TSDB: Fix RollupActionSingleNodeTests failing with IndexNotFoundException (#87333)

Looks like the failure reported at #69799 (comment) happens because of
randomly generated index names conflict between two tests.

    Add more random numbers to test names, so that the probability of conflicts is negligible
    Generate source and rollup index names more carefully so that they are logged properly.
    Cleanup test code

Fixes #69799

Author: csoulios

x-pack/plugin/rollup/src/test/java/org/elasticsearch/xpack/rollup/v2/RollupActionSingleNodeTests.java

@@ -94,7 +94,7 @@ public class RollupActionSingleNodeTests extends ESSingleNodeTestCase {
     private static final int MAX_DIM_VALUES = 5;
     private static final long MAX_NUM_BUCKETS = 10;
 
-    private String sourceIndex, sourceIndexClone, rollupIndex;
+    private String sourceIndex, rollupIndex;
     private long startTime;
     private int docCount, numOfShards, numOfReplicas;
     private List<String> dimensionValues;
@@ -112,13 +112,12 @@ protected Collection<Class<? extends Plugin>> getPlugins() {
 
     @Before
     public void setup() {
-        sourceIndex = randomAlphaOfLength(5).toLowerCase(Locale.ROOT);
-        sourceIndexClone = sourceIndex + "-clone";
-        rollupIndex = randomAlphaOfLength(6).toLowerCase(Locale.ROOT);
+        sourceIndex = getTestName().toLowerCase(Locale.ROOT) + "-" + randomAlphaOfLength(4).toLowerCase(Locale.ROOT);
+        rollupIndex = "rollup-" + sourceIndex;
         startTime = randomLongBetween(946769284000L, 1607470084000L); // random date between 2000-2020
         docCount = randomIntBetween(10, 9000);
         numOfShards = randomIntBetween(1, 4);
-        numOfReplicas = randomIntBetween(0, 3);
+        numOfReplicas = 0; // Since this is a single node, we cannot have replicas
 
         // Values for keyword dimensions
         dimensionValues = new ArrayList<>(MAX_DIM_VALUES);
@@ -169,6 +168,8 @@ public void testRollupIndex() throws IOException {
         };
         bulkIndex(sourceSupplier);
         prepareSourceIndex(sourceIndex);
+        // Clone the source index before rollup deletes it
+        String sourceIndexClone = cloneSourceIndex(sourceIndex);
         rollup(sourceIndex, rollupIndex, config);
         assertRollupIndex(config, sourceIndex, sourceIndexClone, rollupIndex);
     }
@@ -217,6 +218,8 @@ public void testRollupSparseMetrics() throws IOException {
         };
         bulkIndex(sourceSupplier);
         prepareSourceIndex(sourceIndex);
+        // Clone the source index before rollup deletes it
+        String sourceIndexClone = cloneSourceIndex(sourceIndex);
         rollup(sourceIndex, rollupIndex, config);
         assertRollupIndex(config, sourceIndex, sourceIndexClone, rollupIndex);
     }
@@ -238,14 +241,15 @@ public void testRollupEmptyIndex() {
         RollupActionConfig config = new RollupActionConfig(randomInterval());
         // Source index has been created in the setup() method
         prepareSourceIndex(sourceIndex);
+        // Clone the source index before rollup deletes it
+        String sourceIndexClone = cloneSourceIndex(sourceIndex);
         rollup(sourceIndex, rollupIndex, config);
         assertRollupIndex(config, sourceIndex, sourceIndexClone, rollupIndex);
     }
 
     public void testCannotRollupIndexWithNoMetrics() {
         // Create a source index that contains no metric fields in its mapping
-        sourceIndex = randomAlphaOfLength(5).toLowerCase(Locale.ROOT);
-        sourceIndexClone = sourceIndex + "-clone";
+        String sourceIndex = "no-metrics-idx-" + randomAlphaOfLength(5).toLowerCase(Locale.ROOT);
         client().admin()
             .indices()
             .prepareCreate(sourceIndex)
@@ -270,7 +274,6 @@ public void testCannotRollupIndexWithNoMetrics() {
             .get();
 
         RollupActionConfig config = new RollupActionConfig(randomInterval());
-        // Source index has been created in the setup() method
         prepareSourceIndex(sourceIndex);
         Exception exception = expectThrows(RollupActionRequestValidationException.class, () -> rollup(sourceIndex, rollupIndex, config));
         assertThat(exception.getMessage(), containsString("does not contain any metric fields"));
@@ -325,10 +328,11 @@ public void testRollupDatastream() throws Exception {
         };
         bulkIndex(dataStreamName, sourceSupplier);
 
-        this.sourceIndex = rollover(dataStreamName).getOldIndex();
-        this.sourceIndexClone = sourceIndex + "-clone";
-        this.rollupIndex = ".rollup-" + sourceIndex;
+        String sourceIndex = rollover(dataStreamName).getOldIndex();
         prepareSourceIndex(sourceIndex);
+        // Clone the source index before rollup deletes it
+        String sourceIndexClone = cloneSourceIndex(sourceIndex);
+        String rollupIndex = "rollup-" + sourceIndex;
         rollup(sourceIndex, rollupIndex, config);
         assertRollupIndex(config, sourceIndex, sourceIndexClone, rollupIndex);
 
@@ -354,7 +358,15 @@ private String randomDateForRange(long start, long end) {
         return DATE_FORMATTER.formatMillis(randomLongBetween(start, end));
     }
 
-    private void cloneSourceIndex(String sourceIndex, String sourceIndexClone) {
+    /**
+     * The source index is deleted at the end of the rollup process.
+     * We clone the source index, so that we validate rollup results against the
+     * source index clone.
+     *
+     * @return the name of the source index clone
+     */
+    private String cloneSourceIndex(String sourceIndex) {
+        String sourceIndexClone = "clone-" + sourceIndex;
         ResizeResponse r = client().admin()
             .indices()
             .prepareResizeIndex(sourceIndex, sourceIndexClone)
@@ -364,6 +376,7 @@ private void cloneSourceIndex(String sourceIndex, String sourceIndexClone) {
             )
             .get();
         assertTrue(r.isAcknowledged());
+        return sourceIndexClone;
     }
 
     private void bulkIndex(SourceSupplier sourceSupplier) throws IOException {
@@ -386,15 +399,15 @@ private void bulkIndex(String indexName, SourceSupplier sourceSupplier) throws I
                 if (response.getFailure().getCause() instanceof VersionConflictEngineException) {
                     // A duplicate event was created by random generator. We should not fail for this
                     // reason.
-                    logger.info("We tried to insert a duplicate: " + response.getFailureMessage());
+                    logger.debug("We tried to insert a duplicate: [{}]", response.getFailureMessage());
                     duplicates++;
                 } else {
                     fail("Failed to index data: " + bulkResponse.buildFailureMessage());
                 }
             }
         }
         int docsIndexed = docCount - duplicates;
-        logger.info("Indexed [" + docsIndexed + "] documents");
+        logger.info("Indexed [{}] documents. Dropped [{}] duplicates.", docsIndexed, duplicates);
         assertHitCount(client().prepareSearch(indexName).setSize(0).get(), docsIndexed);
     }
 
@@ -406,11 +419,6 @@ private void prepareSourceIndex(String sourceIndex) {
             .setSettings(Settings.builder().put(IndexMetadata.INDEX_BLOCKS_WRITE_SETTING.getKey(), true).build())
             .get();
         assertTrue(r.isAcknowledged());
-
-        // The source index is deleted at the end of the rollup process.
-        // We clone the source index, so that we validate rollup results against the
-        // source index clone.
-        cloneSourceIndex(sourceIndex, sourceIndexClone);
     }
 
     private void rollup(String sourceIndex, String rollupIndex, RollupActionConfig config) {