Cloudera's Distribution Including Apache Hadoop (CDH) is one of the Hadoop distributions. Hadoop 3.0.0 in CDH 6.0.1 supports OSS. This topic describes how to enable CDH 6 components such as Hadoop, Hive, Spark, and Impala to query OSS data.
Prerequisites
Step 1: Add OSS configurations
- Use cluster management tool CM to add configurations.
If no clusters are managed by CM, modify the core-site.xml file. The following table uses CM as an example to describe the configurations to be added.
For more information about parameter descriptions, visit Hadoop-Aliyun module.Configuration item Configuration method fs.oss.endpoint Enter the endpoint used to access the region where the bucket is located. Example: oss-cn-zhangjiakou-internal.aliyuncs.com.
fs.oss.accessKeyId Enter the AccessKey ID used to access OSS. fs.oss.accessKeySecret Enter the AccessKey secret used to access OSS. fs.oss.impl Enter the class used to implement the OSS file system through Hadoop. Set the value to org.apache.hadoop.fs.aliyun.oss.AliyunOSSFileSystem. fs.oss.buffer.dir Enter the temporary file directory. We recommend that you set this parameter to /tmp/oss.
fs.oss.connection.secure.enabled Specify whether to enable HTTPS. Performance may be affected when HTTPS is enabled. We recommend that you set this parameter to false.
fs.oss.connection.maximum Enter the maximum number of connections to OSS. We recommend that you set this parameter to 2048.
- Restart the cluster as prompted by CM.
- Test reads and writes on OSS data
- Test data reading from OSS:
hadoop fs -ls oss://${your-bucket-name}/ - Test data writing to OSS:
hadoop fs -mkdir oss://${your-bucket-name}/hadoop-testIf data can be read from and written to OSS, the configurations are successful. Otherwise, check configurations.
Note All content in ${} is environment variables. Modify these environment variables as needed.
- Test data reading from OSS:
Step 2: Configure OSS support for Impala
By default, CDH 6 supports OSS. However the OSS-compliant package is not included in CLASSPATH of the Impala component. To add this package to CLASSPATH, perform the following operations on all Impala nodes:
- Go to the ${CDH_HOME}/lib/impala directory. Create a symbolic link:
[root@cdh-master impala]# cd lib/ [root@cdh-master lib]# ln -s .. /.. /../jars/hadoop-aliyun-3.0.0-cdh6.0.1.jar hadoop-aliyun.jar [root@cdh-master lib]# ln -s .. /.. /../jars/aliyun-sdk-oss-2.8.3.jar aliyun-sdk-oss-2.8.3.jar [root@cdh-master lib]# ln -s .. /.. /../jars/jdom-1.1.jar jdom-1.1.jar - Go to the ${CDH_HOME}/bin directory, modify the impalad, statestored, and catalogd files. In the last line of each file, add the following content to the front of the
exec command:
export CLASSPATH=${CLASSPATH}:${IMPALA_HOME}/lib/hadoop-aliyun.jar:${IMPALA_HOME}/lib/aliyun-sdk-oss-2.8.3.jar:${IMPALA_HOME}/lib/jdom-1.1.jar - Restart Impala-related processes on all nodes.
Verify the configurations
Use Impala to query OSS data. Run query statements derived from TPC-DS. For more information, visit Apache Impala and TPC-DS queries in hive-testbench.
TPC-DS is based on HiveQL, which is compatible with Impala SQL. For compatibility reasons, this topic uses HiveQL as an example.
- Generate sample data and store it in OSS.
[root@cdh-master ~]# git clone https://github.com/hortonworks/hive-testbench.git [root@cdh-master ~]# cd hive-testbench [root@cdh-master hive-testbench]# git checkout hive14 [root@cdh-master hive-testbench]# ./tpcds-build.sh [root@cdh-master hive-testbench]# FORMAT=textfile ./tpcds-setup.sh 50 oss://{your-bucket-name}/ - Create a table.
The statement used to create a table by using the TPC-DS benchmark is compatible with that by using Impala. Copy the statement in the ddl-tpcds/text/alltables.sql file. Modify ${LOCATION}. Example:
[root@cdh-master hive-testbench]# impala-shell -i cdh-slave01 -d default Starting Impala Shell without Kerberos authentication Connected to cdh-slave01:21000 Server version: impalad version 3.0.0-cdh6.0.1 RELEASE(build9a74a5053de5f7b8dd983802e6d75e58d31472db) *********************************************************************************** Welcome to the Impala shell. (Impala Shell v3.0.0-cdh6.0.1(9a74a50) built on Wed Sep 1911:27:37 PDT 2018) Want to know what version of Impala you're connected to? Run the VERSION command to find out! *********************************************************************************** Query: use `default` [cdh-slave01:21000] default> create external table call_center( > cc_call_center_sk bigint > , cc_call_center_id string > , cc_rec_start_date string > , cc_rec_end_date string > , cc_closed_date_sk bigint > , cc_open_date_sk bigint > , cc_name string > , cc_class string > , cc_employees int > , cc_sq_ft int > , cc_hours string > , cc_manager string > , cc_mkt_id int > , cc_mkt_class string > , cc_mkt_desc string > , cc_market_manager string > , cc_division int > , cc_division_name string > , cc_company int > , cc_company_name string > , cc_street_number string > , cc_street_name string > , cc_street_type string > , cc_suite_number string > , cc_city string > , cc_county string > , cc_state string > , cc_zip string > , cc_country string > , cc_gmt_offset double > , cc_tax_percentage double > ) > row format delimited fields terminated by '|' > location 'oss://{your-bucket-name}/50/call_center'; Query: create external table call_center( cc_call_center_sk bigint , cc_call_center_id string , cc_rec_start_date string , cc_rec_end_date string , cc_closed_date_sk bigint , cc_open_date_sk bigint , cc_name string , cc_class string , cc_employees int , cc_sq_ft int , cc_hours string , cc_manager string , cc_mkt_id int , cc_mkt_class string , cc_mkt_desc string , cc_market_manager string , cc_division int , cc_division_name string , cc_company int , cc_company_name string , cc_street_number string , cc_street_name string , cc_street_type string , cc_suite_number string , cc_city string , cc_county string , cc_state string , cc_zip string , cc_country string , cc_gmt_offset double , cc_tax_percentage double ) row format delimited fields terminated by '|' location 'oss://{your-bucket-name}/50/call_center' +-------------------------+ | summary | +-------------------------+ | Table has been created. | +-------------------------+ Fetched 1 row(s) in 4.10s - Check the table content.
[cdh-slave01:21000] default> show tables; Query: show tables +------------------------+ | name | +------------------------+ | call_center | | catalog_page | | catalog_returns | | catalog_sales | | customer | | customer_address | | customer_demographics | | date_dim | | household_demographics | | income_band | | inventory | | item | | promotion | | reason | | ship_mode | | store | | store_returns | | store_sales | | time_dim | | warehouse | | web_page | | web_returns | | web_sales | | web_site | +------------------------+ Fetched 24 row(s) in 0.03s - Run a TPC-DS query on Impala. You can query OSS data.
- Go to the sample-queries-tpcds directory that contains SQL files.
[root@cdh-master hive-testbench]# ls sample-queries-tpcds query12.sql query20.sql query27.sql query39.sql query46.sql query54.sql query64.sql query71.sql query7.sql query87.sql query93.sql README.md query13.sql query21.sql query28.sql query3.sql query48.sql query55.sql query65.sql query72.sql query80.sql query88.sql query94.sql testbench.settings query15.sql query22.sql query29.sql query40.sql query49.sql query56.sql query66.sql query73.sql query82.sql query89.sql query95.sql testbench-withATS.settings query17.sql query24.sql query31.sql query42.sql query50.sql query58.sql query67.sql query75.sql query83.sql query90.sql query96.sql query18.sql query25.sql query32.sql query43.sql query51.sql query60.sql query68.sql query76.sql query84.sql query91.sql query97.sql query19.sql query26.sql query34.sql query45.sql query52.sql query63.sql query70.sql query79.sql query85.sql query92.sql query98.sql - Run query13.sql.
[root@cdh-master hive-testbench]# impala-shell -i cdh-slave01 -d default -f sample-queries-tpcds/query13.sql Starting Impala Shell without Kerberos authentication Connected to cdh-slave01:21000 Server version: impalad version 3.0.0-cdh6.0.1 RELEASE(build9a74a5053de5f7b8dd983802e6d75e58d31472db) Query: use`default`Query: selectavg(ss_quantity) ,avg(ss_ext_sales_price) ,avg(ss_ext_wholesale_cost) ,sum(ss_ext_wholesale_cost) from store_sales ,store ,customer_demographics ,household_demographics ,customer_address ,date_dim where store.s_store_sk = store_sales.ss_store_sk and store_sales.ss_sold_date_sk = date_dim.d_date_sk and date_dim.d_year = 2001and((store_sales.ss_hdemo_sk=household_demographics.hd_demo_sk and customer_demographics.cd_demo_sk = store_sales.ss_cdemo_sk and customer_demographics.cd_marital_status = 'M'and customer_demographics.cd_education_status = '4 yr Degree'and store_sales.ss_sales_price between100.00and150.00and household_demographics.hd_dep_count = 3 )or (store_sales.ss_hdemo_sk=household_demographics.hd_demo_sk and customer_demographics.cd_demo_sk = store_sales.ss_cdemo_sk and customer_demographics.cd_marital_status = 'D'and customer_demographics.cd_education_status = 'Primary'and store_sales.ss_sales_price between50.00and100.00and household_demographics.hd_dep_count = 1 ) or (store_sales.ss_hdemo_sk=household_demographics.hd_demo_sk and customer_demographics.cd_demo_sk = ss_cdemo_sk and customer_demographics.cd_marital_status = 'U'and customer_demographics.cd_education_status = 'Advanced Degree'and store_sales.ss_sales_price between150.00and200.00and household_demographics.hd_dep_count = 1 )) and((store_sales.ss_addr_sk = customer_address.ca_address_sk and customer_address.ca_country = 'United States'and customer_address.ca_state in('KY', 'GA', 'NM') and store_sales.ss_net_profit between100and200 ) or (store_sales.ss_addr_sk = customer_address.ca_address_sk and customer_address.ca_country = 'United States'and customer_address.ca_state in('MT', 'OR', 'IN') and store_sales.ss_net_profit between150and300 ) or (store_sales.ss_addr_sk = customer_address.ca_address_sk and customer_address.ca_country = 'United States'and customer_address.ca_state in('WI', 'MO', 'WV') and store_sales.ss_net_profit between50and250 )) Query submitted at: 2018-10-3011:44:47(Coordinator: http://cdh-slave01:25000) Query progress can be monitored at: http://cdh-slave01:25000/query_plan?query_id=ff4b3157eddfc3c4:8a31c6500000000 +-------------------+-------------------------+----------------------------+----------------------------+ | avg(ss_quantity) | avg(ss_ext_sales_price) | avg(ss_ext_wholesale_cost) | sum(ss_ext_wholesale_cost) | +-------------------+-------------------------+----------------------------+----------------------------+ | 30.87106918238994 | 2352.642327044025 | 2162.600911949685 | 687707.09 | +-------------------+-------------------------+----------------------------+----------------------------+ Fetched 1 row(s) in 353.16s
The following tables are involved in this query: store, store_sales, customer_demographics, household_demographics, customer_address, and date_dim.[cdh-slave01:21000] default> show table STATS store; Query: show table STATS store +-------+--------+---------+--------------+-------------------+--------+-------------------+-------------------------------------------+ | #Rows | #Files | Size | Bytes Cached | CacheReplication | Format | Incremental stats | Location | +-------+--------+---------+--------------+-------------------+--------+-------------------+-------------------------------------------+ | -1 | 1 | 37.56KB | NOT CACHED | NOT CACHED | TEXT | false | oss://{your-bucket-name}/50/store | +-------+--------+---------+--------------+-------------------+--------+-------------------+-------------------------------------------+ Fetched 1 row(s) in 0.01s [cdh-slave01:21000] default> show table STATS store_sales; Query: show table STATS store_sales +-------+--------+---------+--------------+-------------------+--------+-------------------+-------------------------------------------------+ | #Rows | #Files | Size | Bytes Cached | CacheReplication | Format | Incremental stats | Location | +-------+--------+---------+--------------+-------------------+--------+-------------------+-------------------------------------------------+ | -1 | 50 | 18.75GB | NOT CACHED | NOT CACHED | TEXT | false | oss://{your-bucket-name}/50/store_sales | +-------+--------+---------+--------------+-------------------+--------+-------------------+-------------------------------------------------+ Fetched 1 row(s) in 0.01s [cdh-slave01:21000] default> show table STATS customer_demographics; Query: show table STATS customer_demographics +-------+--------+---------+--------------+-------------------+--------+-------------------+-----------------------------------------------------------+ | #Rows | #Files | Size | Bytes Cached | CacheReplication | Format | Incremental stats | Location | +-------+--------+---------+--------------+-------------------+--------+-------------------+-----------------------------------------------------------+ | -1 | 50 | 76.92MB | NOT CACHED | NOT CACHED | TEXT | false | oss://{your-bucket-name}/50/customer_demographics | +-------+--------+---------+--------------+-------------------+--------+-------------------+-----------------------------------------------------------+ Fetched 1 row(s) in 0.01s [cdh-slave01:21000] default> showtable STATS household_demographics; Query: show table STATS household_demographics +-------+--------+----------+--------------+-------------------+--------+-------------------+------------------------------------------------------------+ | #Rows | #Files | Size | Bytes Cached | CacheReplication | Format | Incremental stats | Location | +-------+--------+----------+--------------+-------------------+--------+-------------------+------------------------------------------------------------+ | -1 | 1 | 148.10KB | NOT CACHED | NOT CACHED | TEXT | false | oss://{your-bucket-name}/50/household_demographics | +-------+--------+----------+--------------+-------------------+--------+-------------------+------------------------------------------------------------+ Fetched 1 row(s) in 0.01s [cdh-slave01:21000] default> showtable STATS customer_address; Query: show table STATS customer_address +-------+--------+---------+--------------+-------------------+--------+-------------------+------------------------------------------------------+ | #Rows | #Files | Size | Bytes Cached | CacheReplication | Format | Incremental stats | Location | +-------+--------+---------+--------------+-------------------+--------+-------------------+------------------------------------------------------+ | -1 | 1 | 40.54MB | NOT CACHED | NOT CACHED | TEXT | false | oss://{your-bucket-name}/50/customer_address | +-------+--------+---------+--------------+-------------------+--------+-------------------+------------------------------------------------------+ Fetched 1 row(s) in 0.01s [cdh-slave01:21000] default> show table STATS date_dim; Query: show table STATS date_dim +-------+--------+--------+--------------+-------------------+--------+-------------------+----------------------------------------------+ | #Rows | #Files | Size | Bytes Cached | CacheReplication | Format | Incremental stats | Location | +-------+--------+--------+--------------+-------------------+--------+-------------------+----------------------------------------------+ | -1 | 1 | 9.84MB | NOT CACHED | NOT CACHED | TEXT | false | oss://{your-bucket-name}/50/date_dim | +-------+--------+--------+--------------+-------------------+--------+-------------------+----------------------------------------------+ Fetched 1 row(s) in 0.01s - Go to the sample-queries-tpcds directory that contains SQL files.
References
For more information, visit the following websites and see the following topics:
You can also access OSS through Alibaba Cloud E-MapReduce. EMR is an all-in-one enterprise-ready big data platform that provides cluster, job, and data management services based on the open source ecosystem. The ecosystem includes Hadoop, Spark, Kafka, Flink, and Storm. EMR provides seamless support for OSS. EMR is combined with OSS to provide access to OSS through the open source ecosystem and optimized technologies. For more information, see What is E-MapReduce?.