HiveMall: Docker image setup

In a previous blog post I introduced HiveMall as a SQL based machine learning language available for Hadoop and integrated with Hive. If you have your own Hadoop/Big Data environment, I provided the installation instructions for Hivemall, in that blog post An alternative is to use Docker. There is a HiveMall Docker image available. A little warning before using this image. It isn't updated with the latest release but seems to get updated twice a year. Although you may not be running the latest version of HiveMall, you will have a working environment that will have almost all the functionality, bar a few minor new features and bug fixes. To get started, you need to make sure you have Docker running on your machine and you have logged into your account. The docker image is available from Docker Hub. Take note of the version number for the latest version of the docker image. In this example it is 20180924 

 

Open a terminal window and run the following command. This will download and extract all the image files.

docker pull hivemall/latest:20180924

Until everything is completed. This docker image has HDFS, Yarn and MapReduce installed and running. This will require the exposing of the ports for these services 8088, 50070 and 19888. To start the HiveMall docker image run

docker run -p 8088:8088 -p 50070:50070 -p 19888:19888 -it hivemall/latest:20180924

Consider creating a shell script for this, to make it easier each time you want to run the image.
Now seed Hive with some data. The typical example uses the IRIS data set. Run the following command to do this. This script downloads the IRIS data set, creates a number directories and then creates an external table, in Hive, to point to the IRIS data set.

cd $HOME && ./bin/prepare_iris.sh

Now open Hive and list the databases.

hive -S
hive> show databases;
OK
default
iris
Time taken: 0.131 seconds, Fetched: 2 row(s)

Connect to the IRIS database and list the tables within it.

hive> use iris;
hive> show tables;
iris_raw

Now query the data (150 records)

hive> select * from iris_raw;
1 Iris-setosa [5.1,3.5,1.4,0.2]
2 Iris-setosa [4.9,3.0,1.4,0.2]
3 Iris-setosa [4.7,3.2,1.3,0.2]
4 Iris-setosa [4.6,3.1,1.5,0.2]
5 Iris-setosa [5.0,3.6,1.4,0.2]
6 Iris-setosa [5.4,3.9,1.7,0.4]
7 Iris-setosa [4.6,3.4,1.4,0.3]
8 Iris-setosa [5.0,3.4,1.5,0.2]
9 Iris-setosa [4.4,2.9,1.4,0.2]
10 Iris-setosa [4.9,3.1,1.5,0.1]
11 Iris-setosa [5.4,3.7,1.5,0.2]
12 Iris-setosa [4.8,3.4,1.6,0.2]
13 Iris-setosa [4.8,3.0,1.4,0.1
...

Find the min and max values for each feature.

hive> select 
    > min(features[0]), max(features[0]),
    > min(features[1]), max(features[1]),
    > min(features[2]), max(features[2]),
    > min(features[3]), max(features[3])
    > from
    > iris_raw;

4.3  7.9  2.0  4.4  1.0  6.9  0.1  2.5

You are now up and running with HiveMall on Docker.

HiveML : Using SQL for ML on Big Data

It is widely recognised that SQL is one of the core languages that every data scientist needs to know. Not just know but know really well. If you are going to be working with data (big or small) you are going to use SQL to access the data. You may use some other tools and languages as part of your data science role, but for processing data SQL is king.

During the era of big data and hadoop it was all about moving the code to where the data was located. Over time we have seem a number of different languages and approaches being put forward to allow us to process the data in these big environments. One of the most common one is Spark. As with all languages there can be a large learning curve, and as newer languages become popular, the need to change and learn new languages is becoming a lot more frequent.

We have seen many of the main stream database vendors including machine learning in their databases, thereby allowing users to use machine learning using SQL. In the big data world there has been many attempts to do this, to building some SQL interfaces for machine learning in a big data environment.

One such (newer) SQL machine learning engine is called HiveMall. This will allow anyone with a basic level knowledge of SQL to quickly learn machine learning. Apache Hivemall is built to be a scalable machine learning library that runs on Apache Hive, Apache Spark, and Apache Pig.


Hivemall is currently at incubator stage under Apache and version 0.6 was released in December 2018.

I've a number of big data/hadoop environments in my home lab and build on a couple of cloud vendors (Oracle and AWS). I've completed the installation of Hivemall easily on my Oracle BigDataLite VM and my own custom build Hadoop environment on Oracle cloud. A few simple commands you will have Hivemall up and running. Initially installed for just Hive and then updated to use Spark.

Hivemall expands the analytical functions available in Hive, as well as providing data preparation and the typical range of machine learning functions that are necessary for 97+% of all machine learning use cases.

Download the hivemall-core-xxx-with-dependencies.jar file

# Setup Your Environment $HOME/.hiverc
add jar /home/myui/tmp/hivemall-core-xxx-with-dependencies.jar; 
source /home/myui/tmp/define-all.hive;

This automatically loads all Hivemall functions every time you start a Hive session

# Create a directory in HDFS for the JAR 
hadoop fs -mkdir -p /apps/hivemall 
hdfs dfs -chmod -R 777 /apps/hivemall 
cp hivemall-core-0.4.2-rc.2-with-dependencies.jar hivemall-with-dependencies.jar 
hdfs dfs -put hivemall-with-dependencies.jar /apps/hivemall/ 
hdfs dfs -put hivemall-with-dependencies.jar /apps/hive/warehouse

You might want to create a new DB in Hive for your Hivemall work.

CREATE DATABASE IF NOT EXISTS hivemall;
USE hivemall;

Then list all the Hivemall functions

show functions "hivemall.*";

+-----------------------------------------+--+
| tab_name                                |
+-----------------------------------------+--+
| hivemall.add_bias                       |
| hivemall.add_feature_index              |
| hivemall.amplify                        |
| hivemall.angular_distance               |
| hivemall.angular_similarity             |
...

Hivemall for ML using SQL is now up and running. Next step is to do try out the various analytical and ML functions.

Spark versus Flink

Spark is an open source Apache project that provides a framework for multi stage in-memory analytics. Spark is based on the Hadoop platform and can interface with Cassandra OpenStack Swift, Amazon S3, Kudu and HDFS. Spark comes with a suite of analytic and machine learning algorithm allowing you to perform a wide variety of analytics on you distribute Hadoop platform. This allows you to generate data insights, data enrichment and data aggregations for storage on Hadoop and to be used on other more main stream analytics as part of your traditional infrastructure. Spark is primarily aimed at batch type analytics but it does come with a capabilities for streaming data. When data needs to be analysed it is loaded into memory and the results are then written back to Hadoop.

Flink is another open source Apache project that provides a platform for analyzing and processing data that is in a distributed stream and/or batch data processing. Similarly to Spark, Flink comes with a set of APIs that allows for each integration in with Java, Scala and Python. The machine learning algorithms have been specifically tuned to work with streaming data specifically but can also work in batch oriented data. As Flink is focused on being able to process streaming data, it run on Yarn, works with HDFS, can be easily integrated with Kafka and can connect to various other data storage systems.

Although both Spark and Flink can process streaming data, when you examine the underlying architecture of these tools you will find that Flink is more specifically focused for streaming data and can process this data in a more efficient manner.

There has been some suggestions in recent weeks and months that Spark is now long the tool of choice for analytics on Hadoop. Instead everyone should be using Flink or something else. Perhaps it is too early to say this. You need to consider the number of companies that have invested significant amount of time and resources building and releasing products on top of Spark. These two products provide similar-ish functionality but each product are designed to process this data in a different manner. So it really depends on what kind of data you need to process, if it is bulk or streaming will determine which of these products you should use. In some environments it may be suitable to use both.

Will these tool replace the more traditional advanced analytics tools in organisations? the simple answer is No they won't replace them. Instead they will complement each other and if you have a Hadoop environment you will will probably end up using Spark to process the data on Hadoop. All other advanced analytics that are part of your more traditional environments you will use the traditional advanced analytics tools from the more main stream vendors.