Hadoop支持Lzo压缩配置及flume采集案例

一、hadoop支持Lzo压缩配置

1）hadoop本身并不支持lzo压缩，故需要使用twitter提供的hadoop-lzo开源组件。hadoop-lzo需依赖hadoop和lzo进行编译，编译步骤如下。
2）将编译好后的hadoop-lzo-0.4.20.jar 放入hadoop-2.7.2/share/hadoop/common/

[atone@hadoop102 common]$ pwd
/opt/module/hadoop-2.7.2/share/hadoop/common
[atone@hadoop102 common]$ ls
hadoop-lzo-0.4.20.jar

3）同步hadoop-lzo-0.4.20.jar到hadoop103、hadoop104

[atone@hadoop102 common]$ xsync hadoop-lzo-0.4.20.jar

4）core-site.xml增加配置支持LZO压缩

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>

<configuration>
<property>
<name>io.compression.codecs</name>
<value>
org.apache.hadoop.io.compress.GzipCodec,
org.apache.hadoop.io.compress.DefaultCodec,
org.apache.hadoop.io.compress.BZip2Codec,
org.apache.hadoop.io.compress.SnappyCodec,
com.hadoop.compression.lzo.LzoCodec,
com.hadoop.compression.lzo.LzopCodec
</value>
</property>

<property>
<name>io.compression.codec.lzo.class</name>
<value>com.hadoop.compression.lzo.LzoCodec</value>
</property>
</configuration>

5）同步core-site.xml到hadoop103、hadoop104

[atone@hadoop102 hadoop]$ xsync core-site.xml

6）启动及查看集群

[atone@hadoop102 hadoop-2.7.2]$ sbin/start-dfs.sh
[atone@hadoop103 hadoop-2.7.2]$ sbin/start-yarn.sh

7）创建lzo文件的索引，lzo压缩文件的可切片特性依赖于其索引，故我们需要手动为lzo压缩文件创建索引。若无索引，则整个lzo文件的切片只有一个。

    使用的是hadoop-lzo依赖中的工具类来为lzo压缩文件创建索引，索引文件与压缩文件在同一路径下，后缀名为.lzo.index；

示例命令：

hadoop jar 
/home/pirate/programs/hadoop/share/hadoop/common/hadoop-lzo-0.4.20.jar 
com.hadoop.compression.lzo.DistributedLzoIndexer 
/user/pirate/flume/hmtft/MoneyFlow_Test/

参考：

Hive之配置和使用LZO压缩

Linux中编译hadoop-lzo使hadoop能够支持lzo

二、配置Hive支持lzo

在$HIVE_HOME/conf/hive-site.xml文件中设置如下参数，使得Hive进行查询时使用压缩功能，具体使用的压缩算法默认与Hadoop中的配置相同，当然也有相应的参数可以进行覆盖：

<!-- 设置hive语句执行输出文件是否开启压缩,具体的压缩算法和压缩格式取决于hadoop中
设置的相关参数 -->
<!-- 默认值:false -->
<property>
<name>hive.exec.compress.output</name>
<value>true</value>
<description>
This controls whether the final outputs of a query (to a local/HDFS file or a Hive table)
is compressed.
The compression codec and other options are determined from Hadoop config variables
mapred.output.compress*
</description>
</property>
<!-- 控制多个MR Job的中间结果文件是否启用压缩,具体的压缩算法和压缩格式取决于hadoop中
设置的相关参数 -->
<!-- 默认值:false -->
<property>
<name>hive.exec.compress.intermediate</name>
<value>true</value>
<description>
This controls whether intermediate files produced by Hive between multiple map-reduce jobs are compressed.
The compression codec and other options are determined from Hadoop config variables mapred.output.compress*
</description>
</property>

3.oozie支持lzo 

应该把oozie引用的hive-site.xml更新到集群即可（待测。。）

4.Flume采集到HDFS采用lzo压缩：

注：需要把hadoop相关配置文件copy到flume/conf下

project.sources= log-type 
project.channels= log-type 
project.sinks= log-type 

#source
project.sources.log-type.type = org.apache.flume.source.kafka.KafkaSource
project.sources.log-type.batchSize = 500000
project.sources.log-type.batchDurationMillis = 300000
project.sources.log-type.kafka.bootstrap.servers = kafka0:9092,kafka1:9092,kafka2:9092
project.sources.log-type.kafka.topics = project-udplog-log-type
project.sources.log-type.kafka.consumer.group.id = project-udplog-log-type-t4
project.sources.log-type.kafka.consumer.auto.offset.reset = earliest


## channel 
project.channels.log-type.type = memory
#project.channels.log-type.checkpointDir = /home/pirate/programs/flume/checkpoint/project/log-type
#project.channels.log-type.dataDirs = /home/pirate/programs/flume/data/project/log-type/
#project.channels.log-type.maxFileSize = 2146435071
project.channels.log-type.capacity = 1000000
project.channels.log-type.transactionCapacity = 1000000
project.channels.log-type.keep-alive = 60



## sinlog-type
project.sinks.log-type.type = hdfs
project.sinks.log-type.hdfs.path = hdfs://mycluster/user/pirate/flume/project/Log-Type/ds=%Y-%m-%d/hs=%H/
project.sinks.log-type.hdfs.batchSize = 500000

#project.sinks.log-type.hdfs.fileType = DataStream
project.sinks.log-type.hdfs.callTimeout=60000
project.sinks.log-type.hdfs.threadsPoolSize = 100
project.sinks.log-type.hdfs.codeC = lzop  # 注意：1.这里用 lzop；否则：创建 hive 外部分区表映射到相关路径，无法查询数据（待测） 2.也可以直接指定为snappy压缩，hive建表映射不需要更改，文本格式就能读取到
project.sinks.log-type.hdfs.fileType = CompressedStream #开启压缩


## 
project.sources.log-type.channels = log-type 
project.sinks.log-type.channel= log-type
project.sinks.log-type.hdfs.minBlockReplicas=1

启动：

nohup /home/atone/programs/flume/bin/flume-ng agent -n project 
-c $flume/conf/ 
-f /home/atone/programs/flume/job/test-snappy.conf 
-Dflume.monitoring.type=http -Dflume.monitoring.port=34550 
-Dflume.root.logger=WARN,LOGFILE -Dflume.log.file=./test_flume_log.log 2>&1 &

结果示例：