Data Lake - getting data into the zone

Data lakes exist to store and expose data in its native format without size or format constraints. Cloud data storage makes it possible to store large amounts of data without worrying about costs or data loss. Corporate lakes often store the same data multiple in transformed or enriched formats making them easier to use. My last two employers each had over 20 Petabytes of data in their lakes.

A well-managed lake organizes data based on usage, data quality, data trust levels, governance policies, data sensitivity and information lifecycles. Lake architects can spread their data across horizontal zones for purpose and/or vertical organization zones.  The actual zones for purpose vary by industry or company.

Zone Based Data Organization


This diagram demonstrates a zone structure that might be fit for a financial services company.  It assumes that company generates its' own data and receives data from external organizations.  Data exists in unstructured, semi-structured and structured format. 

Data validation is shown as an optional step. It is probably a requirement for certain zones.

A lake is only as useful as its' data catalog and associated metadata.  Data should be tracked and registered whenever it lands in one of the interior zones.
  • DMZ: This is the landing zone for externally sourced data.  Data is moved to the internal zones when it is considered safe for the internal network.
  • Quarantine: This is the zone for data that has problems. Data stops here if it fails data type, data format, data sensitivity or other checks.  
  • Vault: This zone exists for immutable or secure documents.  A company might put ID card images, contracts in this zone. Some companies provide vault storage to customers to securely hold their documents as a service.
  • Unstructured:  This zone exists to hold data that is not easily machine consumable.  Examples include call recordings, other audio and video files.
  • Structured Raw: This contains structured data in its original format irrespective of its utility or ease of use.  This is the home zone for any data that requires lineage tracking.
  • Structured Curated:  Data in this zone has been created for a specific set of consumers.  Machine Learning Features calculation results go into this zone. Copies of data in the Raw zone may be reformatted and transformed and stored in this zone.  Materialized views and denormalization go here.

Data Analytics

Business Analysts and Data Scientists need their own production like sandboxes where they can explore and transform production data.  Machine Learning training generates results data that must be stored somewhere for further analysis. 

Transient Data Analytics zones may be a good solution.  Data Analytic zones often automatically purge information after some period time on other conditions.

Other Zone Models

Sites have different views on the right zones based on their use cases and experience.

SourceSuggested Zones
SQL Chick Zones in a Data Lake 2017 Raw, Transient, Reference, Drop, Staged, Standardized Raw, Archive, Sandbox, Curated
Blue Granite Modern Data Architecture eBook
O'Reilly books: The Enterprise Data Lake Raw, Production, Dev, Sensitive
DZone Big Data Zone Transient, Raw, Trusted, Refined
NEOS Blog Raw, Structured, Curated, Customer, Analytics
Health Catalyst proposed healthcare zones Raw, Trusted, Refined, Sandbox
Zaloni blog Transient, Raw, Trusted, Refined
ScienceSoft blog Landing, Staging, Analytics, Curated

Access Controls

Zones may also be created or split to simplify coarse grain access controls.

History

Last modified 2019/11/25
Created 2019/11/11

Comments

Post a Comment

Popular posts from this blog

Understanding your WSL2 RAM and swap - Changing the default 50%-25%

Image
The Windows Subsystem for Linux operates as a virtual machine that can dynamically grow the amount of RAM to a maximum set at startup time.  Microsoft sets a default maximum RAM available to 50% of the physical memory and a swap-space that is 1/4 of the maximum WSL RAM.  You can scale those numbers up or down to allocate more or less RAM to the Linux instance. The first drawing shows the default WSL memory and swap space sizing. The images below show a developer machine that is running a dev environment in WSL2 and Docker Desktop.  Docker Desktop has two of its own WSL modules that need to be accounted for.  You can see that the memory would actually be oversubscribed, 3 x 50% if every VM used its maximum memory.  The actual amount of memory used is significantly smaller allowing every piece to fit. Click to Enlarge The second drawing shows the memory allocation on my 64GB laptop. WSL Linux defaults to a maximum RAM size of 5
Read more

Installing the RNDIS driver on Windows 11 to use USB Raspberry Pi as network attached

Image
I do a lot of my development and configuration via ssh into my Raspberry Pi Zero over the RNDIS connection. Some models of the Raspberry PIs can be configured with  gadget drivers  that let the Raspberry pi emulate different devices when plugged into computers via USB. My favorite gadget  is the network profile that makes a Raspberry Pi look like an RNDIS-attached network device.  All types of network services travel over an RNDIS device without knowing it is a USB hardware connection. A Raspberry Pi shows up as a Remote NDIS (RNDIS) device when you plug the Pi into a PC or Mac via a USB cable. The gadget  in the Windows Device Manager picture shows this RNDIS Gadget connectivity between a Windows machine and a Raspberry Pi. The Problem Windows 11 and Windows 10 no longer auto-installs the RNDIS driver that makes magic happen. Windows recognizes that the Raspberry Pi is some type of generic USB COM device. Manually running W indows Update  or  Update Driver  does  not  install the RNDI
Read more

DNS for Azure Point to Site (P2S) VPN - getting the internal IPs

Image
I wanted to access all my Azure resources without making any of them visible to the Internet.   The easiest give my local machine access to everything on my Azure Virtual Network (VNET) was to connect to it over VPN. It turns out creating Azure VPN gateways and connecting to Azure VPN endpoints is easy.  There are some subtleties in getting DNS name resolution to work that can confuse when first starting out. Setting the Stage There are a few ways to get to Azure endpoints and resources that are blocked from the internet.  We can  Create a Point-to-Site connection from our local machines to Azure Network Gateways Create a Site-to-Site network connection from our local networks to Azure Network Gateways. Use Bastion Hosts Use Cloud Shell Leave everything open to the internet. I chose a Point-to-Site (P2S) VPN connection that connects from my laptop to a VNet Gateway.  That joins my laptop
Read more