deubg logging to TruncateTranslogIT

To see what data paths are used.

core/src/test/java/org/elasticsearch/index/translog/TruncateTranslogIT.java

@@ -56,6 +56,7 @@ import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.test.ESIntegTestCase;
 import org.elasticsearch.test.InternalTestCluster;
 import org.elasticsearch.test.engine.MockEngineSupport;
+import org.elasticsearch.test.junit.annotations.TestLogging;
 import org.elasticsearch.test.transport.MockTransportService;
 
 import java.io.IOException;
@@ -82,6 +83,7 @@ import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.notNullValue;
 
 @ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.SUITE, numDataNodes = 0)
+@TestLogging("_root:DEBUG")
 public class TruncateTranslogIT extends ESIntegTestCase {
 
     @Override
@@ -108,8 +110,8 @@ public class TruncateTranslogIT extends ESIntegTestCase {
         ));
 
         // Index some documents
-        logger.info("--> indexing more doc to be kept");
         int numDocsToKeep = randomIntBetween(0, 100);
+        logger.info("--> indexing [{}] docs to be kept", numDocsToKeep);
         IndexRequestBuilder[] builders = new IndexRequestBuilder[numDocsToKeep];
         for (int i = 0; i < builders.length; i++) {
             builders[i] = client().prepareIndex("test", "type").setSource("foo", "bar");