Limit IndexRequest toString() length (#22832)

Limits the length of `IndexRequest#toString` which also limits the size of the task description generated for `IndexRequest`s. If the document being written is larger than 2kb we skip logging the _source entirely. This is because truncating the source is tricky and it isn't worth it.

core/src/main/java/org/elasticsearch/action/index/IndexRequest.java

@@ -26,6 +26,7 @@ import org.elasticsearch.action.CompositeIndicesRequest;
 import org.elasticsearch.action.DocWriteRequest;
 import org.elasticsearch.action.RoutingMissingException;
 import org.elasticsearch.action.support.replication.ReplicatedWriteRequest;
+import org.elasticsearch.action.support.replication.ReplicationRequest;
 import org.elasticsearch.client.Requests;
 import org.elasticsearch.cluster.metadata.MappingMetaData;
 import org.elasticsearch.cluster.metadata.MetaData;
@@ -36,6 +37,7 @@ import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.lucene.uid.Versions;
+import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
@@ -70,6 +72,13 @@ import static org.elasticsearch.action.ValidateActions.addValidationError;
  */
 public class IndexRequest extends ReplicatedWriteRequest<IndexRequest> implements DocWriteRequest<IndexRequest>, CompositeIndicesRequest {
 
+    /**
+     * Max length of the source document to include into toString()
+     *
+     * @see ReplicationRequest#createTask(long, java.lang.String, java.lang.String, org.elasticsearch.tasks.TaskId)
+     */
+    static final int MAX_SOURCE_LENGTH_IN_TOSTRING = 2048;
+
     private String type;
     private String id;
     @Nullable
@@ -606,7 +615,12 @@ public class IndexRequest extends ReplicatedWriteRequest<IndexRequest> implement
     public String toString() {
         String sSource = "_na_";
         try {
-            sSource = XContentHelper.convertToJson(source, false);
+            if (source.length() > MAX_SOURCE_LENGTH_IN_TOSTRING) {
+                sSource = "n/a, actual length: [" + new ByteSizeValue(source.length()).toString() + "], max length: " +
+                    new ByteSizeValue(MAX_SOURCE_LENGTH_IN_TOSTRING).toString();
+            } else {
+                sSource = XContentHelper.convertToJson(source, false);
+            }
         } catch (Exception e) {
             // ignore
         }

core/src/test/java/org/elasticsearch/action/index/IndexRequestTests.java

@@ -27,6 +27,7 @@ import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.io.stream.BytesStreamOutput;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.xcontent.XContentType;
+import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.index.VersionType;
 import org.elasticsearch.index.seqno.SequenceNumbersService;
 import org.elasticsearch.index.shard.ShardId;
@@ -34,6 +35,7 @@ import org.elasticsearch.rest.RestStatus;
 import org.elasticsearch.test.ESTestCase;
 
 import java.io.IOException;
+import java.io.UnsupportedEncodingException;
 import java.util.Arrays;
 import java.util.Base64;
 import java.util.HashSet;
@@ -202,4 +204,18 @@ public class IndexRequestTests extends ESTestCase {
             }
         }
     }
+
+    public void testToStringSizeLimit() throws UnsupportedEncodingException {
+        IndexRequest request = new IndexRequest("index", "type");
+
+        String source = "{\"name\":\"value\"}";
+        request.source(source);
+        assertEquals("index {[index][type][null], source[" + source + "]}", request.toString());
+
+        source = "{\"name\":\"" + randomUnicodeOfLength(IndexRequest.MAX_SOURCE_LENGTH_IN_TOSTRING) + "\"}";
+        request.source(source);
+        int actualBytes = source.getBytes("UTF-8").length;
+        assertEquals("index {[index][type][null], source[n/a, actual length: [" + new ByteSizeValue(actualBytes).toString() +
+                "], max length: " + new ByteSizeValue(IndexRequest.MAX_SOURCE_LENGTH_IN_TOSTRING).toString() + "]}", request.toString());
+    }
 }