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基于C#+Thrift操作HBase实践

程序员文章站 2022-05-23 16:06:43
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在基于HBase数据库的开发中,对应Java语言来说,可以直接使用HBase的原生API来操作HBase表数据,当然你要是不嫌麻烦可以使用Thrift客户端Java API,这里有我曾经使用过的 HBase Thrift客户端Java API实践,可以参考。对于具有其他编程语言背景的开发人员,为

在基于HBase数据库的开发中,对应Java语言来说,可以直接使用HBase的原生API来操作HBase表数据,当然你要是不嫌麻烦可以使用Thrift客户端Java API,这里有我曾经使用过的 HBase Thrift客户端Java API实践,可以参考。对于具有其他编程语言背景的开发人员,为了获取HBase带来的好处,那么就可以选择使用HBase Thrift客户端对应编程语言的API,来实现与HBase的交互。
这里,我们使用C#客户端来操作HBase。HBase的Thrift接口的定义,可以通过链接http://svn.apache.org/viewvc/hbase/trunk/hbase-server/src/main/resources/org/apache/hadoop/hbase/thrift/Hbase.thrift?view=markup看到,我们需要安装Thrift编译器,才能生成HBase跨语言的API,这里,我使用的版本是0.9.0。需要注意的是,一定要保证,安装了某个版本Thrift的Thrift编译器,在导入对应语言库的时候,版本一定要统一,否则就会出现各种各样的问题,因为不同Thrift版本,对应编程语言的库API可能有变化。
首先,下载上面链接的内容,保存为Hbase.thrift。
然后,执行如下命令,生成C#编程语言的HBase Thrift客户端API:

[hadoop@master hbase]$ thrift --gen csharp Hbase.thrift
[hadoop@master hbase]$ ls
gen-csharp

这里,我们基于C#语言,使用HBase 的Thrift 客户端API访问HBase表。事实上,如果使用Java来实现对HBase表的操作,最好是使用HBase的原生API,无论从性能还是便利性方面,都会提供更好的体验。使用Thrift API访问,实际也是在HBase API之上进行了一层封装,可能初次使用Thrift API感觉很别扭,有时候还要参考Thrift服务端的实现代码。
准备工作如下:

    1. 下载Thrift软件包,解压缩后,拷贝thrift-0.9.0/lib/java/src下面的代码到工作区(开发工具中)
    2. 将上面生成的gen-csharp目录中代码拷贝到工作区
    3. 保证HBase集群正常运行,接着启动HBase的Thrift服务,执行如下命令:
bin/hbase thrift -b master -p 9090 start

上面,HBase的Thrift服务端口为9090,下面通过Thrift API访问的时候,需要用到,而不是HBase的服务端口(默认60000)。
接着,实现一个简单的例子,访问Hbase表。
首先,我们通过HBase Shell创建一个表:

create 'test_info', 'info'

表名为test_info,列簇名称为info。
然后,我们开始基于上面生成的Thrift代码来实现对HBase表的操作。
这里,我们实际上是对HBase Thrift客户端Java API实践中的Java代码进行了翻译,改写成C#语言的相关操作。我们在客户端,进行了一层抽象,更加便于传递各种参数,抽象类为AbstractHBaseThriftService,对应的命名空间为HbaseThrift.HBase.Thrift,该类实现代码如下所示:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Thrift.Transport;
using Thrift.Protocol;
namespace HbaseThrift.HBase.Thrift
{
    public abstract class AbstractHBaseThriftService
    {
        protected static readonly string CHARSET = "UTF-8";
	    private string host = "localhost";
	    private int port = 9090;
	    private readonly TTransport transport;
	    protected readonly Hbase.Client client;
        public AbstractHBaseThriftService() : this("localhost", 9090)
        {
        }
        public AbstractHBaseThriftService(string host, int port)
        {
            this.host = host;
            this.port = port;
            transport = new TSocket(host, port);
            TProtocol protocol = new TBinaryProtocol(transport, true, true);
            client = new Hbase.Client(protocol);
        }
        public void Open() {
            if (transport != null)
            {
                transport.Open();
            }
	    }
        public void Close()
        {
            if (transport != null)
            {
                transport.Close();
            }
        }
        public abstract List GetTables();
	    public abstract void Update(string table, string rowKey, bool writeToWal,
			string fieldName, string fieldValue, Dictionary attributes);
        public abstract void Update(string table, string rowKey, bool writeToWal,
			Dictionary fieldNameValues, Dictionary attributes);
	    public abstract void DeleteCell(string table, string rowKey, bool writeToWal,
			    string column, Dictionary attributes);
	    public abstract void DeleteCells(string table, string rowKey, bool writeToWal,
			    List columns, Dictionary attributes);
	     public abstract void DeleteRow(string table, string rowKey,
		            Dictionary attributes);
	    public abstract int ScannerOpen(string table, string startRow, List columns,
	            Dictionary attributes);
	    public abstract int ScannerOpen(string table, string startRow, string stopRow, List columns,
	            Dictionary attributes);
	    public abstract int ScannerOpenWithPrefix(string table, string startAndPrefix,
                List columns, Dictionary attributes);
	    public abstract int ScannerOpenTs(string table, string startRow,
	            List columns, long timestamp, Dictionary attributes);
	    public abstract int ScannerOpenTs(string table, string startRow, string stopRow,
	            List columns, long timestamp, Dictionary attributes);
	    public abstract List ScannerGetList(int id, int nbRows);
	    public abstract List ScannerGet(int id);
	    public abstract List GetRow(string table, string row,
		            Dictionary attributes);
	    public abstract List GetRows(string table,
                 List rows, Dictionary attributes);
	    public abstract List GetRowsWithColumns(string table,
                 List rows, List columns, Dictionary attributes);
	    public abstract void ScannerClose(int id);
	    /**
	     * Iterate result rows(just for test purpose)
	     * @param result
	     */
	    public abstract void IterateResults(TRowResult result);
    }
}

这里,简单叙述一下,我们提供的客户端API的基本功能:

  • 建立到Thrift服务的连接:Open()
  • 获取到HBase中的所有表名:GetTables()
  • 更新HBase表记录:Update()
  • 删除HBase表中一行的记录的数据(cell):DeleteCell()和DeleCells()
  • 删除HBase表中一行记录:deleteRow()
  • 打开一个Scanner,返回id:ScannerOpen()、ScannerOpenWithPrefix()和ScannerOpenTs();然后用返回的id迭代记录:ScannerGetList()和ScannerGet()
  • 获取一行记录结果:GetRow()、GetRows()和GetRowsWithColumns()
  • 关闭一个Scanner:ScannerClose()
  • 迭代结果,用于调试:IterateResults()

比如,我们想要实现分页的逻辑,可能和传统的关系型数据库操作有些不同。基于HBase表的实现是,首先打开一个Scanner实例(例如调用ScannerOpen()),返回一个id,然后再使用该id,调用ScannerGetList()方法(可以指定每次返回几条记录的变量nbRows的值),返回一个记录列表,反复调用该ScannerGetList()方法,直到此次没有结果返回为止。后面会通过测试用例来实际体会。
现在,我们基于上抽象出来的客户端操作接口,给出一个基本的实现,代码如下所示:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace HbaseThrift.HBase.Thrift
{
    class HBaseThriftClient : AbstractHBaseThriftService
    {
        public HBaseThriftClient() : this("localhost", 9090)
        {
        }
        public HBaseThriftClient(string host, int port) : base(host, port)
        {
        }
        public override List GetTables()
        {
            List tables = client.getTableNames();
            List list = new List();
            foreach(byte[] table in tables)
            {
                list.Add(Decode(table));
            }
            return list;
        }
        public override void Update(string table, string rowKey, bool writeToWal, string fieldName, string fieldValue, Dictionary attributes)
        {
            byte[] tableName = Encode(table);
            byte[] row = Encode(rowKey);
            Dictionary encodedAttributes = EncodeAttributes(attributes);
            List mutations = new List();
            Mutation mutation = new Mutation();
            mutation.IsDelete = false;
            mutation.WriteToWAL = writeToWal;
            mutation.Column = Encode(fieldName);
            mutation.Value = Encode(fieldValue);
            mutations.Add(mutation);
            client.mutateRow(tableName, row, mutations, encodedAttributes);
        }
        public override void Update(string table, string rowKey, bool writeToWal, Dictionary fieldNameValues, Dictionary attributes)
        {
            byte[] tableName = Encode(table);
            byte[] row = Encode(rowKey);
            Dictionary encodedAttributes = EncodeAttributes(attributes);
            List mutations = new List();
            foreach (KeyValuePair pair in fieldNameValues)
            {
                Mutation mutation = new Mutation();
                mutation.IsDelete = false;
                mutation.WriteToWAL = writeToWal;
                mutation.Column = Encode(pair.Key);
                mutation.Value = Encode(pair.Value);
                mutations.Add(mutation);
            }
            client.mutateRow(tableName, row, mutations, encodedAttributes);
        }
        public override void DeleteCell(string table, string rowKey, bool writeToWal, string column, Dictionary attributes)
        {
            byte[] tableName = Encode(table);
            byte[] row = Encode(rowKey);
            Dictionary encodedAttributes = EncodeAttributes(attributes);
            List mutations = new List();
            Mutation mutation = new Mutation();
            mutation.IsDelete = true;
            mutation.WriteToWAL = writeToWal;
            mutation.Column = Encode(column);
            mutations.Add(mutation);
            client.mutateRow(tableName, row, mutations, encodedAttributes);
        }
        public override void DeleteCells(string table, string rowKey, bool writeToWal, List columns, Dictionary attributes)
        {
            byte[] tableName = Encode(table);
            byte[] row = Encode(rowKey);
            Dictionary encodedAttributes = EncodeAttributes(attributes);
            List mutations = new List();
            foreach (string column in columns)
            {
                Mutation mutation = new Mutation();
                mutation.IsDelete = true;
                mutation.WriteToWAL = writeToWal;
                mutation.Column = Encode(column);
                mutations.Add(mutation);
            }
            client.mutateRow(tableName, row, mutations, encodedAttributes);
        }
        public override void DeleteRow(string table, string rowKey, Dictionary attributes)
        {
            byte[] tableName = Encode(table);
            byte[] row = Encode(rowKey);
            Dictionary encodedAttributes = EncodeAttributes(attributes);
            client.deleteAllRow(tableName, row, encodedAttributes);
        }
        public override int ScannerOpen(string table, string startRow, List columns, Dictionary attributes)
        {
            byte[] tableName = Encode(table);
            byte[] start = Encode(startRow);
            List encodedColumns = EncodeStringList(columns);
            Dictionary encodedAttributes = EncodeAttributes(attributes);
            return client.scannerOpen(tableName, start, encodedColumns, encodedAttributes);
        }
        public override int ScannerOpen(string table, string startRow, string stopRow, List columns, Dictionary attributes)
        {
            byte[] tableName = Encode(table);
            byte[] start = Encode(startRow);
            byte[] stop = Encode(stopRow);
            List encodedColumns = EncodeStringList(columns);
            Dictionary encodedAttributes = EncodeAttributes(attributes);
            return client.scannerOpenWithStop(tableName, start, stop, encodedColumns, encodedAttributes);
        }
        public override int ScannerOpenWithPrefix(string table, string startAndPrefix, List columns, Dictionary attributes)
        {
            byte[] tableName = Encode(table);
            byte[] prefix = Encode(startAndPrefix);
            List encodedColumns = EncodeStringList(columns);
            Dictionary encodedAttributes = EncodeAttributes(attributes);
            return client.scannerOpenWithPrefix(tableName, prefix, encodedColumns, encodedAttributes);
        }
        public override int ScannerOpenTs(string table, string startRow, List columns, long timestamp, Dictionary attributes)
        {
            byte[] tableName = Encode(table);
            byte[] start = Encode(startRow);
            List encodedColumns = EncodeStringList(columns);
            Dictionary encodedAttributes = EncodeAttributes(attributes);
            return client.scannerOpenTs(tableName, start, encodedColumns, timestamp, encodedAttributes);
        }
        public override int ScannerOpenTs(string table, string startRow, string stopRow, List columns, long timestamp, Dictionary attributes)
        {
            byte[] tableName = Encode(table);
            byte[] start = Encode(startRow);
            byte[] stop = Encode(stopRow);
            List encodedColumns = EncodeStringList(columns);
            Dictionary encodedAttributes = EncodeAttributes(attributes);
            return client.scannerOpenWithStopTs(tableName, start, stop, encodedColumns, timestamp, encodedAttributes);
        }
        public override List ScannerGetList(int id, int nbRows)
        {
            return client.scannerGetList(id, nbRows);
        }
        public override List ScannerGet(int id)
        {
            return client.scannerGet(id);
        }
        public override List GetRow(string table, string row, Dictionary attributes)
        {
            byte[] tableName = Encode(table);
            byte[] startRow = Encode(row);
            Dictionary encodedAttributes = EncodeAttributes(attributes);
            return client.getRow(tableName, startRow, encodedAttributes);
        }
        public override List GetRows(string table, List rows, Dictionary attributes)
        {
            byte[] tableName = Encode(table);
            List encodedRows = EncodeStringList(rows);
            Dictionary encodedAttributes = EncodeAttributes(attributes);
            return client.getRows(tableName, encodedRows, encodedAttributes);
        }
        public override List GetRowsWithColumns(string table, List rows, List columns, Dictionary attributes)
        {
            byte[] tableName = Encode(table);
            List encodedRows = EncodeStringList(rows);
            List encodedColumns = EncodeStringList(columns);
            Dictionary encodedAttributes = EncodeAttributes(attributes);
            return client.getRowsWithColumns(tableName, encodedRows, encodedColumns, encodedAttributes);
        }
        public override void ScannerClose(int id)
        {
            client.scannerClose(id);
        }
        public override void IterateResults(TRowResult result)
        {
            foreach (KeyValuePair pair in result.Columns)
            {
                Console.WriteLine("\tCol=" + Decode(pair.Key) + ", Value=" + Decode(pair.Value.Value));
            }
        }
        private String Decode(byte[] bs)
        {
            return UTF8Encoding.Default.GetString(bs);
        }
        private byte[] Encode(String str)
        {
            return UTF8Encoding.Default.GetBytes(str);
        }
        private Dictionary EncodeAttributes(Dictionary attributes)
        {
            Dictionary encodedAttributes = new Dictionary();
            foreach (KeyValuePair pair in attributes)
            {
                encodedAttributes.Add(Encode(pair.Key), Encode(pair.Value));
            }
            return encodedAttributes;
        }
        private List EncodeStringList(List strings) 
        {
            List list = new List();
            if (strings != null)
            {
                foreach (String str in strings)
                {
                    list.Add(Encode(str));
                }
            }
            return list;
        }
    }
}

上面代码,给出了基本的实现,接着我们给出测试用例,调用我们实现的客户端操作,与HBase表进行交互。实现的测试用例类如下所示:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace HbaseThrift.HBase.Thrift
{
    class Test
    {
        private readonly AbstractHBaseThriftService client;
        public Test(String host, int port)
        {
            client = new HBaseThriftClient(host, port);
        }
        public Test() : this("master", 9090)
        {
        }
        static String RandomlyBirthday()
        {
            Random r = new Random();
            int year = 1900 + r.Next(100);
            int month = 1 + r.Next(12);
            int date = 1 + r.Next(30);
            return year + "-" + month.ToString().PadLeft(2, '0') + "-" + date.ToString().PadLeft(2, '0');
        }
        static String RandomlyGender()
        {
            Random r = new Random();
            int flag = r.Next(2);
            return flag == 0 ? "M" : "F";
        }
        static String RandomlyUserType()
        {
            Random r = new Random();
            int flag = 1 + r.Next(10);
            return flag.ToString();
        }
        public void Close()
        {
            client.Close();
        }
        public void CaseForUpdate() {
		    bool writeToWal = false;
            Dictionary attributes = new Dictionary(0);
		    string table = SetTable();
		    // put kv pairs
		    for (int i = 0; i 

上面的测试可以实现操作Hbase表数据。另外,在生成的Thrift客户端代码中,Iface中给出了全部的服务接口,可以根据需要来选择,客户端Client实现了与Thrift交互的一些逻辑的处理,通过该类对象可以代理HBase提供的Thrift服务。

参考链接

  • http://wiki.apache.org/hadoop/Hbase/ThriftApi
  • http://svn.apache.org/viewvc/hbase/trunk/hbase-server/src/main/resources/org/apache/hadoop/hbase/thrift/Hbase.thrift?view=markup
  • http://www.cnblogs.com/panfeng412/archive/2012/11/11/hbase-thrift-api-common-issues-summary.html
  • https://github.com/simplegeo/hadoop-hbase/blob/master/src/examples/thrift/DemoClient.java
  • http://thrift.apache.org/tutorial/java/