**Build scan:**
https://gradle-enterprise.elastic.co/s/4ljosxkpgtu6g/tests/:x-pack:plugin:ilm:qa:multi-node:javaRestTest/org.elasticsearch.xpack.ilm.actions.DownsampleActionIT/testTsdbDataStreams
**Reproduction line:**
```
./gradlew ':x-pack:plugin:ilm:qa:multi-node:javaRestTest' --tests "org.elasticsearch.xpack.ilm.actions.DownsampleActionIT.testTsdbDataStreams" -Dtests.seed=1BEA31EF00B903EE -Dtests.locale=ar-SA -Dtests.timezone=Pacific/Galapagos -Druntime.java=21
```

**Applicable branches:**
main

**Reproduces locally?:**
No

**Failure history:**
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.xpack.ilm.actions.DownsampleActionIT&tests.test=testTsdbDataStreams
**Failure excerpt:**
```
java.lang.AssertionError: Cannot retrieve rollup index name

  at __randomizedtesting.SeedInfo.seed([1BEA31EF00B903EE:BBD92C85FE15FC3E]:0)
  at org.junit.Assert.fail(Assert.java:88)
  at org.junit.Assert.assertTrue(Assert.java:41)
  at org.junit.Assert.assertNotNull(Assert.java:712)
  at org.elasticsearch.xpack.ilm.actions.DownsampleActionIT.testTsdbDataStreams(DownsampleActionIT.java:339)
  at jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
  at java.lang.reflect.Method.invoke(Method.java:580)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.invoke(RandomizedRunner.java:1758)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$8.evaluate(RandomizedRunner.java:946)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$9.evaluate(RandomizedRunner.java:982)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$10.evaluate(RandomizedRunner.java:996)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleSetupTeardownChained$1.evaluate(TestRuleSetupTeardownChained.java:48)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleThreadAndTestName$1.evaluate(TestRuleThreadAndTestName.java:45)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:390)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.forkTimeoutingTask(ThreadLeakControl.java:843)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$3.evaluate(ThreadLeakControl.java:490)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.runSingleTest(RandomizedRunner.java:955)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$5.evaluate(RandomizedRunner.java:840)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$6.evaluate(RandomizedRunner.java:891)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$7.evaluate(RandomizedRunner.java:902)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleStoreClassName$1.evaluate(TestRuleStoreClassName.java:38)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleAssertionsRequired$1.evaluate(TestRuleAssertionsRequired.java:53)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleIgnoreTestSuites$1.evaluate(TestRuleIgnoreTestSuites.java:47)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:390)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.lambda$forkTimeoutingTask$0(ThreadLeakControl.java:850)
  at java.lang.Thread.run(Thread.java:1583)

```
x-pack/plugin/ilm/qa/multi-node/src/javaRestTest/java/org/elasticsearch/xpack/ilm/actions/DownsampleActionIT.java
Map<String, Object> settings = getOnlyIndexSettings(client(), rollupIndex);
            assertEquals(originalIndex, settings.get(IndexMetadata.INDEX_DOWNSAMPLE_SOURCE_NAME.getKey()));
            assertEquals(policy, settings.get(LifecycleSettings.LIFECYCLE_NAME_SETTING.getKey()));
            assertEquals(DownsampleTaskStatus.SUCCESS.toString(), settings.get(IndexMetadata.INDEX_DOWNSAMPLE_STATUS.getKey()));
        });
    }
    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/100271")
    public void testTsdbDataStreams() throws Exception {
        
        DateHistogramInterval fixedInterval = ConfigTestHelpers.randomInterval();
        createNewSingletonPolicy(client(), policy, "warm", new DownsampleAction(fixedInterval, DownsampleAction.DEFAULT_WAIT_TIMEOUT));
        
        Request createIndexTemplateRequest = new Request("POST", "/_index_template/" + dataStream);
        createIndexTemplateRequest.setJsonEntity(
            Strings.format(TEMPLATE, dataStream, "2006-01-08T23:40:53.384Z", "2021-01-08T23:40:53.384Z", policy)
        );
        assertOK(client().performRequest(createIndexTemplateRequest));
        index(client(), dataStream, true, null, "@timestamp", "2020-01-01T05:10:00Z", "volume", 11.0, "metricset", randomAlphaOfLength(5));
        String backingIndexName = DataStream.getDefaultBackingIndexName(dataStream, 1);
        assertBusy(
            () -> assertThat(
                "index must wait in the " + CheckNotDataStreamWriteIndexStep.NAME + " until it is not the write index anymore",
                explainIndex(client(), backingIndexName).get("step"),
                is(CheckNotDataStreamWriteIndexStep.NAME)
            ),
            30,
            TimeUnit.SECONDS
        );