bug4811: use only newest master when multiple exist with equal names

java/com.sap.sailing.landscape/src/com/sap/sailing/landscape/impl/SailingAnalyticsProcessImpl.java

@@ -21,6 +21,7 @@ import com.sap.sailing.landscape.SailingAnalyticsProcess;
 import com.sap.sailing.landscape.SailingAnalyticsProcessConfigurationVariable;
 import com.sap.sailing.landscape.SailingReleaseRepository;
 import com.sap.sse.common.Duration;
+import com.sap.sse.common.TimePoint;
 import com.sap.sse.landscape.Host;
 import com.sap.sse.landscape.Release;
 import com.sap.sse.landscape.ReleaseRepository;
@@ -102,9 +103,14 @@ implements SailingAnalyticsProcess<ShardingKey> {
 
     @Override
     public Release getVersion(Optional<Duration> optionalTimeout, Optional<String> optionalKeyName, byte[] privateKeyEncryptionPassphrase) throws Exception {
-        // TODO see getRelease TODO note... we should try to obtain this from the REST API /gwt/status where we need to spread the buildversion info across fine-grained attributes
         return getRelease(SailingReleaseRepository.INSTANCE, optionalTimeout, optionalKeyName, privateKeyEncryptionPassphrase);
     }
+    
+    @Override
+    public TimePoint getStartTimePoint(Optional<Duration> optionalTimeout) throws IOException, ParseException {
+        final JSONObject status = getStatus(optionalTimeout);
+        return TimePoint.of(((Number) status.get("start_time_millis")).longValue());
+    }
 
     @Override
     public int getExpeditionUdpPort(Optional<Duration> optionalTimeout, Optional<String> optionalKeyName, byte[] privateKeyEncryptionPassphrase)

java/com.sap.sse.landscape.aws/src/com/sap/sse/landscape/aws/AwsLandscape.java

@@ -552,7 +552,10 @@ public interface AwsLandscape<ShardingKey> extends Landscape<ShardingKey> {
      * specified by {@code tagName} and discovers all application server processes configured on it. These are then
      * grouped by {@link ApplicationProcess#getServerName(Optional, Optional, byte[]) server name}, and using
      * {@link ApplicationProcess#getMasterServerName(Optional)} the master/replica relationships between the processes with equal server
-     * name are discovered. From this, an {@link ApplicationReplicaSet} is established per server name.
+     * name are discovered. From this, an {@link ApplicationReplicaSet} is established per server name.<p>
+     * 
+     * Should more than one master exist with equal server name, only the newest master is considered.
+     * 
      * @param optionalTimeout
      *            an optional timeout for communicating with the application server(s) to try to read the application
      *            configuration; used, e.g., as timeout during establishing SSH connections

java/com.sap.sse.landscape.aws/src/com/sap/sse/landscape/aws/impl/AwsLandscapeImpl.java

@@ -1094,7 +1094,11 @@ public class AwsLandscapeImpl<ShardingKey> implements AwsLandscape<ShardingKey>
                     // then applicationProcess is a replica in the serverName cluster:
                     Util.addToValueSet(replicasByServerName, serverName, applicationProcess);
                 } else {
-                    mastersByServerName.put(serverName, applicationProcess);
+                    // check if it's a new or else a newer master:
+                    if (!mastersByServerName.containsKey(serverName)
+                    || mastersByServerName.get(serverName).getStartTimePoint(optionalTimeout).before(applicationProcess.getStartTimePoint(optionalTimeout))) {
+                        mastersByServerName.put(serverName, applicationProcess);
+                    }
                 }
             }
         }

java/com.sap.sse.landscape/src/com/sap/sse/landscape/application/ApplicationProcess.java

@@ -9,8 +9,11 @@ import java.util.concurrent.TimeoutException;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+import org.json.simple.parser.ParseException;
+
 import com.jcraft.jsch.ChannelSftp;
 import com.sap.sse.common.Duration;
+import com.sap.sse.common.TimePoint;
 import com.sap.sse.landscape.AvailabilityZone;
 import com.sap.sse.landscape.Host;
 import com.sap.sse.landscape.Landscape;
@@ -138,4 +141,6 @@ extends Process<RotatingFileBasedLog, MetricsT> {
     }
 
     Release getVersion(Optional<Duration> optionalTimeout, Optional<String> optionalKeyName, byte[] privateKeyEncryptionPassphrase) throws Exception;
+
+    TimePoint getStartTimePoint(Optional<Duration> optionalTimeout) throws IOException, ParseException;
 }

java/com.sap.sse.landscape/src/com/sap/sse/landscape/application/ProcessFactory.java

@@ -6,6 +6,12 @@ import com.sap.sse.landscape.Host;
 
 @FunctionalInterface
 public interface ProcessFactory<ShardingKey, MetricsT extends ApplicationProcessMetrics, ProcessT extends ApplicationProcess<ShardingKey, MetricsT, ProcessT>, HostT extends Host> {
+    /**
+     * @param additionalProperties
+     *            can be used to pass through values required for calling the {@link ApplicationProcess} subclass
+     *            constructor which may require more arguments than the ones that appear as fixed arguments
+     *            on this method.
+     */
     ProcessT createProcess(HostT host, int port, String serverDirectory, int telnetPort, String serverName,
             Map<String, Object> additionalProperties);
 }