Data In Motion: cloud

Using Cloudera Data Platform with Flow Management and Streams on Azure

Today I am going to be walking you through using Cloudera Data Platform (CDP) with Flow Management and Streams on Azure Cloud. To see a streaming demo video, please join my webinar (or see it on demand) at Streaming Data Pipelines with CDF in Azure. I'll share some additional how-to videos on using Apache NiFi and Apache Kafka in Azure very soon.

Apache NiFi on Azure CDP Data Hub

Sensors to ADLS/HDFS and Kafka

In the above process group we are using QueryRecord to segment JSON records and only pick ones where the Temperature in Fahrenheit is over 80 degrees then we pick out a few attributes to display from the record and send them to a slack channel.

To become a Kafka Producer you set a Record Reader for the type coming in, this is JSON in my case and then set a Record Writer for the type to send to the sensors topic. In this case we kept it as JSON, but we could convert to AVRO. I usually do that if I am going to be reading it with Cloudera Kafka Connect.

Our security is automagic and requires little for you to do in NiFi. I put in my username and password from CDP. The SSL context is setup for my when I create my datahub.

When I am writing to our Real-Time Data Mart (Apache Kudu), I enter my Kudu servers that I copied from the Kudu Data Mart Hardware page, put in my table name and your login info. I recommend UPSERT and use your Record Reader JSON.

For real use cases, you will need to spin up:

Public Cloud Data Hubs:

Streams Messaging Heavy Duty for AWS
Streams Messaging Heavy Duty for Azure
Flow Management Heavy Duty for AWS
Flow Management Heavy Duty for Azure

Software:

Apache Kafka 2.4.1
Cloudera Schema Registry 0.8.1
Cloudera Streams Messaging Manager 2.1.0

Apache NiFi 1.11.4

Apache NiFi Registry 0.5.0

Demo Source Code:

https://github.com/tspannhw/cdp-datahub-azure-nifikafka

Let's configure out Data Hubs in CDP in an Azure Environment. It is a few clicks and some naming and then it builds.

Under the Azure Portal

In Azure, we can examine the files we uploaded to the Azure object store.

Under the Data Lake SDX

NiFi and Kafka are autoconfigured to work with Apache Atlas under our environments Data Lake SDX. We can browse through the lineage for all the Kafka topics we use.

We can also see the flow for NiFi, HDFS and Kudu.

SMM

We can examine all of our Kafka infrastructure from Kafka Brokers, Topics, Consumers, Producers, Latency and Messages. We can also create and update topics.

Cloudera Manager

We still have access to all of our traditional items like Cloudera Manager to manage configuration of servers.

Under Real-Time Data Mart

We can view tables, create tables and query our table. Apache Hue is a great tool for accessing data in my Real-Time Data Mart in a datahub.

We can also look at table details in the Impala UI.

References

Use NiFi to call REST API, transform, route and store the data

Pick any REST API of your choice, but I have walked through this one to grab a number of weather stations reports. Weather or not we have good weather, we can query it anyway.

We are going to build a GenerateFlowFile to feed our REST calls.

[
{"url":"http://weather.gov/xml/current_obs/CWAV.xml"},
{"url":"http://weather.gov/xml/current_obs/KTTN.xml"},
{"url":"http://weather.gov/xml/current_obs/KEWR.xml"},
{"url":"http://weather.gov/xml/current_obs/KEWR.xml"},
{"url":"http://weather.gov/xml/current_obs/CWDK.xml"},
{"url":"http://weather.gov/xml/current_obs/CWDZ.xml"},
{"url":"http://weather.gov/xml/current_obs/CWFJ.xml"},
{"url":"http://weather.gov/xml/current_obs/PAEC.xml"},
{"url":"http://weather.gov/xml/current_obs/PAYA.xml"},
{"url":"http://weather.gov/xml/current_obs/PARY.xml"},
{"url":"http://weather.gov/xml/current_obs/K1R7.xml"},
{"url":"http://weather.gov/xml/current_obs/KFST.xml"},
{"url":"http://weather.gov/xml/current_obs/KSSF.xml"},
{"url":"http://weather.gov/xml/current_obs/KTFP.xml"},
{"url":"http://weather.gov/xml/current_obs/CYXY.xml"},
{"url":"http://weather.gov/xml/current_obs/KJFK.xml"},
{"url":"http://weather.gov/xml/current_obs/KISP.xml"},
{"url":"http://weather.gov/xml/current_obs/KLGA.xml"},
{"url":"http://weather.gov/xml/current_obs/KNYC.xml"},
{"url":"http://weather.gov/xml/current_obs/KJRB.xml"}
]

So we are using ${url} which will be one of these. Feel free to pick your favorite airports or locations near you. https://w1.weather.gov/xml/current_obs/index.xml

If you wish to choose your own data adventure, you can pick one of these others. You will have to build your own table if you wish to store it. They return CSV, JSON or XML, since we have record processors we don’t care. Just know which you pick.

Then we will use SplitJSON to split the JSON records into single rows.

Then use EvaluateJSONPath to extract the URL.

Now we are going to call those REST URLs with InvokeHTTP.

You will need to create a Standard SSL controller.

This is the default JDK JVM on Mac or some Centos 7. You may have a real password, if so you are awesome. If you don't know it, that's rough. You can build a new one with SSL.

For more cloud ingest fun, https://docs.cloudera.com/cdf-datahub/7.1.0/howto-data-ingest.html.

SSL Defaults (In CDP Datahub, one is built for you automagically, thanks Michael).

Truststore filename: /usr/lib/jvm/java-openjdk/jre/lib/security/cacerts

Truststore password: changeit

Truststore type: JKS

TLS Protocol: TLS

StandardSSLContextService for Your GET ${url}

We can tweak these defaults.

Then we are going to run a query to convert these and route based on our queries.

Example query on the current NOAA weather observations to look for temperature in fareneheit below 60 degrees. You can make a query with any of the fields in the where cause. Give it a try!

You will need to set the Record Writer and Record Reader:

Record Reader: XML

Record Writer: JSON

SELECT * FROM FLOWFILE
WHERE temp_f <= 60

SELECT * FROM FLOWFILE

Now we are splitting into three concurrent paths. This shows the power of Apache NiFi. We will write to Kudu, HDFS and Kafka.

For the results of our cold path (temp_f ⇐60), we will write to a Kudu table.

Kudu Masters: edge2ai-1.dim.local:7051 Table Name: impala::default.weatherkudu Record Reader: Infer Json Tree Reader Kudu Operation Type: UPSERT

Before you run this, go to Hue and build the table.

CREATE TABLE weatherkudu
(`location` STRING,`observation_time` STRING, `credit` STRING, `credit_url` STRING, `image` STRING, `suggested_pickup` STRING, `suggested_pickup_period` BIGINT,
`station_id` STRING, `latitude` DOUBLE, `longitude` DOUBLE,  `observation_time_rfc822` STRING, `weather` STRING, `temperature_string` STRING,
`temp_f` DOUBLE, `temp_c` DOUBLE, `relative_humidity` BIGINT, `wind_string` STRING, `wind_dir` STRING, `wind_degrees` BIGINT, `wind_mph` DOUBLE, `wind_gust_mph` DOUBLE, `wind_kt` BIGINT,
`wind_gust_kt` BIGINT, `pressure_string` STRING, `pressure_mb` DOUBLE, `pressure_in` DOUBLE, `dewpoint_string` STRING, `dewpoint_f` DOUBLE, `dewpoint_c` DOUBLE, `windchill_string` STRING,
`windchill_f` BIGINT, `windchill_c` BIGINT, `visibility_mi` DOUBLE, `icon_url_base` STRING, `two_day_history_url` STRING, `icon_url_name` STRING, `ob_url` STRING, `disclaimer_url` STRING,
`copyright_url` STRING, `privacy_policy_url` STRING,
PRIMARY KEY (`location`, `observation_time`)
)
PARTITION BY HASH PARTITIONS 4
STORED AS KUDU
TBLPROPERTIES ('kudu.num_tablet_replicas' = '1');

Let it run and query it. Kudu table queried via Impala, try it in Hue.

The Second fork is to Kafka, this will be for the 'all' path.

Kafka Brokers: edge2ai-1.dim.local:9092 Topic: weather Reader & Writer: reuse the JSON ones

The Third and final fork is to HDFS (could be ontop of S3 or Blob Storage) as Apache ORC files. This will also autogenerate the DDL for an external Hive table as an attribute, check your provenance after running.

JSON in and out for record readers/writers, you can adjust the time and size of your batch or use defaults.

Hadoop Config: /etc/hadoop/conf/hdfs-site.xml,/etc/hadoop/conf/core-site.xml Record Reader: Infer Json Directory: /tmp/weather Table Name: weather

Before we run, build the /tmp/weather directory in HDFS and give it 777 permissions. We can do this with Apache Hue.

Once we run we can get the table DDL and location:

Go to Hue to create your table.

CREATE EXTERNAL TABLE IF NOT EXISTS `weather`
(`credit` STRING, `credit_url` STRING, `image` STRUCT<`url`:STRING, `title`:STRING, `link`:STRING>, `suggested_pickup` STRING, `suggested_pickup_period` BIGINT,
`location` STRING, `station_id` STRING, `latitude` DOUBLE, `longitude` DOUBLE, `observation_time` STRING, `observation_time_rfc822` STRING, `weather` STRING, `temperature_string` STRING,
`temp_f` DOUBLE, `temp_c` DOUBLE, `relative_humidity` BIGINT, `wind_string` STRING, `wind_dir` STRING, `wind_degrees` BIGINT, `wind_mph` DOUBLE, `wind_gust_mph` DOUBLE, `wind_kt` BIGINT,
`wind_gust_kt` BIGINT, `pressure_string` STRING, `pressure_mb` DOUBLE, `pressure_in` DOUBLE, `dewpoint_string` STRING, `dewpoint_f` DOUBLE, `dewpoint_c` DOUBLE, `windchill_string` STRING,
`windchill_f` BIGINT, `windchill_c` BIGINT, `visibility_mi` DOUBLE, `icon_url_base` STRING, `two_day_history_url` STRING, `icon_url_name` STRING, `ob_url` STRING, `disclaimer_url` STRING,
`copyright_url` STRING, `privacy_policy_url` STRING)
STORED AS ORC
LOCATION '/tmp/weather'

You can now use Apache Hue to query your tables and do some weather analytics. When we are upserting into Kudu we are ensuring no duplicate reports for a weather station and observation time.

select `location`, weather, temp_f, wind_string, dewpoint_string, latitude, longitude, observation_time
from weatherkudu
order by observation_time desc, station_id asc

select *
from weather

In Atlas, we can see the flow.

Using Cloudera Data Platform with Flow Management and Streams on Azure

Cloudera Flow Management 101: Let's Build a Simple REST Ingest to Cloud Datawarehouse With LowCode. Powered by Apache NiFi

Use NiFi to call REST API, transform, route and store the data