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https://issues.apache.org/jira/browse/HIVE-26509?focusedWorklogId=812324&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-812324
]
ASF GitHub Bot logged work on HIVE-26509:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 27/Sep/22 02:49
Start Date: 27/Sep/22 02:49
Worklog Time Spent: 10m
Work Description: dengzhhu653 commented on code in PR #3567:
URL: https://github.com/apache/hive/pull/3567#discussion_r980679650
##########
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/leader/AuditLeaderListener.java:
##########
@@ -0,0 +1,117 @@
+/*
+ * 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.hadoop.hive.metastore.leader;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hive.common.TableName;
+import org.apache.hadoop.hive.metastore.ColumnType;
+import org.apache.hadoop.hive.metastore.HiveMetaStore;
+import org.apache.hadoop.hive.metastore.IHMSHandler;
+import org.apache.hadoop.hive.metastore.Warehouse;
+import org.apache.hadoop.hive.metastore.api.AlreadyExistsException;
+import org.apache.hadoop.hive.metastore.api.Table;
+import org.apache.hadoop.hive.metastore.client.builder.TableBuilder;
+
+import java.io.OutputStream;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.nio.charset.StandardCharsets;
+
+import static java.util.Objects.requireNonNull;
+
+public class AuditLeaderListener implements
LeaderElection.LeadershipStateListener {
+ private final Configuration configuration;
+
+ private final Path tableLocation;
+
+ private final static String SERDE =
"org.apache.hadoop.hive.serde2.JsonSerDe";
+ private final static String INPUTFORMAT =
"org.apache.hadoop.mapred.TextInputFormat";
+ private final static String OUTPUTFORMAT =
"org.apache.hadoop.hive.ql.io.IgnoreKeyTextOutputFormat";
+
+ public AuditLeaderListener(TableName tableName, IHMSHandler handler) throws
Exception {
+ requireNonNull(tableName, "tableName is null");
+ requireNonNull(handler, "handler is null");
+ this.configuration = handler.getConf();
+ try {
+ // store the leader info as json + text for human-readable
+ Table table = new TableBuilder()
+ .setCatName(tableName.getCat())
+ .setDbName(tableName.getDb())
+ .setTableName(tableName.getTable())
+ .addCol("leader", ColumnType.STRING_TYPE_NAME)
+ .addCol("name", ColumnType.STRING_TYPE_NAME)
+ .addCol("elected_time", ColumnType.BIGINT_TYPE_NAME)
+ .setSerdeLib(SERDE)
+ .setInputFormat(INPUTFORMAT)
+ .setOutputFormat(OUTPUTFORMAT)
+ .build(handler.getConf());
+ handler.create_table(table);
+ } catch (AlreadyExistsException e) {
+ // ignore
+ }
+
+ Table table = handler.getMS().getTable(tableName.getCat(),
+ tableName.getDb(), tableName.getTable());
+ this.tableLocation = new Path(table.getSd().getLocation());
+ String serde = table.getSd().getSerdeInfo().getSerializationLib();
+ String input = table.getSd().getInputFormat();
+ String output = table.getSd().getOutputFormat();
+ if (!SERDE.equals(serde) || !INPUTFORMAT.equals(input)
+ || !OUTPUTFORMAT.equals(output)) {
+ throw new RuntimeException(tableName + " should be in json + text
format");
+ }
+
+ }
+
+ @Override
+ public void takeLeadership(LeaderElection election) throws Exception {
+ String hostName = getHostname();
+ String message = "{\"leader\": \"" + hostName + "\", \"name\": \""
+ + election.getName() + "\", \"elected_time\": " +
System.currentTimeMillis() + "} \n";
+ Path path = new Path(tableLocation, "leader.json");
+ try {
+ FileSystem fs = Warehouse.getFs(path, configuration);
+ try (OutputStream outputStream = fs.exists(path) ?
+ fs.append(path) :
+ fs.create(path, false)) {
+ outputStream.write(message.getBytes(StandardCharsets.UTF_8));
Review Comment:
this acts the same as putting the entry into the table, this saves us from
connecting HS2 and issuing an insert at HMS side.
Issue Time Tracking
-------------------
Worklog Id: (was: 812324)
Time Spent: 3h (was: 2h 50m)
> Introduce dynamic leader election in HMS
> ----------------------------------------
>
> Key: HIVE-26509
> URL: https://issues.apache.org/jira/browse/HIVE-26509
> Project: Hive
> Issue Type: New Feature
> Components: Standalone Metastore
> Reporter: Zhihua Deng
> Priority: Major
> Labels: pull-request-available
> Time Spent: 3h
> Remaining Estimate: 0h
>
> From HIVE-21841 we have a leader HMS selected by configuring
> metastore.housekeeping.leader.hostname on startup. This approach saves us
> from running duplicated HMS's housekeeping tasks cluster-wide.
> In this jira, we introduce another dynamic leader election: adopt hive lock
> to implement the leader election. Once a HMS owns the lock, then it becomes
> the leader, carries out the housekeeping tasks, and sends heartbeats to renew
> the lock before timeout. If the leader fails to reclaim the lock, then stops
> the already started tasks if it has, the electing event is audited. We can
> achieve a more dynamic leader when the original goes down or in the public
> cloud without well configured property, and reduce the leader’s burdens by
> running these tasks among different leaders.
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