSettings { // Now get the port number. int port = jsonObject.getInt("port"); + // Get the id to be used + String id = jsonObject.getString("id"); + // Get the gossip_interval from the config file. int gossipInterval = jsonObject.getInt("gossip_interval"); @@ -133,22 +167,22 @@ public class StartupSettings { int cleanupInterval = jsonObject.getInt("cleanup_interval"); // Initiate the settings with the port number. - StartupSettings settings = new StartupSettings(port, new GossipSettings( + StartupSettings settings = new StartupSettings(id, port, new GossipSettings( gossipInterval, cleanupInterval)); // Now iterate over the members from the config file and add them to the settings. - System.out.print("Config-members ["); + String configMembersDetails = "Config-members ["; JSONArray membersJSON = jsonObject.getJSONArray("members"); for (int i = 0; i < membersJSON.length(); i++) { JSONObject memberJSON = membersJSON.getJSONObject(i); RemoteGossipMember member = new RemoteGossipMember(memberJSON.getString("host"), memberJSON.getInt("port"), ""); settings.addGossipMember(member); - System.out.print(member.getAddress()); + configMembersDetails += member.getAddress(); if (i < (membersJSON.length() - 1)) - System.out.print(", "); + configMembersDetails += ", "; } - System.out.println("]"); + log.info( configMembersDetails + "]" ); // Return the created settings object. return settings; diff --git a/src/test/java/io/teknek/gossip/StartupSettingsTest.java b/src/test/java/io/teknek/gossip/StartupSettingsTest.java new file mode 100644 index 0000000..7fd8487 --- /dev/null +++ b/src/test/java/io/teknek/gossip/StartupSettingsTest.java @@ -0,0 +1,79 @@ +package io.teknek.gossip; + +import com.google.code.gossip.GossipMember; +import com.google.code.gossip.GossipService; +import com.google.code.gossip.GossipSettings; +import com.google.code.gossip.StartupSettings; +import org.apache.log4j.Logger; +import org.json.JSONException; +import org.junit.Test; + +import java.io.File; +import java.io.FileOutputStream; +import java.io.IOException; +import java.util.ArrayList; +import java.util.UUID; +import java.util.concurrent.TimeUnit; + +import static org.junit.Assert.assertEquals; +import static org.junit.Assert.assertTrue; + +/** + * Tests support of using {@code StartupSettings} and thereby reading + * setup config from file. + */ +public class StartupSettingsTest { + private static final Logger log = Logger.getLogger( StartupSettingsTest.class ); + + @Test + public void testUsingSettingsFile() throws IOException, InterruptedException, JSONException { + File settingsFile = File.createTempFile("gossipTest",".json"); + log.debug( "Using settings file: " + settingsFile.getAbsolutePath() ); + settingsFile.deleteOnExit(); + writeSettingsFile(settingsFile); + + // Start the other simple node that the settings file points to + GossipService firstService = new GossipService( + "127.0.0.1", 50000, UUID.randomUUID().toString(), + new ArrayList(), new GossipSettings(), null + ); + firstService.start(); + + // Start a node with the settings file + GossipService serviceUnderTest = new GossipService( + StartupSettings.fromJSONFile( settingsFile ) + ); + serviceUnderTest.start(); + + // Let the sync up + TimeUnit.SECONDS.sleep(2); + + // Check the results + assertEquals(1, firstService.get_gossipManager().getMemberList().size() ); + assertEquals(1, serviceUnderTest.get_gossipManager().getMemberList().size() ); + assertTrue( + firstService.get_gossipManager().getMemberList().size() == + serviceUnderTest.get_gossipManager().getMemberList().size() ); + + firstService.shutdown(); + serviceUnderTest.shutdown(); + } + + private void writeSettingsFile( File target ) throws IOException { + String settings = + "[{\n" + // It is odd that this is meant to be in an array, but oh well. + " \"id\":\"" + UUID.randomUUID() + "\",\n" + + " \"port\":50001,\n" + + " \"gossip_interval\":1000,\n" + + " \"cleanup_interval\":10000,\n" + + " \"members\":[\n" + + " {\"host\":\"127.0.0.1\", \"port\":50000}\n" + + " ]\n" + + "}]"; + + log.info( "Using settings file with contents of:\n---\n" + settings + "\n---" ); + FileOutputStream output = new FileOutputStream(target); + output.write( settings.getBytes() ); + output.close(); + } +} diff --git a/src/test/java/io/teknek/gossip/TenNodeThreeSeedTest.java b/src/test/java/io/teknek/gossip/TenNodeThreeSeedTest.java index 5dcca8c..5ade6aa 100644 --- a/src/test/java/io/teknek/gossip/TenNodeThreeSeedTest.java +++ b/src/test/java/io/teknek/gossip/TenNodeThreeSeedTest.java @@ -52,11 +52,12 @@ public class TenNodeThreeSeedTest { new GossipListener(){ @Override public void gossipEvent(GossipMember member, GossipState state) { - System.out.println(member+" "+ state); + log.info(member+" "+ state); } }); clients.add(gossipService); gossipService.start(); + gossipService.get_gossipManager().getMemberList(); } TUnit.assertThat(new Callable (){ public Integer call() throws Exception {