1.什么是kudu

在Kudu出现前，由于传统存储系统的局限性，对于数据的快速输入和分析还没有一个完美的解决方案，要么以缓慢的数据输入为代价实现快速分析，要么以缓慢的分析为代价实现数据快速输入。随着快速输入和分析场景越来越多，传统存储层的局限性越来越明显，Kudu应运而生，它的定位介于HDFS和HBase之间，将低延迟随机访问，逐行插入、更新和快速分析扫描融合到一个存储层中，是一个既支持随机读写又支持OLAP分析的存储引擎

kudu应用场景

• 适用于那些既有随机访问，也有批量数据扫描的复合场景
• 高计算量的场景
• 使用了高性能的存储设备，包括使用更多的内存
• 支持数据更新，避免数据反复迁移
• 支持跨地域的实时数据备份和查询

架构

1、Table

表（Table）是数据库中用来存储数据的对象，是有结构的数据集合。kudu中的表具有schema和全局有序的primary key（主键）。kudu中一个table会被水平分成多个被称之为tablet的片段。

2、Tablet

一个 tablet 是一张 table连续的片段，tablet是kudu表的水平分区，类似于HBase的region。每个tablet存储着一定连续range的数据（key），且tablet两两间的range不会重叠。一张表的所有tablet包含了这张表的所有key空间 tablet 会冗余存储。放置到多个 tablet server上，并且在任何给定的时间点，其中一个副本被认为是leader tablet,其余的被认之为follower tablet。每个tablet都可以进行数据的读请求，但只有Leader tablet负责写数据请求

3、Tablet Server

tablet server负责数据存储，并提供数据读写服务 一个 tablet server 存储了table表的tablet，向kudu client 提供读取数据服务。对于给定的 tablet，一个tablet server 充当 leader，其他 tablet server 充当该 tablet 的 follower 副本 只有 leader服务写请求，然而 leader 或 followers 为每个服务提供读请求 。一个 tablet server 可以服务多个 tablets ，并且一个 tablet 可以被多个 tablet servers 服务着

4、Master Server

集群中负责集群管理、元数据管理等功能

2.环境安装

采用docker-composer安装

# 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.
version: "3"
services:
  kudu-master-1:
    image: apache/kudu:${KUDU_QUICKSTART_VERSION:-latest}
    ports:
      - "7051:7051"
      - "8051:8051"
    command: ["master"]
    volumes:
      - kudu-master-1:/var/lib/kudu
    environment:
      - KUDU_MASTERS=kudu-master-1:7051,kudu-master-2:7151,kudu-master-3:7251
      # TODO: Use `host.docker.internal` instead of KUDU_QUICKSTART_IP when it
      # works on Linux (https://github.com/docker/for-linux/issues/264)
      - >
        MASTER_ARGS=--fs_wal_dir=/var/lib/kudu/master
        --rpc_bind_addresses=0.0.0.0:7051
        --rpc_advertised_addresses=${KUDU_QUICKSTART_IP:?Please set KUDU_QUICKSTART_IP environment variable}:7051
        --webserver_port=8051
        --webserver_advertised_addresses=${KUDU_QUICKSTART_IP}:8051
        --webserver_doc_root=/opt/kudu/www
        --stderrthreshold=0
        --use_hybrid_clock=false
        --unlock_unsafe_flags=true

  kudu-master-2:
    image: apache/kudu:${KUDU_QUICKSTART_VERSION:-latest}
    ports:
      - "7151:7151"
      - "8151:8151"
    command: ["master"]
    volumes:
      - kudu-master-2:/var/lib/kudu
    environment:
      - KUDU_MASTERS=kudu-master-1:7051,kudu-master-2:7151,kudu-master-3:7251
      - >
        MASTER_ARGS=--fs_wal_dir=/var/lib/kudu/master
        --rpc_bind_addresses=0.0.0.0:7151
        --rpc_advertised_addresses=${KUDU_QUICKSTART_IP}:7151
        --webserver_port=8151
        --webserver_advertised_addresses=${KUDU_QUICKSTART_IP}:8151
        --webserver_doc_root=/opt/kudu/www
        --stderrthreshold=0
        --use_hybrid_clock=false
        --unlock_unsafe_flags=true
  kudu-master-3:
    image: apache/kudu:${KUDU_QUICKSTART_VERSION:-latest}
    ports:
      - "7251:7251"
      - "8251:8251"
    command: ["master"]
    volumes:
      - kudu-master-3:/var/lib/kudu
    environment:
      - KUDU_MASTERS=kudu-master-1:7051,kudu-master-2:7151,kudu-master-3:7251
      - >
        MASTER_ARGS=--fs_wal_dir=/var/lib/kudu/master
        --rpc_bind_addresses=0.0.0.0:7251
        --rpc_advertised_addresses=${KUDU_QUICKSTART_IP}:7251
        --webserver_port=8251
        --webserver_advertised_addresses=${KUDU_QUICKSTART_IP}:8251
        --webserver_doc_root=/opt/kudu/www
        --stderrthreshold=0
        --use_hybrid_clock=false
        --unlock_unsafe_flags=true
  kudu-tserver-1:
    image: apache/kudu:${KUDU_QUICKSTART_VERSION:-latest}
    depends_on:
      - kudu-master-1
      - kudu-master-2
      - kudu-master-3
    ports:
      - "7050:7050"
      - "8050:8050"
    command: ["tserver"]
    volumes:
      - kudu-tserver-1:/var/lib/kudu
    environment:
      - KUDU_MASTERS=kudu-master-1:7051,kudu-master-2:7151,kudu-master-3:7251
      - >
        TSERVER_ARGS=--fs_wal_dir=/var/lib/kudu/tserver
        --rpc_bind_addresses=0.0.0.0:7050
        --rpc_advertised_addresses=${KUDU_QUICKSTART_IP}:7050
        --webserver_port=8050
        --webserver_advertised_addresses=${KUDU_QUICKSTART_IP}:8050
        --webserver_doc_root=/opt/kudu/www
        --stderrthreshold=0
        --use_hybrid_clock=false
        --unlock_unsafe_flags=true
  kudu-tserver-2:
    image: apache/kudu:${KUDU_QUICKSTART_VERSION:-latest}
    depends_on:
      - kudu-master-1
      - kudu-master-2
      - kudu-master-3
    ports:
      - "7150:7150"
      - "8150:8150"
    command: ["tserver"]
    volumes:
      - kudu-tserver-2:/var/lib/kudu
    environment:
      - KUDU_MASTERS=kudu-master-1:7051,kudu-master-2:7151,kudu-master-3:7251
      - >
        TSERVER_ARGS=--fs_wal_dir=/var/lib/kudu/tserver
        --rpc_bind_addresses=0.0.0.0:7150
        --rpc_advertised_addresses=${KUDU_QUICKSTART_IP}:7150
        --webserver_port=8150
        --webserver_advertised_addresses=${KUDU_QUICKSTART_IP}:8150
        --webserver_doc_root=/opt/kudu/www
        --stderrthreshold=0
        --use_hybrid_clock=false
        --unlock_unsafe_flags=true
  kudu-tserver-3:
    image: apache/kudu:${KUDU_QUICKSTART_VERSION:-latest}
    depends_on:
      - kudu-master-1
      - kudu-master-2
      - kudu-master-3
    ports:
      - "7250:7250"
      - "8250:8250"
    command: ["tserver"]
    volumes:
      - kudu-tserver-3:/var/lib/kudu
    environment:
      - KUDU_MASTERS=kudu-master-1:7051,kudu-master-2:7151,kudu-master-3:7251
      - >
        TSERVER_ARGS=--fs_wal_dir=/var/lib/kudu/tserver
        --rpc_bind_addresses=0.0.0.0:7250
        --rpc_advertised_addresses=${KUDU_QUICKSTART_IP}:7250
        --webserver_port=8250
        --webserver_advertised_addresses=${KUDU_QUICKSTART_IP}:8250
        --webserver_doc_root=/opt/kudu/www
        --stderrthreshold=0
        --use_hybrid_clock=false
        --unlock_unsafe_flags=true
  kudu-tserver-4:
    image: apache/kudu:${KUDU_QUICKSTART_VERSION:-latest}
    depends_on:
      - kudu-master-1
      - kudu-master-2
      - kudu-master-3
    ports:
      - "7350:7350"
      - "8350:8350"
    command: ["tserver"]
    volumes:
      - kudu-tserver-4:/var/lib/kudu
    environment:
      - KUDU_MASTERS=kudu-master-1:7051,kudu-master-2:7151,kudu-master-3:7251
      - >
        TSERVER_ARGS=--fs_wal_dir=/var/lib/kudu/tserver
        --rpc_bind_addresses=0.0.0.0:7350
        --rpc_advertised_addresses=${KUDU_QUICKSTART_IP}:7350
        --webserver_port=8350
        --webserver_advertised_addresses=${KUDU_QUICKSTART_IP}:8350
        --webserver_doc_root=/opt/kudu/www
        --stderrthreshold=0
        --use_hybrid_clock=false
        --unlock_unsafe_flags=true
  kudu-tserver-5:
    image: apache/kudu:${KUDU_QUICKSTART_VERSION:-latest}
    depends_on:
      - kudu-master-1
      - kudu-master-2
      - kudu-master-3
    ports:
      - "7450:7450"
      - "8450:8450"
    command: ["tserver"]
    volumes:
      - kudu-tserver-5:/var/lib/kudu
    environment:
      - KUDU_MASTERS=kudu-master-1:7051,kudu-master-2:7151,kudu-master-3:7251
      - >
        TSERVER_ARGS=--fs_wal_dir=/var/lib/kudu/tserver
        --rpc_bind_addresses=0.0.0.0:7450
        --rpc_advertised_addresses=${KUDU_QUICKSTART_IP}:7450
        --webserver_port=8450
        --webserver_advertised_addresses=${KUDU_QUICKSTART_IP}:8450
        --webserver_doc_root=/opt/kudu/www
        --stderrthreshold=0
        --use_hybrid_clock=false
        --unlock_unsafe_flags=true
volumes:
  kudu-master-1:
  kudu-master-2:
  kudu-master-3:
  kudu-tserver-1:
  kudu-tserver-2:
  kudu-tserver-3:
  kudu-tserver-4:
  kudu-tserver-5:

windows set env

$env:KUDU_QUICKSTART_VERSION = "1.12.0"
$env:KUDU_QUICKSTART_IP= "10.11.68.77"
Get-ChildItem Env:

linux set env

export KUDU_QUICKSTART_VERSION="1.12.0"
export KUDU_QUICKSTART_IP=$(ifconfig | grep "inet " | grep -Fv 127.0.0.1 | awk '{print $2}' | tail -1)

run

docker-compose -f docker/quickstart.yml up -d

stop

docker-compose -f docker/quickstart.yml down

    访问http://localhost:8051/

3.代码工程

 实验目的

实现java对kudu的创建表 ，插入，查询，修改操作

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springboot-demo</artifactId>
        <groupId>com.et</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>kudu</artifactId>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
        <kudu-version>1.12.0</kudu-version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-autoconfigure</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.kudu</groupId>
            <artifactId>kudu-client</artifactId>
            <version>${kudu-version}</version>
        </dependency>

        <!-- For logging messages. -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-simple</artifactId>
            <version>1.7.30</version>
        </dependency>

        <dependency>
            <groupId>org.apache.kudu</groupId>
            <artifactId>kudu-test-utils</artifactId>
            <version>${kudu-version}</version>
            <scope>test</scope>
        </dependency>


    </dependencies>

</project>

example.java

// 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 com.et.kudu;

import java.util.ArrayList;
import java.util.List;

import org.apache.kudu.ColumnSchema;
import org.apache.kudu.Schema;
import org.apache.kudu.Type;
import org.apache.kudu.client.AlterTableOptions;
import org.apache.kudu.client.CreateTableOptions;
import org.apache.kudu.client.Insert;
import org.apache.kudu.client.KuduClient;
import org.apache.kudu.client.KuduException;
import org.apache.kudu.client.KuduPredicate;
import org.apache.kudu.client.KuduPredicate.ComparisonOp;
import org.apache.kudu.client.KuduScanner;
import org.apache.kudu.client.KuduSession;
import org.apache.kudu.client.KuduTable;
import org.apache.kudu.client.PartialRow;
import org.apache.kudu.client.RowResult;
import org.apache.kudu.client.RowResultIterator;
import org.apache.kudu.client.SessionConfiguration.FlushMode;

/*
 * A simple example of using the synchronous Kudu Java client to
 * - Create a table.
 * - Insert rows.
 * - Alter a table.
 * - Scan rows.
 * - Delete a table.
 */
public class Example {
  private static final Double DEFAULT_DOUBLE = 12.345;
  private static final String KUDU_MASTERS = System.getProperty("kuduMasters", "localhost:7051");

  static void createExampleTable(KuduClient client, String tableName)  throws KuduException {
    // Set up a simple schema.
    List<ColumnSchema> columns = new ArrayList<>(2);
    columns.add(new ColumnSchema.ColumnSchemaBuilder("key", Type.INT32)
        .key(true)
        .build());
    columns.add(new ColumnSchema.ColumnSchemaBuilder("value", Type.STRING).nullable(true)
        .build());
    Schema schema = new Schema(columns);

    // Set up the partition schema, which distributes rows to different tablets by hash.
    // Kudu also supports partitioning by key range. Hash and range partitioning can be combined.
    // For more information, see http://kudu.apache.org/docs/schema_design.html.
    CreateTableOptions cto = new CreateTableOptions();
    List<String> hashKeys = new ArrayList<>(1);
    hashKeys.add("key");
    int numBuckets = 8;
    cto.addHashPartitions(hashKeys, numBuckets);

    // Create the table.
    client.createTable(tableName, schema, cto);
    System.out.println("Created table " + tableName);
  }

  static void insertRows(KuduClient client, String tableName, int numRows) throws KuduException {
    // Open the newly-created table and create a KuduSession.
    KuduTable table = client.openTable(tableName);
    KuduSession session = client.newSession();
    session.setFlushMode(FlushMode.AUTO_FLUSH_BACKGROUND);
    for (int i = 0; i < numRows; i++) {
      Insert insert = table.newInsert();
      PartialRow row = insert.getRow();
      row.addInt("key", i);
      // Make even-keyed row have a null 'value'.
      if (i % 2 == 0) {
        row.setNull("value");
      } else {
        row.addString("value", "value " + i);
      }
      session.apply(insert);
    }

    // Call session.close() to end the session and ensure the rows are
    // flushed and errors are returned.
    // You can also call session.flush() to do the same without ending the session.
    // When flushing in AUTO_FLUSH_BACKGROUND mode (the mode recommended
    // for most workloads, you must check the pending errors as shown below, since
    // write operations are flushed to Kudu in background threads.
    session.close();
    if (session.countPendingErrors() != 0) {
      System.out.println("errors inserting rows");
      org.apache.kudu.client.RowErrorsAndOverflowStatus roStatus = session.getPendingErrors();
      org.apache.kudu.client.RowError[] errs = roStatus.getRowErrors();
      int numErrs = Math.min(errs.length, 5);
      System.out.println("there were errors inserting rows to Kudu");
      System.out.println("the first few errors follow:");
      for (int i = 0; i < numErrs; i++) {
        System.out.println(errs[i]);
      }
      if (roStatus.isOverflowed()) {
        System.out.println("error buffer overflowed: some errors were discarded");
      }
      throw new RuntimeException("error inserting rows to Kudu");
    }
    System.out.println("Inserted " + numRows + " rows");
  }

  static void scanTableAndCheckResults(KuduClient client, String tableName, int numRows) throws KuduException {
    KuduTable table = client.openTable(tableName);
    Schema schema = table.getSchema();

    // Scan with a predicate on the 'key' column, returning the 'value' and "added" columns.
    List<String> projectColumns = new ArrayList<>(2);
    projectColumns.add("key");
    projectColumns.add("value");
    projectColumns.add("added");
    int lowerBound = 0;
    KuduPredicate lowerPred = KuduPredicate.newComparisonPredicate(
        schema.getColumn("key"),
        ComparisonOp.GREATER_EQUAL,
        lowerBound);
    int upperBound = numRows / 2;
    KuduPredicate upperPred = KuduPredicate.newComparisonPredicate(
        schema.getColumn("key"),
        ComparisonOp.LESS,
        upperBound);
    KuduScanner scanner = client.newScannerBuilder(table)
        .setProjectedColumnNames(projectColumns)
        .addPredicate(lowerPred)
        .addPredicate(upperPred)
        .build();

    // Check the correct number of values and null values are returned, and
    // that the default value was set for the new column on each row.
    // Note: scanning a hash-partitioned table will not return results in primary key order.
    int resultCount = 0;
    int nullCount = 0;
    while (scanner.hasMoreRows()) {
      RowResultIterator results = scanner.nextRows();
      while (results.hasNext()) {
        RowResult result = results.next();
        if (result.isNull("value")) {
          nullCount++;
        }
        double added = result.getDouble("added");
        if (added != DEFAULT_DOUBLE) {
          throw new RuntimeException("expected added=" + DEFAULT_DOUBLE +
              " but got added= " + added);
        }
        resultCount++;
      }
    }
    int expectedResultCount = upperBound - lowerBound;
    if (resultCount != expectedResultCount) {
      throw new RuntimeException("scan error: expected " + expectedResultCount +
          " results but got " + resultCount + " results");
    }
    int expectedNullCount = expectedResultCount / 2 + (numRows % 2 == 0 ? 1 : 0);
    if (nullCount != expectedNullCount) {
      throw new RuntimeException("scan error: expected " + expectedNullCount +
          " rows with value=null but found " + nullCount);
    }
    System.out.println("Scanned some rows and checked the results");
  }

  public static void main(String[] args) {
    System.out.println("-----------------------------------------------");
    System.out.println("Will try to connect to Kudu master(s) at " + KUDU_MASTERS);
    System.out.println("Run with -DkuduMasters=master-0:port,master-1:port,... to override.");
    System.out.println("-----------------------------------------------");
    String tableName = "java_example-" + System.currentTimeMillis();
    KuduClient client = new KuduClient.KuduClientBuilder(KUDU_MASTERS).build();

    try {
      createExampleTable(client, tableName);

      int numRows = 150;
      insertRows(client, tableName, numRows);

      // Alter the table, adding a column with a default value.
      // Note: after altering the table, the table needs to be re-opened.
      AlterTableOptions ato = new AlterTableOptions();
      ato.addColumn("added", org.apache.kudu.Type.DOUBLE, DEFAULT_DOUBLE);
      client.alterTable(tableName, ato);
      System.out.println("Altered the table");

      scanTableAndCheckResults(client, tableName, numRows);
    } catch (Exception e) {
      e.printStackTrace();
    } finally {
      try {
        client.deleteTable(tableName);
        System.out.println("Deleted the table");
      } catch (Exception e) {
        e.printStackTrace();
      } finally {
        try {
          client.shutdown();
        } catch (Exception e) {
          e.printStackTrace();
        }
      }
    }
  }
}

以上只是一些关键代码，所有代码请参见下面代码仓库

代码仓库

• GitHub - Harries/springboot-demo: a simple springboot demo with some components for example: redis,solr,rockmq and so on.

4.测试

 测试创建表

@Test
public void testCreateExampleTable() throws KuduException {
    String tableName = "test_create_example";
    Example.createExampleTable(client, tableName);
    assertTrue(client.tableExists(tableName));
}

插入数据

@Test
public void testInsertRows() throws KuduException {
    String tableName = "test_create_example";
   // Example.insertRows(client,tableName,100);
    System.out.println(client.getTableStatistics(tableName).getLiveRowCount());
}

dashboard可以看到我们创建的表和记录条数

5.引用

• Apache Kudu - Fast Analytics on Fast Data
• Spring Boot集成kudu快速入门Demo | Harries Blog™