Apache Hive and Pig on Google Compute Engine

Copyright

Copyright 2013 Google Inc. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Disclaimer

This sample application is not an official Google product.

Summary

This sample application can be used to install Apache Hive and/or Pig onto a Hadoop master instance on Google Compute Engine.

Prerequisites

The sample application should be run from an Internet-connected machine such as a workstation/laptop.

The application assumes you have a Google Cloud Project created and that Google Cloud Storage and Google Compute Engine services are enabled on the project.

The application uses gsutil and gcutil, command line tools for Google Cloud Storage and Google Compute Engine respectively. Make sure to have the latest version of these Cloud SDK tools installed and added to your PATH environment variable.

Default project

The default project of the Cloud SDK tools must be set to the project of the Hadoop cluster.

Use the gcloud command to change the default project of the Cloud SDK:

gcloud config set project <project ID>

Hadoop cluster

You should already have a Hadoop cluster running on Google Compute Engine. This sample application has been tested with clusters created using both of the following:

• Solutions Cluster for Hadoop
• Bash Script Quickstart for Hadoop

In addition to a running Google Compute Engine cluster, the sample application requires the user running the installation scripts and the Google Compute Engine instances to have authorized access to a Google Cloud Storage bucket.

Cloud Storage bucket

Create a Google Cloud Storage bucket. This can be done by one of:

• Using an existing bucket. If you used either of the above Hadoop cluster bring-up packages, you may use the same bucket.

• Creating a new bucket from the "Cloud Storage" page on the project page of Developers Console

• Creating a new bucket with the gsutil command line tool:

    gsutil mb gs://<bucket name>
  

Make sure to create the bucket in the same Google Cloud project as that specified in the "Default project" section above.

Package Downloads

This sample application can be used to install just one or both of the packages discussed here. Which packages are installed will be driven by copying the respective tool's package archive into the "packages/toolname" subdirectory of the sample app prior to running the installation scripts.

Hive Package Setup

Create a directory for the Hive package as a subdirectory of the sample application:

mkdir -p packages/hive

Download Hive from hive.apache.org and copy the gzipped tar file into the packages/hive/ subdirectory. Testing of this sample application was performed with hive-0.11.0.tar.gz and hive-0.12.0.tar.gz.

Pig Package Setup

Create a directory for the Pig package as a subdirectory of the sample application::

mkdir -p packages/pig

Download Pig from pig.apache.org and copy the gzipped tar file into the packages/pig/ subdirectory. Testing of this sample application was performed with pig-0.11.1.tar.gz and pig-0.12.0.tar.gz.

If installing both tools, the packages subdirectory will now appear as:

packages/
  hive/
    hive-0.12.0.tar.gz
  pig/
    pig-0.12.0.tar.gz

Enter project details into properties file

Edit the file project_properties.sh found in the root directory of the sample application.

Update the GCS_PACKAGE_BUCKET value with the bucket name of the Google Cloud Storage associated with your Hadoop project, such as

readonly GCS_PACKAGE_BUCKET=myproject-bucket

Update the ZONE value with the Compute Engine zone associated with your Hadoop master instance, such as:

readonly ZONE=us-central1-a

Update the MASTER value with the name of the Compute Engine Hadoop master instance associated with your project, such as:

readonly MASTER=myproject-hm

Update the HADOOP_HOME value with the full directory path where hadoop is installed on the Hadoop master instance, such as:

readonly HADOOP_HOME=/home/hadoop/hadoop

or

readonly HADOOP_HOME=/home/hadoop/hadoop-install

The sample application will create a system userid named hdpuser on the Hadoop master instance. The software will be installed into the user's home directory /home/hdpuser.

If you would like to use a different username or install the software into a different directory, then update the HDP_USER, HDP_USER_HOME, and MASTER_INSTALL_DIR values in project_proerties.sh.

Push packages to cloud storage

From the root directory where this sample application has been installed, run:

$ ./scripts/packages-to-gcs__at__host.sh

This command will push the packages tree structure up to the GCS_PACKAGE_BUCKET configured above.

Run installation onto Hadoop master

From the root directory where this sample application has been installed, run:

$ ./scripts/install-packages-on-master__at__host.sh

This command will perform the installation onto the Hadoop master instance, including the following operations:

• Create the hdpuser
• Install software packages
• Set user privileges in the Google Compute Engine instance filesystem
• Set user privileges in the Hadoop File System (HDFS)
• Set up SSH keys for the hdpuser

Tests

On successful installation, the script will emit the appropriate command to connect to the hdpuser over SSH.

Once connected to the Hadoop master, the following steps will help verify a functioning installation.

The examples here use the /etc/passwd file, which contains no actual passwords and is publicly readable.

Hive Test

On the Hadoop master instance, under the hdpuser copy the /etc/passwd file from the file system into HDFS:

$ hadoop fs -put /etc/passwd /tmp

Start the Hive shell with the following command:

$ hive

At the Hive shell prompt enter:

CREATE TABLE passwd (
  user STRING,
  dummy STRING,
  uid INT,
  gid INT,
  name STRING,
  home STRING,
  shell STRING
)
ROW FORMAT DELIMITED
    FIELDS TERMINATED BY ':'
STORED AS TEXTFILE;

LOAD DATA INPATH '/tmp/passwd'
OVERWRITE INTO TABLE passwd;

SELECT shell, COUNT(*) shell_count
FROM passwd
GROUP BY shell
ORDER BY shell_count DESC;

This should start a MapReduce job sequence to first group and sum the shell types and secondly to sort the results.

The query results will be emitted to the console and should look something like:

/bin/bash 23
/usr/sbin/nologin 21
/bin/sync 1

To drop the table enter:

DROP TABLE passwd;

Note that you do NOT need to remove the passwd file from HDFS. The LOAD DATA command will have moved the file from /tmp/passwd to /user/hdpuser/warehouse. Dropping the passwd table will remove the file from /user/hdpuser/warehouse.

To exit the Hive shell enter:

exit;

Pig Test

On the Hadoop master instance, under the hdpuser copy the /etc/passwd file from the file system into HDFS:

$ hadoop fs -put /etc/passwd /tmp

Start the Pig shell with the following command:

$ pig

At the Pig shell prompt enter:

data = LOAD '/tmp/passwd'
       USING PigStorage(':')
       AS (user:CHARARRAY, dummy:CHARARRAY, uid:INT, gid:INT,
           name:CHARARRAY, home:CHARARRAY, shell:CHARARRAY);
grp = GROUP data BY (shell);
counts = FOREACH grp GENERATE
         FLATTEN(group), COUNT(data) AS shell_count:LONG;
res = ORDER counts BY shell_count DESC;
DUMP res;

This should start a MapReduce job sequence to first group and sum the shell types, secondly to sample the results for the subsequent sort job.

The query results will be emitted to the console and should look something like:

(/bin/bash,23)
(/usr/sbin/nologin,21)
(/bin/sync,1)

To exit the Pig shell enter:

quit;

When tests are completed, the passwd file can be removed with:

$ hadoop fs -rm /tmp/passwd

Post-installation cleanup

After installation, the software packages can be removed from Google Cloud Storage.

From the root directory where this sample application has been installed, run:

./scripts/packages-delete-from-gcs__at__host.sh

Appendix A

Using MySQL for the Hive Metastore

The default Hive installation uses a local Derby database to store Hive meta information (table and column names, column types, etc). This local database is fine for single-user/single-session usage, but a common setup is to configure Hive to use a MySQL database instance.

The following sections describe how to setup Hive to use a MySQL database either using Google Cloud SQL or a self-installed and managed MySQL database on the Google Compute Engine cluster master instance.

Google Cloud SQL

Google Cloud SQL is a MySQL database service on the Google Cloud Platform. Using Cloud SQL removes the need to install and maintain MySQL on Google Compute Engine.

The instructions here assume that you will use native MySQL JDBC driver and not the legacy Google JDBC driver.

Create and configure the Google Cloud SQL instance

In the Developers Console, create a Google Cloud SQL instance, as described at Getting Started. When creating the Cloud SQL instance, be sure to:

• Select Specify Compute Engine zone for the Preferred Location
• Select the GCE Zone of your Hadoop master instance
• Select Assign IP Address
• Add the external IP address of the Hadoop master instance to Authorized IP Addresses (you can also assign an IP address after creating the Cloud SQL instance).

After the Cloud SQL instance is created

• Select the instance link from the Cloud SQL instance list
• Go to the Access Control tab
  • Enter a root password in the appropriate field (make a note of it, you will need it for the steps below.)
  • Note the IP address assigned to the Cloud SQL instance; it will be used in the Hive configuration file as explained below.

Install the MySQL client

Connect to the Hadoop master instance:

gcutil ssh <hadoop-master>

Use the aptitude package manager to install the MySQL client:

sudo apt-get install --yes -f
sudo apt-get install --yes mysql-client

Create the Cloud SQL database

Launch the mysql client to connect to the Google Cloud SQL instance, replacing <cloud-sql-addr> with the assigned IP address of the Cloud SQL instance

mysql --host=<cloud-sql-addr> --user=root --password

The --password flag causes mysql to prompt for a password. Enter your root user password for the Cloud SQL instance.

Create the database hivemeta. Note that Hive requires the database to use latin1 character encoding.

CREATE DATABASE hivemeta CHARSET latin1;

Configure database user and grant privileges

Create the database user hdpuser:

CREATE USER hdpuser IDENTIFIED BY 'hdppassword';

[You should select your own password here in place of hdppassword.]

Issue grants on the hivemeta database to hdpuser:

GRANT ALL PRIVILEGES ON hivemeta.* TO hdpuser;

Install the MySQL native JDBC driver

Connect to the Hadoop master instance:

gcutil ssh <hadoop-master>

Use the aptitude package manager to install the MySQL JDBC driver:

sudo apt-get install --yes libmysql-java

Configure Hive to use Cloud SQL

Connect to the Hadoop master instance as the user hdpuser.

Add the JDBC driver JAR file to hive's CLASSPATH. The simplest method is to copy the file to the hive/lib/ directory:

cp /usr/share/java/mysql-connector-java.jar hive/lib/

Update the hive/conf/hive-site.xml file to connect to the Google Cloud SQL database. Add the following configuration, replacing <cloud-sql-addr> with the assigned IP address of the Cloud SQL instance, and replacing hdppassword with the database user password set earlier:

<property>
  <name>javax.jdo.option.ConnectionURL</name>
  <value>jdbc:mysql://<cloud-sql-addr>/hivemeta?createDatabaseIfNotExist=true</value>
</property>
<property>
  <name>javax.jdo.option.ConnectionDriverName</name>
  <value>com.mysql.jdbc.Driver</value>
</property>
<property>
  <name>javax.jdo.option.ConnectionUserName</name>
  <value>hdpuser</value>
</property>
<property>
  <name>javax.jdo.option.ConnectionPassword</name>
  <value>hdppassword</value>
</property>

As a password has been added to this configuration file, it is recommended that you make the file readable and writeable only by the hdpuser:

chmod 600 hive/conf/hive-site.xml

When run, Hive will now be able to use the Google Cloud SQL database as its metastore. The metastore database will be created with the first Hive DDL operation. For troubleshooting, check the Hive log at /tmp/hdpuser/hive.log.

MySQL on Google Compute Engine

MySQL can be installed and run on Google Compute Engine. The instructions here are for installing MySQL on the Hadoop master instance. MySQL could also be installed on a separate Google Compute Engine instance.

Install the MySQL server

Connect to the Hadoop master instance:

gcutil ssh <hadoop-master>

Use the aptitude package manager to install MySQL:

sudo apt-get install --yes -f
sudo apt-get install --yes mysql-server

Create MySQL database

Create a database for the Hive metastore with mysqladmin:

sudo mysqladmin create hivemeta

When completed, create a user for the Hive metastore.

Configure database user and grant privileges

Launch mysql:

sudo mysql

At the MySQL shell prompt, issue:

CREATE USER hdpuser@localhost IDENTIFIED BY 'hdppassword';
GRANT ALL PRIVILEGES ON hivemeta.* TO hdpuser@localhost;

[You should select your own password here in place of hdppassword.]

Install the MySQL native JDBC driver

Use the aptitude package manager to install the MySQL JDBC driver:

sudo apt-get install --yes libmysql-java

Configure Hive to use MySQL

Connect to the Hadoop master instance as the user hdpuser.

Add the JDBC driver JAR file to hive's CLASSPATH. The simplest method is to copy the file to the hive/lib/ directory:

cp /usr/share/java/mysql-connector-java.jar hive/lib/

Update the hive/conf/hive-site.xml file to connect to the Google Cloud SQL database. Add the following configuration, replacing hdppassword with the database user password set earlier:

<property>
  <name>javax.jdo.option.ConnectionURL</name>
  <value>jdbc:mysql://localhost/hivemeta?createDatabaseIfNotExist=true</value>
</property>
<property>
  <name>javax.jdo.option.ConnectionDriverName</name>
  <value>com.mysql.jdbc.Driver</value>
</property>
<property>
  <name>javax.jdo.option.ConnectionUserName</name>
  <value>hdpuser</value>
</property>
<property>
  <name>javax.jdo.option.ConnectionPassword</name>
  <value>hdppassword</value>
</property>

As a password has been added to this configuration file, it is recommended that you make the file readable and writeable only by the hdpuser:

chmod 600 ~hdpuser/hive/conf/hive-site.xml

When run, Hive will now be able to use the MySQL database as its metastore. The metastore database will be created with the first Hive DDL operation. For troubleshooting, check the Hive log at /tmp/hdpuser/hive.log.

Appendix B

This section lists some useful file locations on the Hadoop master instance:

 ---------------------|---------------------------------
| File Description    | Path                            |
|---------------------|---------------------------------|
| Hadoop binaries     | /home/[hadoop]/hadoop-<version> |
| Hive binaries       | /home/[hdpuser]/hive-<version>  |
| Pig binaries        | /home/[hdpuser]/pig-<version>   |
| HDFS NameNode Files | /hadoop/hdfs/name               |
| HDFS DataNode Files | /hadoop/hdfs/data               |
| Hadoop Logs         | /var/log/hadoop                 |
| MapReduce Logs      | /var/log/hadoop                 |
| Hive Logs           | /tmp/[hdpuser]                  |
| Pig Logs            | [Pig launch directory]          |
 ---------------------|---------------------------------