Hadoop2.7.1+Hbase1.2.1集群环境搭建(6)snappy安装

(1)hadoop2.7.1源码编译	http://aperise.iteye.com/blog/2246856
(2)hadoop2.7.1安装准备	http://aperise.iteye.com/blog/2253544
(3)1.x和2.x都支持的集群安装	http://aperise.iteye.com/blog/2245547
(4)hbase安装准备	http://aperise.iteye.com/blog/2254451
(5)hbase安装	http://aperise.iteye.com/blog/2254460
(6)snappy安装	http://aperise.iteye.com/blog/2254487
(7)hbase性能优化	http://aperise.iteye.com/blog/2282670
(8)雅虎YCSBC测试hbase性能测试	http://aperise.iteye.com/blog/2248863
(9)spring-hadoop实战	http://aperise.iteye.com/blog/2254491
(10)基于ZK的Hadoop HA集群安装	http://aperise.iteye.com/blog/2305809

 

     lzo   snappy   gzip是hadoop支持的三种压缩方式，目前网上推荐snappy，这里讲解如何安装snappy

 

1.在linux上安装snappy压缩库

#1.去https://github.com/google/snappy/releases下载snappy-1.1.3.tar.gz并解压
cd /root
wget https://github.com/google/snappy/releases/download/1.1.3/snappy-1.1.3.tar.gz
tar -zxvf snappy-1.1.3.tar.gz

#2.在linux上编译安装
cd /root/snappy-1.1.3
./configure
make
make install

#3.默认安装在/usr/local/lib,安装成功后文件如下：

    github上Hadoop源码(https://github.com/apache/hadoop/blob/trunk/BUILDING.txt)推荐的安装方式为：sudo apt-get install snappy libsnappy-dev

 

 2.编译Hadoop2.7.1源码中模块hadoop-common

        当前Hadoop新的版本在模块hadoop-common中都已经集成了相关压缩库的编解码工具，无需去其它地方下载编解码打包：

snappy	https://github.com/apache/hadoop/blob/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/SnappyCodec.java  自带，需要Linux已经安装snappy库
默认编解码	https://github.com/apache/hadoop/blob/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/DefaultCodec.java  自带
gzip	https://github.com/apache/hadoop/blob/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/GzipCodec.java  自带
bzip2	https://github.com/apache/hadoop/blob/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/BZip2Codec.java  自带
lz4	https://github.com/apache/hadoop/blob/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/Lz4Codec.java  自带
lzo	Hadoop源代码里不含有编解码代码，可在https://github.com/twitter/hadoop-lzo找到相关编解码

        如果之前编译过Hadoop源代码，这一步骤可以不做。

        官网给定的安装包中是不支持snappy压缩的，需要自己重新编译Hadoop源码，而编译源码首先需要保证linux上已经安装了linux关于snappy的库，已经在步骤1中解决。

        关于如何编译Hadoop源代码，请参见http://aperise.iteye.com/blog/2246856

        1.下载hadoop源代码hadoop-2.7.1-src.tar.gz放置于/root下并解压缩 

cd /root
wget http://www.apache.org/dyn/closer.cgi/hadoop/common/hadoop-2.7.1/hadoop-2.7.1-src.tar.gz
tar -zxvf hadoop-2.7.1-src.tar.gz  

        2.准备Hadoop编译必备环境，请参见http://aperise.iteye.com/blog/2246856 

        3.单独编译打包hadoop-common，获取对于snappy压缩的支持(如果想编译整个工程请参见http://aperise.iteye.com/blog/2246856) 

cd /root/hadoop-2.7.1-src
export MAVEN_OPTS="-Xms256m -Xmx512m"
mvn package -Pdist,native -DskipTests -Dtar -rf :hadoop-common -Drequire.snappy -X
#如果想编译整个代码且单独指定snappy库位置，命令如下：
#mvn package -Pdist,native,docs,src -DskipTests -Drequire.snappy -Dsnappy.lib=/usr/local/lib  

        4.编译完成后，在/root/hadoop-2.7.1-src/hadoop-dist/target/hadoop-2.7.1/lib/native下得到如下文件：

        5.编译完成后，在/root/hadoop-2.7.1-src/hadoop-dist/target/hadoop-2.7.1/share/hadoop/common下得到如下文件：

  

3.hadooo中添加snappy支持

#1.将步骤2中编译的snappy支持文件拷贝到Hadoop中
#这里我安装的Hadoop位置为/home/hadoop/hadoop-2.7.1
cp -r /root/hadoop-2.7.1-src/hadoop-dist/target/hadoop-2.7.1/lib/native/* /home/hadoop/hadoop-2.7.1/lib/native/
cp /usr/local/lib/* /home/hadoop/hadoop-2.7.1/lib/native/

#2.将步骤3编译后的hadoop-common-2.7.1.jar文件拷贝到Hadoop
#这里我安装的Hadoop位置为/home/hadoop/hadoop-2.7.1
cp -r /root/hadoop-2.7.1-src/hadoop-dist/target/hadoop-2.7.1/share/hadoop/common/* /home/hadoop/hadoop-2.7.1/share/hadoop/common/ 

#3.修改hadoop的配置文件/home/hadoop/hadoop-2.7.1/etc/hadoop/core-site.xml,增加如下配置：
<property>  
  <name>io.compression.codecs</name>  
  <value>  
  org.apache.hadoop.io.compress.DefaultCodec,  
  org.apache.hadoop.io.compress.GzipCodec,  
  org.apache.hadoop.io.compress.BZip2Codec,   
  org.apache.hadoop.io.compress.Lz4Codec,  
  org.apache.hadoop.io.compress.SnappyCodec  
  </value>  
  <description>A comma-separated list of the compression codec classes that can  
  be used for compression/decompression. In addition to any classes specified  
  with this property (which take precedence), codec classes on the classpath  
  are discovered using a Java ServiceLoader.</description>  
</property> 

#4.修改/home/hadoop/hadoop-2.7.1/etc/hadoop/mapred-site.xml,添加如下内容：
<property>    
  <name>mapreduce.output.fileoutputformat.compress</name>    
  <value>true</value>    
  <description>Should the job outputs be compressed?    
  </description>    
</property>    
<property>    
  <name>mapreduce.output.fileoutputformat.compress.type</name>    
  <value>RECORD</value>    
  <description>If the job outputs are to compressed as SequenceFiles, how should    
               they be compressed? Should be one of NONE, RECORD or BLOCK.    
  </description>    
</property>    
<property>    
  <name>mapreduce.output.fileoutputformat.compress.codec</name>    
  <value>org.apache.hadoop.io.compress.SnappyCodec</value>    
  <description>If the job outputs are compressed, how should they be compressed?    
  </description>    
</property>    
<property>    
  <name>mapreduce.map.output.compress</name>    
  <value>true</value>    
  <description>Should the outputs of the maps be compressed before being    
               sent across the network. Uses SequenceFile compression.    
  </description>    
</property>    
<property>    
  <name>mapreduce.map.output.compress.codec</name>    
  <value>org.apache.hadoop.io.compress.SnappyCodec</value>    
  <description>If the map outputs are compressed, how should they be     
               compressed?    
  </description>    
</property>   

    至此，Hadoop中已经可以支持snappy压缩算法了，hbase目前还待配置，请往下看。

 

4.hbase中添加snappy支持

#1.在hbase中创建放置Hadoop对于本地库支持的文件目录
mkdir -p /home/hadoop/hbase-1.2.1/lib/native/Linux-amd64-64

#2.拷贝Hadoop中所有本地库支持到hbase中
cp -r /home/hadoop/hadoop2.7.1/lib/native/* /home/hadoop/hbase-1.2.1/lib/native/Linux-amd64-64/

         至此，hbase中已经添加了对于snappy的支持。

 

5.在hbase中测试snappy

cd /home/hadoop/hbase-1.2.1/bin/
./hbase org.apache.hadoop.hbase.util.CompressionTest hdfs://hadoop-ha-cluster/hbase/data/default/signal/3a194dcd996fd03c0c26bf3d175caaec/info/0c7f62f10a4c4e548c5ff1c583b0bdfa snappy  

      上面hdfs://hadoop-ha-cluster/hbase/data/default/signal/3a194dcd996fd03c0c26bf3d175caaec/info/0c7f62f10a4c4e548c5ff1c583b0bdfa是存在于我Hadoop上的HDFS文件

 

     

6.HDFS中如何查看压缩格式为snappy的文件

 

        hdfs dfs -text /aaa.snappy