Github user ramkrish86 commented on a diff in the pull request:
https://github.com/apache/phoenix/pull/8#discussion_r16765696
--- Diff:
phoenix-core/src/main/java/org/apache/phoenix/schema/stat/StatisticsCollector.java
---
@@ -0,0 +1,295 @@
+/*
+ * 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.phoenix.schema.stat;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.hbase.Cell;
+import org.apache.hadoop.hbase.Coprocessor;
+import org.apache.hadoop.hbase.CoprocessorEnvironment;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.KeyValue;
+import org.apache.hadoop.hbase.KeyValueUtil;
+import org.apache.hadoop.hbase.client.Scan;
+import org.apache.hadoop.hbase.coprocessor.BaseRegionObserver;
+import org.apache.hadoop.hbase.coprocessor.CoprocessorException;
+import org.apache.hadoop.hbase.coprocessor.CoprocessorService;
+import org.apache.hadoop.hbase.coprocessor.ObserverContext;
+import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
+import org.apache.hadoop.hbase.protobuf.ResponseConverter;
+import org.apache.hadoop.hbase.regionserver.HRegion;
+import org.apache.hadoop.hbase.regionserver.InternalScanner;
+import org.apache.hadoop.hbase.regionserver.KeyValueScanner;
+import org.apache.hadoop.hbase.regionserver.RegionScanner;
+import org.apache.hadoop.hbase.regionserver.ScanType;
+import org.apache.hadoop.hbase.regionserver.Store;
+import org.apache.hadoop.hbase.regionserver.StoreScanner;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.phoenix.coprocessor.generated.StatCollectorProtos;
+import
org.apache.phoenix.coprocessor.generated.StatCollectorProtos.StatCollectRequest;
+import
org.apache.phoenix.coprocessor.generated.StatCollectorProtos.StatCollectResponse;
+import
org.apache.phoenix.coprocessor.generated.StatCollectorProtos.StatCollectResponse.Builder;
+import
org.apache.phoenix.coprocessor.generated.StatCollectorProtos.StatCollectService;
+import org.apache.phoenix.hbase.index.util.ImmutableBytesPtr;
+import org.apache.phoenix.schema.PDataType;
+import org.apache.phoenix.schema.PhoenixArray;
+import org.apache.phoenix.util.SchemaUtil;
+
+import com.google.protobuf.RpcCallback;
+import com.google.protobuf.RpcController;
+import com.google.protobuf.Service;
+
+/**
+ * An endpoint implementation that allows to collect the stats for a given
+ * region and groups the stat per family. This is also an RegionObserver
that
+ * collects the information on compaction also. The user would be allowed
to
+ * invoke this endpoint and thus populate the Phoenix stats table with the
max
+ * key, min key and guide posts for the given region. The stats can be
consumed
+ * by the stats associated with every PTable and the same can be used to
+ * parallelize the queries
+ */
+public class StatisticsCollector extends BaseRegionObserver implements
CoprocessorService,
+ Coprocessor, StatisticsTracker, StatCollectService.Interface {
+
+ public static void addToTable(HTableDescriptor desc) throws IOException {
+ desc.addCoprocessor(StatisticsCollector.class.getName());
+ }
+
+ private byte[] min;
+ private byte[] max;
+ private long guidepostDepth;
+ private long byteCount = 0;
+ private List<byte[]> guidePosts = new ArrayList<byte[]>();
+ private Set<byte[]> familyMap = new
TreeSet<byte[]>(Bytes.BYTES_COMPARATOR);
+ private RegionCoprocessorEnvironment env;
+ protected StatisticsTable stats;
+ private static final Log LOG =
LogFactory.getLog(StatCollectService.class);
+
+ @Override
+ public void collectStat(RpcController controller, StatCollectRequest
request,
+ RpcCallback<StatCollectResponse> done) {
+ HRegion region = env.getRegion();
+ if (familyMap != null) {
+ familyMap.clear();
+ }
+ Scan scan = new Scan();
+ // We should have a mechanism to set the caching here.
+ // TODO : Should the scan object be coming from the endpoint?
+ scan.setCaching(1000);
+ // TODO : Should we scan fully or should we do as done StatsManagerImpl
+ // reading the
+ // first row and the
+ // last row after setting scan.setReserved(true). But doing so we
cannot get
+ // the guideposts
+ RegionScanner scanner = null;
+ int count = 0;
+ try {
+ scanner = region.getScanner(scan);
+ List<Cell> results = new ArrayList<Cell>();
+ boolean hasMore = true;
+ while (hasMore) {
+ // Am getting duplicates here? Need to avoid that
+ hasMore = scanner.next(results);
+ updateStat(results);
+ count += results.size();
+ results.clear();
+ while (!hasMore) {
+ break;
+ }
+ }
+ } catch (IOException e) {
+ LOG.error(e);
+ ResponseConverter.setControllerException(controller, e);
+ } finally {
+ if (scanner != null) {
+ try {
+ scanner.close();
+ IOException toThrow = null;
+ try {
+ // update the statistics table
+ for (byte[] fam : familyMap) {
+ byte[] tableKey =
SchemaUtil.getTableKey(request.getTenantIdBytes().toByteArray(),
+ request.getSchemaNameBytes().toByteArray(),
region.getRegionInfo().getTable()
+ .getName());
+ stats.updateStats(new StatisticsWriter(tableKey,
+
Bytes.toBytes(region.getRegionInfo().getRegionNameAsString())), this, fam);
+ }
+ } catch (IOException e) {
+ LOG.error("Failed to update statistics table!", e);
+ toThrow = e;
+ }
+ } catch (IOException e) {
+ LOG.error(e);
+ ResponseConverter.setControllerException(controller, e);
+ }
+ }
+ }
+ Builder newBuilder = StatCollectResponse.newBuilder();
+ newBuilder.setRowsScanned(count);
+ StatCollectResponse result = newBuilder.build();
+ done.run(result);
+ }
+
+ /**
+ * Update the current statistics based on the lastest batch of
key-values from
+ * the underlying scanner
+ *
+ * @param results
+ * next batch of {@link KeyValue}s
+ */
+ protected void updateStat(final List<Cell> results) {
+ for (Cell c : results) {
+ updateStatistic(KeyValueUtil.ensureKeyValue(c));
+ }
+ }
+
+ @Override
+ public Service getService() {
+ return
StatCollectorProtos.StatCollectService.newReflectiveService(this);
+ }
+
+ @Override
+ public void start(CoprocessorEnvironment env) throws IOException {
+ if (env instanceof RegionCoprocessorEnvironment) {
+ this.env = (RegionCoprocessorEnvironment) env;
+ } else {
+ throw new CoprocessorException("Must be loaded on a table region!");
+ }
+ HTableDescriptor desc = ((RegionCoprocessorEnvironment)
env).getRegion().getTableDesc();
+ // Get the stats table associated with the current table on which the
CP is
+ // triggered
+ stats = StatisticsTable.getStatisticsTableForCoprocessor(env,
desc.getName());
+ guidepostDepth = env.getConfiguration().getLong(
+ StatisticsConstants.HISTOGRAM_BYTE_DEPTH_CONF_KEY,
+ StatisticsConstants.HISTOGRAM_DEFAULT_BYTE_DEPTH);
+ }
+
+ @Override
+ public void stop(CoprocessorEnvironment arg0) throws IOException {
+ stats.close();
+ }
+
+ @Override
+ public InternalScanner
preCompactScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c,
+ Store store, List<? extends KeyValueScanner> scanners, ScanType
scanType, long earliestPutTs,
+ InternalScanner s) throws IOException {
+ // TODO : Major concern here is that we cannot get the complete name
of the table with schema and tenantId here.
--- End diff --
Changed this. Let me check if it is woking fine. If so then no problem.
Can remove the TODO.
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