Github user mattyb149 commented on a diff in the pull request:
https://github.com/apache/nifi/pull/2180#discussion_r160448342
--- Diff:
nifi-nar-bundles/nifi-mongodb-bundle/nifi-mongodb-processors/src/main/java/org/apache/nifi/processors/mongodb/RunMongoAggregation.java
---
@@ -0,0 +1,180 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.nifi.processors.mongodb;
+
+import com.mongodb.BasicDBObject;
+import com.mongodb.client.AggregateIterable;
+import com.mongodb.client.MongoCollection;
+import com.mongodb.client.MongoCursor;
+import org.apache.nifi.annotation.behavior.InputRequirement;
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.components.ValidationResult;
+import org.apache.nifi.components.Validator;
+import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.processor.ProcessContext;
+import org.apache.nifi.processor.ProcessSession;
+import org.apache.nifi.processor.Relationship;
+import org.apache.nifi.processor.exception.ProcessException;
+import org.bson.conversions.Bson;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+@Tags({"mongo", "aggregation", "aggregate"})
+@CapabilityDescription("A processor that runs an aggregation query at
user-defined intervals.")
--- End diff --
Consider adding @EventDriven here, although if you do, you should update
the capability description to say it may also run the query upon receiving an
input flow file.
---
