Add start_time column to sys.servers

docs/querying/sql-metadata-tables.md

@@ -208,7 +208,7 @@ Servers table lists all discovered servers in the cluster.
 |current_size|BIGINT|Current size of segments in bytes on this server. Only valid for HISTORICAL type, for other types it's 0|
 |max_size|BIGINT|Max size in bytes this server recommends to assign to segments see [druid.server.maxSize](../configuration/index.md#historical-general-configuration). Only valid for HISTORICAL type, for other types it's 0|
 |is_leader|BIGINT|1 if the server is currently the 'leader' (for services which have the concept of leadership), otherwise 0 if the server is not the leader, or the default long value (0 or null depending on `druid.generic.useDefaultValueForNull`) if the server type does not have the concept of leadership|
-
+|start_time|STRING|Timestamp in ISO8601 format when the server was announced in the cluster|
 To retrieve information about all servers, use the query:
 
 ```sql

integration-tests/src/test/java/org/apache/druid/tests/security/AbstractAuthConfigurationTest.java

@@ -276,7 +276,7 @@ public void test_systemSchemaAccess_admin() throws Exception
     verifySystemSchemaServerQuery(
         adminClient,
         SYS_SCHEMA_SERVERS_QUERY,
-        getServersWithoutCurrentSize(adminServers)
+        getServersWithoutCurrentSizeAndStartTime(adminServers)
     );
 
     LOG.info("Checking sys.server_segments query as admin...");
@@ -767,7 +767,7 @@ protected void verifySystemSchemaQueryBase(
     String content = responseHolder.getContent();
     List<Map<String, Object>> responseMap = jsonMapper.readValue(content, SYS_SCHEMA_RESULTS_TYPE_REFERENCE);
     if (isServerQuery) {
-      responseMap = getServersWithoutCurrentSize(responseMap);
+      responseMap = getServersWithoutCurrentSizeAndStartTime(responseMap);
     }
     Assert.assertEquals(responseMap, expectedResults);
   }
@@ -914,7 +914,7 @@ protected void setExpectedSystemSchemaObjects() throws IOException
         SYS_SCHEMA_RESULTS_TYPE_REFERENCE
     );
 
-    adminServers = getServersWithoutCurrentSize(
+    adminServers = getServersWithoutCurrentSizeAndStartTime(
         jsonMapper.readValue(
             fillServersTemplate(
                 config,
@@ -937,13 +937,14 @@ protected void setExpectedSystemSchemaObjects() throws IOException
    * curr_size on historicals changes because cluster state is not isolated across different
    * integration tests, zero it out for consistent test results
    */
-  protected static List<Map<String, Object>> getServersWithoutCurrentSize(List<Map<String, Object>> servers)
+  protected static List<Map<String, Object>> getServersWithoutCurrentSizeAndStartTime(List<Map<String, Object>> servers)
   {
     return Lists.transform(
         servers,
         (server) -> {
           Map<String, Object> newServer = new HashMap<>(server);
           newServer.put("curr_size", 0);
+          newServer.put("start_time", "0");
           return newServer;
         }
     );

integration-tests/src/test/resources/results/auth_test_sys_schema_servers.json

@@ -8,7 +8,8 @@
     "tier": "_default_tier",
     "curr_size": 2208932412,
     "max_size": 5000000000,
-    "is_leader": %%NON_LEADER%%
+    "is_leader": %%NON_LEADER%%,
+    "start_time": "0"
   },
   {
     "server": "%%BROKER%%:8282",
@@ -19,6 +20,7 @@
     "tier": "_default_tier",
     "curr_size": 0,
     "max_size": 1000000000,
-    "is_leader": %%NON_LEADER%%
+    "is_leader": %%NON_LEADER%%,
+    "start_time": "0"
   }
 ]

server/src/main/java/org/apache/druid/discovery/DiscoveryDruidNode.java

@@ -26,10 +26,12 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.collect.Maps;
 import org.apache.druid.jackson.StringObjectPairList;
+import org.apache.druid.java.util.common.DateTimes;
 import org.apache.druid.java.util.common.IAE;
 import org.apache.druid.java.util.common.NonnullPair;
 import org.apache.druid.java.util.common.logger.Logger;
 import org.apache.druid.server.DruidNode;
+import org.joda.time.DateTime;
 
 import javax.annotation.Nullable;
 import java.util.HashMap;
@@ -50,6 +52,7 @@ public class DiscoveryDruidNode
 
   private final DruidNode druidNode;
   private final NodeRole nodeRole;
+  private final DateTime startTime;
 
   /**
    * Map of service name -> DruidServices.
@@ -66,20 +69,32 @@ public DiscoveryDruidNode(
       NodeRole nodeRole,
       Map<String, DruidService> services
   )
+  {
+    this(druidNode, nodeRole, services, DateTimes.nowUtc());
+  }
+
+  public DiscoveryDruidNode(
+      DruidNode druidNode,
+      NodeRole nodeRole,
+      Map<String, DruidService> services,
+      DateTime startTime
+  )
   {
     this.druidNode = druidNode;
     this.nodeRole = nodeRole;
 
     if (services != null && !services.isEmpty()) {
       this.services.putAll(services);
     }
+    this.startTime = startTime;
   }
 
   @JsonCreator
   private static DiscoveryDruidNode fromJson(
       @JsonProperty("druidNode") DruidNode druidNode,
       @JsonProperty("nodeType") NodeRole nodeRole,
       @JsonProperty("services") Map<String, StringObjectPairList> rawServices,
+      @JsonProperty("startTime") DateTime startTime,
       @JacksonInject ObjectMapper jsonMapper
   )
   {
@@ -95,7 +110,7 @@ private static DiscoveryDruidNode fromJson(
         }
       }
     }
-    return new DiscoveryDruidNode(druidNode, nodeRole, services);
+    return new DiscoveryDruidNode(druidNode, nodeRole, services, startTime);
   }
 
   /**
@@ -106,10 +121,10 @@ private static DiscoveryDruidNode fromJson(
    * This is definitely a bug of DataNodeService, but, since renaming one of those duplicate keys will
    * break compatibility, DataNodeService still has the deprecated "type" property.
    * See the Javadoc of DataNodeService for more details.
-   *
+   * <p>
    * This function catches such duplicate keys and rewrites the deprecated "type" to "serverType",
    * so that we don't lose any properties.
-   *
+   * <p>
    * This method can be removed together when we entirely remove the deprecated "type" property from DataNodeService.
    */
   @Deprecated
@@ -166,6 +181,12 @@ public DruidNode getDruidNode()
     return druidNode;
   }
 
+  @JsonProperty
+  public DateTime getStartTime()
+  {
+    return startTime;
+  }
+
   @Nullable
   @JsonIgnore
   public <T extends DruidService> T getService(String key, Class<T> clazz)
@@ -205,7 +226,8 @@ public String toString()
     return "DiscoveryDruidNode{" +
            "druidNode=" + druidNode +
            ", nodeRole='" + nodeRole + '\'' +
-           ", services=" + services +
+           ", services=" + services + '\'' +
+           ", startTime=" + startTime +
            '}';
   }
 }

server/src/test/java/org/apache/druid/discovery/DiscoveryDruidNodeTest.java

@@ -59,6 +59,7 @@ public void testEquals()
   {
     EqualsVerifier.forClass(DiscoveryDruidNode.class)
                   .withNonnullFields("druidNode", "nodeRole", "services")
+                  .withIgnoredFields("startTime")
                   .usingGetClass()
                   .verify();
   }

services/src/main/java/org/apache/druid/cli/CliOverlord.java

@@ -267,13 +267,13 @@ public void configure(Binder binder)
 
             if (standalone) {
               LifecycleModule.register(binder, Server.class);
-            }
 
-            bindAnnouncer(
-                binder,
-                IndexingService.class,
-                DiscoverySideEffectsProvider.create()
-            );
+              bindAnnouncer(
+                  binder,
+                  IndexingService.class,
+                  DiscoverySideEffectsProvider.create()
+              );
+            }
 
             Jerseys.addResource(binder, SelfDiscoveryResource.class);
             LifecycleModule.registerKey(binder, Key.get(SelfDiscoveryResource.class));

sql/src/main/java/org/apache/druid/sql/calcite/schema/SystemSchema.java

@@ -163,6 +163,7 @@ public class SystemSchema extends AbstractSchema
       .add("curr_size", ColumnType.LONG)
       .add("max_size", ColumnType.LONG)
       .add("is_leader", ColumnType.LONG)
+      .add("start_time", ColumnType.STRING)
       .build();
 
   static final RowSignature SERVER_SEGMENTS_SIGNATURE = RowSignature
@@ -595,7 +596,8 @@ private static Object[] buildRowForNonDataServer(DiscoveryDruidNode discoveryDru
           null,
           UNKNOWN_SIZE,
           UNKNOWN_SIZE,
-          NullHandling.defaultLongValue()
+          NullHandling.defaultLongValue(),
+          toStringOrNull(discoveryDruidNode.getStartTime())
       };
     }
 
@@ -614,7 +616,8 @@ private static Object[] buildRowForNonDataServerWithLeadership(DiscoveryDruidNod
           null,
           UNKNOWN_SIZE,
           UNKNOWN_SIZE,
-          isLeader ? 1L : 0L
+          isLeader ? 1L : 0L,
+          toStringOrNull(discoveryDruidNode.getStartTime())
       };
     }
 
@@ -648,7 +651,8 @@ private static Object[] buildRowForDiscoverableDataServer(
           druidServerToUse.getTier(),
           currentSize,
           druidServerToUse.getMaxSize(),
-          NullHandling.defaultLongValue()
+          NullHandling.defaultLongValue(),
+          toStringOrNull(discoveryDruidNode.getStartTime())
       };
     }