impala基于CHD,提供针对HDFS,hbase的实时查询，查询语句类似于hive
包括几个组件
Clients:提供Hue, ODBC clients, JDBC clients, and the Impala Shell与impala交互查询
Hive Metastore:保存数据的元数据，让impala知道数据的结构等信息
Cloudera Impala：协调查询在每个datanode上，分发并行查询任务，并将查询返回客户端
HBase and HDFS：存储数据
环境
hadoop-2.0.0-cdh4.1.2
hive-0.9.0-cdh4.1.2
impala利用yum安装
增加yum库
[cloudera-impala]
name=Impala
baseurl=http://archive.cloudera.com/impala/redhat/5/x86_64/impala/1/
gpgkey = http://archive.cloudera.com/impala/redhat/5/x86_64/impala/RPM-GPG-KEY-cloudera
gpgcheck = 1
加至/etc/yum.repos.d目录下
注意cdh与hive及impala需要版本匹配，具体去impala官网去查一下
需要内存比较大,需要64位机器（推荐有点忘了是否支持32位），支持的linux版本也有要求
http://www.cloudera.com/content/cloudera-content/cloudera-docs/Impala/latest/PDF/Installing-and-Using-Impala.pdf
安装CHD4
http://archive.cloudera.com/cdh4/cdh/4/
cdh与hive都可以在这找到
三台机器
master安装 namenode,secondnamenode,ResourceManager, impala-state-store,impala-shell,hive
slave1安装 datanode,nodemanager,impala-server, impala-shell
slave2安装 datanode,nodemanager,impala-server, impala-shell
hadoop配置
在master机器上配置
$HADOOP_HOME/etc/hadoop中的core-site.xml增加
<property>
<name>io.native.lib.available</name>
<value>true</value>
</property>
<property>
<name>fs.default.name</name>
<value>hdfs://master:9000</value>
<description>The name of the default file system.Either theliteral string "local" or a host:port for NDFS.</description>
<final>true</final>
</property>
$HADOOP_HOME/etc/hadoop中的hdfs-site.xml增加
<property>
<name>dfs.namenode.name.dir</name>
<value>file:/home/hadoop/cloudera/hadoop/dfs/name</value>
<description>Determines where on the local filesystem the DFS namenode should store the name table.If this is a comma-delimited list ofdirectories,then name table is replicated in all of the directories,forredundancy.</description>
<final>true</final>
</property>
<property>
<name>dfs.datanode.data.dir</name>
<value>file:/home/hadoop/cloudera/hadoop/dfs/data</value>
<description>Determines where on the local filesystem an DFS datanode should store its blocks.If this is a comma-delimited list ofdirectories,then data will be stored in all named directories,typically ondifferent devices.Directories that do not exist are ignored.
</description>
<final>true</final>
</property>
<property>
<name>dfs.http.address</name>
<value>fca-vm-arch-proxy1:50070</value>
</property>
<property>
<name>dfs.replication</name>
<value>2</value>
</property>
<property>
<name>dfs.secondary.http.address</name>
<value>fca-vm-arch-proxy1:50090</value>
</property>
<property>
<name>dfs.permission</name>
<value>false</value>
</property>
$HADOOP_HOME/etc/hadoop中的mapred-site.xml增加
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
<property>
<name>mapreduce.job.tracker</name>
<value>hdfs://fca-vm-arch-proxy1:9001</value>
<final>true</final>
</property>
<property>
<name>mapreduce.map.memory.mb</name>
<value>1536</value>
</property>
<property>
<name>mapreduce.map.java.opts</name>
<value>-Xmx1024M</value>
</property>
<property>
<name>mapreduce.reduce.memory.mb</name>
<value>3072</value>
</property>
<property>
<name>mapreduce.reduce.java.opts</name>
<value>-Xmx2560M</value>
</property>
<property>
<name>mapreduce.task.io.sort.mb</name>
<value>512</value>
</property>
<property>
<name>mapreduce.task.io.sort.factor</name>
<value>100</value>
</property>
<property>
<name>mapreduce.reduce.shuffle.parallelcopies</name>
<value>50</value>
</property>
$HADOOP_HOME/etc/hadoop/hadoop-env.sh增加
export JAVA_HOME=/jdk1.6.0_22
系统环境变量
$HOME/.bash_profile增加
export JAVA_HOME=/jdk1.6.0_22
export JAVA_BIN=${JAVA_HOME}/bin
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
export HADOOP_HOME=/home/hadoop/cloudera/hadoop-2.0.0-cdh4.1.2
export HADOOP_MAPRED_HOME=${HADOOP_HOME}
export HADOOP_COMMON_HOME=${HADOOP_HOME}
export HADOOP_HDFS_HOME=${HADOOP_HOME}
export HADOOP_YARN_HOME=${HADOOP_HOME}
export PATH=$PATH:${JAVA_HOME}/bin:${HADOOP_HOME}/bin:${HADOOP_HOME}/sbin:${HIVE_HOME}/bin
export JAVA_HOME JAVA_BIN PATH CLASSPATH JAVA_OPTS
export HADOOP_LIB=${HADOOP_HOME}/lib
export HADOOP_CONF_DIR=${HADOOP_HOME}/etc/hadoop
source $HOME/.bash_profile使变量生效
yarn配置
$HADOOP_HOME/etc/hadoop/yarn-site.xml中增加
<property>
<name>yarn.resourcemanager.address</name>
<value>fca-vm-arch-proxy1:9002</value>
</property>
<property>
<name>yarn.resourcemanager.scheduler.address</name>
<value>fca-vm-arch-proxy1:9003</value>
</property>
<property>
<name>yarn.resourcemanager.resource-tracker.address</name>
<value>fca-vm-arch-proxy1:9004</value>
</property>
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce.shuffle</value>
</property>
<property>
<name>yarn.nodemanager.aux-services.mapreduce.shuffle.class</name>
<value>org.apache.hadoop.mapred.ShuffleHandler</value>
</property>
$HADOOP_HOME/etc/hadoop/slaves增加
slave1
slave2
将master上的CHD目录及.bash_profile拷贝到slave1,slave2，并配置环境变量，并且配置好ssh无密码登陆，网上很多不详细说了
启动hdfs和yarn
以上步骤都执行完成后，用hadoop用户登录到master机器依次执行：
hdfs namenode -format
start-dfs.sh
start-yarn.sh
通过jps命令查看：
master成功启动了NameNode、ResourceManager、SecondaryNameNode进程；
slave1,slave2成功启动了DataNode、NodeManager进程。
hive安装
hive只需要在master上安装因为impala-state-store需要hive读取元数据，hive又依赖于关系统型数据库（mysql)所以安装mysql
下载hive
http://archive.cloudera.com/cdh4/cdh/4/
解压缩hive
$HOME/.bash_profile增加
export HIVE_HOME=/home/hadoop/hive-0.9.0-cdh4.1.2
export PATH=$PATH:${JAVA_HOME}/bin:${HADOOP_HOME}/bin:${HADOOP_HOME}/sbin:${HIVE_HOME}/bin
export HIVE_CONF_DIR=$HIVE_HOME/conf
export HIVE_LIB=$HIVE_HOME/lib
source $HOME/.bash_profile使环境变量生效
在hive/lib目录下加入mysql-connector-java-5.1.8.jar
$HIVE_HOME/conf/hive.site.xml增加
<property>
<name>hive.metastore.uris</name>
<value>thrift://master:9083</value>
<description>Thrift uri for the remote metastore. Used by metastore client to connect to remote metastore.</description>
</property>
<property>
<name>hive.metastore.local</name>
<value>false</value>
</property>
<property>
<name>javax.jdo.option.ConnectionURL</name>
<value>jdbc:mysql://master:3306/hive?createDatabaseIfNoExist=true</value>
<description>JDBC connect string for a JDBC metastore</description>
</property>
<property>
<name>javax.jdo.option.ConnectionDriverName</name>
<value>com.mysql.jdbc.Driver</value>
<description>Driver class name for a JDBC metastore</description>
</property>
<property>
<name>javax.jdo.option.ConnectionUserName</name>
<value>root</value>
<description>username to use against metastore database</description>
</property>
<property>
<name>javax.jdo.option.ConnectionPassword</name>
<value>password</value>
<description>password to use against metastore database</description>
</property>
<property>
<name>hive.security.authorization.enabled</name>
<value>false</value>
<description>enable or disable the hive client authorization</description>
</property>
<property>
<name>hive.security.authorization.createtable.owner.grants</name>
<value>ALL</value>
<description>the privileges automatically granted to the owner whenever a table gets created.
An example like "select,drop" will grant select and drop privilege to the owner of the table</description>
</property>
<property>
<name>hive.querylog.location</name>
<value>${user.home}/hive-logs/querylog</value>
</property>
由于hive metstore我们是安装在远程节点上的所以hive.metastore.local是false
hive.metastore.uris设置远程连接metstore
验证成功状态
完成以上步骤之后，验证hive安装是否成功
在master命令行执行hive，并输入”show tables;”，出现以下提示，说明hive安装成功：
>hive
hive> show databases;
ok
Time taken: 18.952 seconds
impala安装
master上安装 impala-state-store
sudo yum install impala-state-store
master上安装 impala-shell
sudo yum install impala-shell
配置impala
修改/etc/default/impala
IMPALA_STATE_STORE_HOST=192.168.200.114
IMPALA_STATE_STORE_PORT=24000
IMPALA_BACKEND_PORT=22000
IMPALA_LOG_DIR=/var/log/impala
IMPALA_STATE_STORE_ARGS=" -log_dir=${IMPALA_LOG_DIR} -state_store_port=${IMPALA_STATE_STORE_PORT}"
IMPALA_SERVER_ARGS="
-log_dir=${IMPALA_LOG_DIR}
-state_store_port=${IMPALA_STATE_STORE_PORT}
-use_statestore
-state_store_host=${IMPALA_STATE_STORE_HOST}
-be_port=${IMPALA_BACKEND_PORT}"
ENABLE_CORE_DUMPS=false
LIBHDFS_OPTS=-Djava.library.path=/usr/lib/impala/lib
MYSQL_CONNECTOR_JAR=/home/hadoop/cloudera/hive/hive-0.9.0-cdh4.1.2/lib/mysql-connector-java-5.1.8.jar
IMPALA_BIN=/usr/lib/impala/sbin
IMPALA_HOME=/usr/lib/impala
HIVE_HOME=/home/hadoop/cloudera/hive/hive-0.9.0-cdh4.1.2
# HBASE_HOME=/usr/lib/hbase
IMPALA_CONF_DIR=/usr/lib/impala/conf
HADOOP_CONF_DIR=/usr/lib/impala/conf
HIVE_CONF_DIR=/usr/lib/impala/conf
# HBASE_CONF_DIR=/etc/impala/conf
拷贝hadoop的core-site.xml,hdfs-site.xml，hive的hive-site.xml到/usr/lib/impala/conf中
core-site.xml增加
<property>
<name>dfs.client.read.shortcircuit</name>
<value>true</value>
</property>
<property>
<name>dfs.client.read.shortcircuit.skip.checksum</name>
<value>false</value>
</property>
hdfs-site.xml增加,hadoop的hdfs-site.xml也增加
<property>
<name>dfs.datanode.hdfs-blocks-metadata.enabled</name>
<value>true</value>
</property>
<property>
<name>dfs.datanode.data.dir.perm</name>
<value>750</value>
</property>
<property>
<name>dfs.block.local-path-access.user</name>
<value>hadoop</value>
</property>
<property>
<name>dfs.client.read.shortcircuit</name>
<value>true</value>
</property>
<property>
<name>dfs.client.file-block-storage-locations.timeout</name>
<value>3000</value>
</property>
<property>
<name>dfs.client.use.legacy.blockreader.local</name>
<value>true</value>
</property>
拷贝mysql-connector-java-5.1.8.jar到/usr/lib/impala/lib下
拷贝mysql-connector-java-5.1.8.jar到/var/lib/impala下
拷贝/usr/lib/impala/lib/*.so*到$HADOOP_HOME/lib/native/
slave1,slave2上安装
sudo yum install impala
sudo yum install impala-server
sudo yum install impala-shell
master上的hive-site.xml,core-site.xml,hdfs-site.xml拷贝到slaver1,slaver2上，jar的拷贝与master一致
启动hive metastore
在master上执行hive --service metastore
启动impala statestore
在master上执行statestored -log_dir=/var/log/impala -state_store_port=24000
在slave1,slave2上启动impalad
sudo /etc/init.d/impala-server start
impala查看/var/log/impala/statestored.INFO是否成功 statestored.ERROR查看错误
注意先要在master启动hive metastore,impala statesored,再在slave1,slave2启动impalad-server
测试是否成功
master上执行
impala-shell
[Not connected] >connect slave1;
[slave1:21000] > use hive;
Query: use hive
[slave1:21000] >show tables;
ok
没有错误说成功
如果在slave1上插入数据需要在slave2上refresh 表名才能同步数据，而不是网上说的refresh,后面必须加表名。
如果不是shell执行操作，应该可以同步数据，没测试过。
注意事项
impala在插入数据时可以会出错
hdfsOpenFile(hdfs://fmaster:9000/user/hive/warehouse/test/.2038125373027453036......
是权限问题，因为我们是用sudo (root用户)启动的impala但是test表hadoop用户有增删改查的权限，但是root没有
解决方法
hdfs dfs -chmod -R 777 /user/hive/warehouse/test