* fix docs and defaults

docs/configuration/index.md

@@ -855,7 +855,7 @@ These Coordinator static configurations can be defined in the `coordinator/runti
 |`druid.coordinator.load.timeout`|The timeout duration for when the Coordinator assigns a segment to a Historical process.|PT15M|
 |`druid.coordinator.kill.pendingSegments.on`|Boolean flag for whether or not the Coordinator clean up old entries in the `pendingSegments` table of metadata store. If set to true, Coordinator will check the created time of most recently complete task. If it doesn't exist, it finds the created time of the earliest running/pending/waiting tasks. Once the created time is found, then for all dataSources not in the `killPendingSegmentsSkipList` (see [Dynamic configuration](#dynamic-configuration)), Coordinator will ask the Overlord to clean up the entries 1 day or more older than the found created time in the `pendingSegments` table. This will be done periodically based on `druid.coordinator.period.indexingPeriod` specified.|true|
 |`druid.coordinator.kill.on`|Boolean flag for whether or not the Coordinator should submit kill task for unused segments, that is, permanently delete them from metadata store and deep storage. If set to true, then for all whitelisted dataSources (or optionally all), Coordinator will submit tasks periodically based on `period` specified. A whitelist can be set via dynamic configuration `killDataSourceWhitelist` described later.<br /><br />When `druid.coordinator.kill.on` is true, segments are eligible for permanent deletion once their data intervals are older than `druid.coordinator.kill.durationToRetain` relative to the current time. If a segment's data interval is older than this threshold at the time it is marked unused, it is eligible for permanent deletion immediately after being marked unused.|false|
-|`druid.coordinator.kill.period`| How often to send kill tasks to the indexing service. Value must be greater `druid.coordinator.period.indexingPeriod` if set. Only applies if kill is turned on.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | indexing period |
+|`druid.coordinator.kill.period`| The frequency of sending kill tasks to the indexing service. The value must be greater than or equal to `druid.coordinator.period.indexingPeriod`. However, if the `killUnusedSegments` duty is assigned to a custom duty group, the value must be greater than or equal to the period set for the duty group. Only applies if kill is turned on.|P1D (1 day)|
 |`druid.coordinator.kill.durationToRetain`|Only applies if you set `druid.coordinator.kill.on` to `true`. This value is ignored if `druid.coordinator.kill.ignoreDurationToRetain` is `true`. Valid configurations must be a ISO8601 period. Druid will not kill unused segments whose interval end date is beyond `now - durationToRetain`. `durationToRetain` can be a negative ISO8601 period, which would result in `now - durationToRetain` to be in the future.<br /><br />Note that the `durationToRetain` parameter applies to the segment interval, not the time that the segment was last marked unused. For example, if `durationToRetain` is set to `P90D`, then a segment for a time chunk 90 days in the past is eligible for permanent deletion immediately after being marked unused.|`P90D`|
 |`druid.coordinator.kill.ignoreDurationToRetain`|A way to override `druid.coordinator.kill.durationToRetain` and tell the coordinator that you do not care about the end date of unused segment intervals when it comes to killing them. If true, the coordinator considers all unused segments as eligible to be killed.|false|
 |`druid.coordinator.kill.bufferPeriod`|The amount of time that a segment must be unused before it is able to be permanently removed from metadata and deep storage. This can serve as a buffer period to prevent data loss if data ends up being needed after being marked unused.|`P30D`|

server/src/main/java/org/apache/druid/server/coordinator/DruidCoordinatorConfig.java

@@ -48,10 +48,8 @@ public abstract class DruidCoordinatorConfig
   public abstract Boolean getAutoKillEnabled();
 
   @Config("druid.coordinator.kill.period")
-  public Duration getCoordinatorKillPeriod()
-  {
-    return getCoordinatorIndexingPeriod();
-  }
+  @Default("P1D")
+  public abstract Duration getCoordinatorKillPeriod();
 
   @Config("druid.coordinator.kill.durationToRetain")
   @Default("P90D")

server/src/test/java/org/apache/druid/server/coordinator/DruidCoordinatorConfigTest.java

@@ -42,7 +42,7 @@ public void testDeserialization()
     Assert.assertEquals(new Duration("PT300s"), config.getCoordinatorStartDelay());
     Assert.assertEquals(new Duration("PT60s"), config.getCoordinatorPeriod());
     Assert.assertEquals(new Duration("PT1800s"), config.getCoordinatorIndexingPeriod());
-    Assert.assertEquals(new Duration("PT1800s"), config.getCoordinatorKillPeriod());
+    Assert.assertEquals(86400000, config.getCoordinatorKillPeriod().getMillis());
     Assert.assertEquals(7776000000L, config.getCoordinatorKillDurationToRetain().getMillis());
     Assert.assertEquals(100, config.getCoordinatorKillMaxSegments());
     Assert.assertEquals(new Duration(15 * 60 * 1000), config.getLoadTimeoutDelay());