Cloudera manager安裝impala除了第一篇文章提到的條件：1.需要安裝centos6.2系統。2.CDH4.1.0以上版本3.要在叢集每個節點安裝hive。4.hive的元資料庫要使用mysql。5.每臺主機hosts檔案中都加入所有機器的IP地址和主機名的對應關係。還需要關閉ipv6.否則cloudera manager無法最終識別主機。

關閉ipv6後，登陸cloudera manager頁面顯示有三臺管理的主機。OK，cloudera manager已經工作正常。點選‘服務’選項，選擇角色分配，為每一臺主機分配角色。Impala不在初始的服務內，等所有服務啟動正常後，需要再新增impala

$ time impala-shell - -impalad=200.200.200.11:21000 –q ‘select * from tt’

主機地址測試表

$ time hive –e ‘selcet * from tt’

進行比較時間。一個簡單的比較結果如下：

Impala

time impala-shell --impalad=200.200.200.11:21000 -q'select id from tt'

real   0m4.921s

user   0m0.072s

sys    0m0.042s

hive

time hive -e 'select id from tt'

Logging initialized using configuration in file:/etc/hive/conf.dist/hive-log4j.properties

Hive history file=/tmp/hdfs/hive_job_log_hdfs_201212111430_946199434.txt

Total MapReduce jobs = 1

Launching Job 1 out of 1

Number of reduce tasks is set to 0 since there's no reduce operator

Starting Job = job_201212111359_0001, Tracking URL = http://big1-1:50030/jobdetails.jsp?jobid=job_201212111359_0001

Kill Command = /usr/lib/hadoop/bin/hadoop job  -Dmapred.job.tracker=big1-1:8021 -kill job_201212111359_0001

Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 0

2012-12-11 14:30:44,633 Stage-1 map = 0%,  reduce = 0%

2012-12-11 14:30:49,716 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.92 sec

2012-12-11 14:30:50,735 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.92 sec

2012-12-11 14:30:51,746 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.92 sec

2012-12-11 14:30:52,761 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 0.92 sec

MapReduce Total cumulative CPU time: 920 msec

Ended Job = job_201212111359_0001

MapReduce Jobs Launched:

Job 0: Map: 1   Cumulative CPU: 0.92 sec   HDFS Read: 0 HDFS Write: 0 SUCCESS

Total MapReduce CPU Time Spent: 920 msec

OK

Time taken: 36.364 seconds

real   0m40.248s

user   0m15.590s

sys    0m2.638s

可以看出impala比hive快很多。