Remove cluster setting validator for default rollover (#94447)

Author: gmarouli

docs/changelog/94447.yaml

@@ -0,0 +1,5 @@
+pr: 94447
+summary: Remove rollover cluster setting validator
+area: DLM
+type: bug
+issues: []

server/src/main/java/org/elasticsearch/cluster/metadata/DataLifecycle.java

@@ -26,8 +26,6 @@
 import org.elasticsearch.xcontent.XContentParser;
 
 import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
 import java.util.Objects;
 
 /**
@@ -39,32 +37,10 @@ public class DataLifecycle implements SimpleDiffable<DataLifecycle>, ToXContentO
         "cluster.dlm.default.rollover",
         "max_age=7d,max_primary_shard_size=50gb,min_docs=1,max_primary_shard_docs=200000000",
         (s) -> RolloverConditions.parseSetting(s, "cluster.dlm.default.rollover"),
-        new RolloverConditionsValidator(),
         Setting.Property.Dynamic,
         Setting.Property.NodeScope
     );
 
-    /**
-     * We require the default rollover conditions to have min_docs set to a non-negative number to avoid empty indices
-     * and to have at least one MAX condition set to ensure that the rollover will be triggered.
-     */
-    static class RolloverConditionsValidator implements Setting.Validator<RolloverConditions> {
-
-        @Override
-        public void validate(RolloverConditions value) {
-            List<String> errors = new ArrayList<>(2);
-            if (value.getMinDocs() == null && value.getMinPrimaryShardDocs() == null) {
-                errors.add("Either min_docs or min_primary_shard_docs rollover conditions should be set and greater than 0.");
-            }
-            if (value.hasMaxConditions() == false) {
-                errors.add("At least one max_* rollover condition must be set.");
-            }
-            if (errors.isEmpty() == false) {
-                throw new IllegalArgumentException(String.join(" ", errors));
-            }
-        }
-    }
-
     private static final FeatureFlag DLM_FEATURE_FLAG = new FeatureFlag("dlm");
 
     public static final DataLifecycle EMPTY = new DataLifecycle();

server/src/test/java/org/elasticsearch/cluster/metadata/DataLifecycleTests.java

@@ -97,14 +97,5 @@ public void testInvalidClusterSetting() {
             );
             assertThat(exception.getMessage(), equalTo("The rollover conditions cannot be null or blank"));
         }
-        {
-            IllegalArgumentException exception = expectThrows(
-                IllegalArgumentException.class,
-                () -> DataLifecycle.CLUSTER_DLM_DEFAULT_ROLLOVER_SETTING.get(
-                    Settings.builder().put(DataLifecycle.CLUSTER_DLM_DEFAULT_ROLLOVER_SETTING.getKey(), "min_docs=1").build()
-                )
-            );
-            assertThat(exception.getMessage(), equalTo("At least one max_* rollover condition must be set."));
-        }
     }
 }