Use parameters instead of random

Author: thecoop

docs/changelog/135778.yaml

@@ -1,5 +1,5 @@
 pr: 135778
-summary: Add on-disk rescoring to disk BBQ
+summary: "Add `on_disk_rescore: true` option to disk BBQ to rescore vectors on-disk without loading into memory"
 area: Vector Search
 type: feature
 issues: []

server/src/internalClusterTest/java/org/elasticsearch/index/store/DirectIOIT.java

@@ -9,6 +9,8 @@
 
 package org.elasticsearch.index.store;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.logging.log4j.Level;
 import org.apache.lucene.misc.store.DirectIODirectory;
 import org.apache.lucene.store.Directory;
@@ -67,14 +69,24 @@ protected boolean useDirectIO(String name, IOContext context, OptionalLong fileL
         };
     }
 
+    private final String type;
+
+    @ParametersFactory
+    public static Iterable<Object[]> parameters() {
+        return List.<Object[]>of(new Object[] { "bbq_disk" });
+    }
+
+    public DirectIOIT(String type) {
+        this.type = type;
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return List.of(InternalSettingsPlugin.class);
     }
 
     private String indexVectors(boolean directIO) {
         String indexName = "test-vectors-" + directIO;
-        String type = randomFrom("bbq_disk");
         assertAcked(
             prepareCreate(indexName).setSettings(Settings.builder().put(InternalSettingsPlugin.USE_COMPOUND_FILE.getKey(), false))
                 .setMapping(Strings.format("""