Flume连接HDFS和Hive

Flume连接HDFS

进入Flume配置
配置flume.conf

 # Name the components on this agent
 a1.sources = r1
 a1.sinks = k1
 a1.channels = c1

 # sources
 a1.sources.r1.type = netcat
 a1.sources.r1.bind = 0.0.0.0
 a1.sources.r1.port = 41414

 # sinks
 a1.sinks.k1.type = hdfs
 a1.sinks.k1.hdfs.path = hdfs://slave1/flume/events/%y-%m-%d/%H%M/%S
 a1.sinks.k1.hdfs.filePrefix = events-
 a1.sinks.k1.hdfs.round = true
 a1.sinks.k1.hdfs.roundValue = 10
 a1.sinks.k1.hdfs.roundUnit = minute
 a1.sinks.k1.hdfs.useLocalTimeStamp=true
 a1.sinks.k1.hdfs.batchSize = 10
 a1.sinks.k1.hdfs.fileType = DataStream

 # channels
 a1.channels.c1.type = memory
 a1.channels.c1.capacity = 1000
 a1.channels.c1.transactionCapacity = 100

 # Bind the source and sink to the channel
 a1.sources.r1.channels = c1
 a1.sinks.k1.channel = c1

测试telnet通信

telnet slave1 41414

查看日志找到HDFS文件
查看文件内容，测试成功

Windows下Flume连接Hive

 # Name the components on this agent
a1.sources=r1
a1.sinks=k1
a1.channels=c1

# source
a1.sources.r1.type=avro
a1.sources.r1.bind=0.0.0.0
a1.sources.r1.port=43434

 # sink
a1.sinks.k1.type = hive
a1.sinks.k1.hive.metastore = thrift://192.168.18.33:9083
a1.sinks.k1.hive.database = bd14
a1.sinks.k1.hive.table = flume_log
a1.sinks.k1.useLocalTimeStamp = true
a1.sinks.k1.serializer = DELIMITED
a1.sinks.k1.serializer.delimiter = "\t"
a1.sinks.k1.serializer.serdeSeparator = '\t'
a1.sinks.k1.serializer.fieldnames = id,time,context
a1.sinks.k1.hive.txnsPerBatchAsk = 5

 # channel
a1.channels.c1.type=memory
a1.channels.c1.capacity=1000
a1.channels.c1.transactionCapacity=100

 # Bind the source and sink to the channel
a1.sources.r1.channels=c1
a1.sinks.k1.channel=c1

配置Windows下的flume

 # Name the components on this agent
 a1.sources = r1
 a1.sinks = k1
 a1.channels = c1

 # source
 a1.sources.r1.type = spooldir
 a1.sources.r1.spoolDir = F:\\test
 a1.sources.r1.fileHeader = true

 # sink
 a1.sinks.k1.type = avro
 a1.sinks.k1.hostname = 192.168.18.34
 a1.sinks.k1.port = 43434

 # channel
 a1.channels.c1.type = memory
 a1.channels.c1.capacity = 1000
 a1.channels.c1.transactionCapacity = 100

 # Bind the source and sink to the channel
 a1.sources.r1.channels = c1
 a1.sinks.k1.channel = c1

在hive中创建日志表

在flume文档中要求将hive表分桶以及设置为orc格式，测试不声明orc格式，Hive将不会收到数据

create table flume_log(
id int
,time string
,context string
)
clustered by (id) into 3 buckets
stored as orc;

创建日志文件到监控目录F:\test
在Windows中 flume的bin目录下启动flume

flume-ng.cmd agent -conf-file ../conf/windows.conf -name a1 -property flume.root.logger=INFO,console

在Windows中查找一个log文件拖放到F:\test中，内容如下
当flume读取完文件后，文件后缀会增加completed
查看Hive表
测试成功，本来是想通过impala查询Hive表，但Impala不支持orc格式的Hive表，而flume中sink端需要采用orc格式传输数据，所以只能放弃impala，后续解决问题再进行补充

三、遇到问题

Flume无法连接到HDFS
解决：a1.sinks.k1.hdfs.path = hdfs://slave1:9000/flume/events/%y-%m-%d/%H%M/%S
改为 a1.sinks.k1.hdfs.path = hdfs://slave1/flume/events/%y-%m-%d/%H%M/%S

原因：在CDH的Flume中，设置路径只需要IP地址，不需要配置端口

HDFS文件存在乱码

解决：在flume配置中添加

a1.sinks.k1.hdfs.fileType = DataStream

原因：
hdfs.fileType默认为SequenceFile，会压缩文件

AvroRuntimeException: Excessively large list allocation request detected: 825373449 items!

解决：调整flume中java堆栈大小
原因：Flume内存溢出
NoClassDefFoundError: org/apache/hive/hcatalog/streaming/RecordWriter

解决：
找到Hive的jar包所在目录

找到Flume的jar包所在目录

cp /opt/cloudera/parcels/CDH-5.11.1-1.cdh5.11.1.p0.4/jars/hive-* /opt/cloudera/parcels/CDH-5.11.1-1.cdh5.11.1.p0.4/lib/flume-ng/lib/

原因：flume缺少了hive的jar包，需要从CDH拷贝

EventDeliveryException: java.lang.NullPointerException: Expected timestamp in the Flume event headers, but it was null

原因：时间戳参数设置错误
解决：
在flume的conf文件中配置sink端

a1.sinks.k1.hive.useLocalTimeStamp=true

参考文章：
https://blog.csdn.net/lifuxiangcaohui/article/details/49949865
https://blog.csdn.net/panguoyuan/article/details/39555239
http://miximixi.me/index.php/archives/961