Github user nickwallen commented on a diff in the pull request:
https://github.com/apache/metron/pull/1150#discussion_r209764724
--- Diff:
metron-analytics/metron-profiler-spark/src/main/java/org/apache/metron/profiler/spark/function/ProfileBuilderFunction.java
---
@@ -0,0 +1,107 @@
+/*
+ *
+ * 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.metron.profiler.spark.function;
+
+import org.apache.metron.profiler.DefaultMessageDistributor;
+import org.apache.metron.profiler.MessageDistributor;
+import org.apache.metron.profiler.MessageRoute;
+import org.apache.metron.profiler.ProfileMeasurement;
+import org.apache.metron.profiler.spark.ProfileMeasurementAdapter;
+import org.apache.metron.stellar.dsl.Context;
+import org.apache.spark.api.java.function.MapGroupsFunction;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.lang.invoke.MethodHandles;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
+
+import static java.util.Comparator.comparing;
+import static
org.apache.metron.profiler.spark.BatchProfilerConfig.PERIOD_DURATION;
+import static
org.apache.metron.profiler.spark.BatchProfilerConfig.PERIOD_DURATION_UNITS;
+
+/**
+ * The function responsible for building profiles in Spark.
+ */
+public class ProfileBuilderFunction implements MapGroupsFunction<String,
MessageRoute, ProfileMeasurementAdapter> {
+
+ protected static final Logger LOG =
LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
+
+ private long periodDurationMillis;
+ private Map<String, String> globals;
+
+ public ProfileBuilderFunction(Properties properties, Map<String, String>
globals) {
+ TimeUnit periodDurationUnits =
TimeUnit.valueOf(PERIOD_DURATION_UNITS.get(properties, String.class));
+ int periodDuration = PERIOD_DURATION.get(properties, Integer.class);
+ this.periodDurationMillis =
periodDurationUnits.toMillis(periodDuration);
+ this.globals = globals;
+ }
+
+ /**
+ * Build a profile from a set of message routes.
+ *
+ * <p>This assumes that all of the necessary routes have been provided
+ *
+ * @param group The group identifier.
+ * @param iterator The message routes.
+ * @return
+ */
+ @Override
+ public ProfileMeasurementAdapter call(String group,
Iterator<MessageRoute> iterator) throws Exception {
+ // create the distributor; some settings are unnecessary because it is
cleaned-up immediately after processing the batch
+ int maxRoutes = Integer.MAX_VALUE;
+ long profileTTLMillis = Long.MAX_VALUE;
+ MessageDistributor distributor = new
DefaultMessageDistributor(periodDurationMillis, profileTTLMillis, maxRoutes);
+ Context context = TaskUtils.getContext(globals);
+
+ // sort the messages/routes
+ List<MessageRoute> routes = toStream(iterator)
+ .sorted(comparing(rt -> rt.getTimestamp()))
+ .collect(Collectors.toList());
+ LOG.debug("Building a profile for group '{}' from {} message(s)",
group, routes.size());
+
+ // apply each message/route to build the profile
+ for(MessageRoute route: routes) {
+ distributor.distribute(route, context);
+ }
--- End diff --
> @simonellistonball: Do we have to use groupByKey in the spark
implementation, is it not possible to use reduceByKey to build the profiles...
What we do now is group by (profile, entity, period) to aggregate all of
the messages needed to produce a measurement for any given profile period.
Then those messages are sorted by timestamp and applied to the profile in that
order.
I didn't see an easy way to use `reduceByKey` and ensure that the messages
are applied to the profile in timestamp order. Can you think of an alternative
that maintains the ordering?
---
