[GitHub] [cassandra] dcapwell commented on a change in pull request #1324: Marcuse/16310

[GitBox <gi...@apache.org>]

dcapwell commented on a change in pull request #1324:
URL: https://github.com/apache/cassandra/pull/1324#discussion_r751437193



##########
File path: src/java/org/apache/cassandra/metrics/TopPartitionTracker.java
##########
@@ -0,0 +1,374 @@
+/*
+ * 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.cassandra.metrics;
+
+import java.nio.ByteBuffer;
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.NavigableSet;
+import java.util.TreeSet;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
+
+import com.google.common.annotations.VisibleForTesting;
+
+import org.apache.cassandra.concurrent.ScheduledExecutors;
+import org.apache.cassandra.config.DatabaseDescriptor;
+import org.apache.cassandra.db.DecoratedKey;
+import org.apache.cassandra.db.SystemKeyspace;
+import org.apache.cassandra.db.rows.Cell;
+import org.apache.cassandra.db.rows.RangeTombstoneMarker;
+import org.apache.cassandra.db.rows.Row;
+import org.apache.cassandra.db.rows.UnfilteredRowIterator;
+import org.apache.cassandra.db.transform.Transformation;
+import org.apache.cassandra.dht.IPartitioner;
+import org.apache.cassandra.dht.Range;
+import org.apache.cassandra.dht.Token;
+import org.apache.cassandra.io.sstable.SSTable;
+import org.apache.cassandra.schema.TableMetadata;
+import org.apache.cassandra.utils.Pair;
+
+/**
+ * Tracks top partitions, currently by size and by tombstone count
+ *
+ * Collects during full and preview (-vd) repair since then we read the full partition
+ *
+ * Note that since we can run sub range repair there might be windows where the top partitions are not correct -
+ * for example, assume we track the top 2 partitions for this node:
+ *
+ * tokens with size:
+ * (a, 100); (b, 40); (c, 10); (d, 100); (e, 50); (f, 10)
+ * - top2: a, d
+ * now a is deleted and we run a repair for keys [a, c]
+ * - top2: b, d
+ * and when we repair [d, f]
+ * - top2: d, e
+ *
+ */
+public class TopPartitionTracker
+{
+    private final static String SIZES = "SIZES";
+    private final static String TOMBSTONES = "TOMBSTONES";

Review comment:
       based off usage, the enum is just a holder to the strings needed to do a CQL query (examples: `SystemKeyspace.getTopPartitions(keyspace, table, SIZES),` and `SystemKeyspace.saveTopPartitions(keyspace, table, SIZES, topSizes.get().top)`); so not a fan of enums here




-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: pr-unsubscribe@cassandra.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org



---------------------------------------------------------------------
To unsubscribe, e-mail: pr-unsubscribe@cassandra.apache.org
For additional commands, e-mail: pr-help@cassandra.apache.org