Category: Architecture

Vikas Hazrati takes us through the pros and cons of using event sourcing for a project:

You would always get a ton of literature on Event Sourcing and CQRS. The key question is WHEN do you use it? Under what circumstances? Is your problem really in need of ES?

I would not go into the details of what Event Sourcing and CQRS is. The industry stalwarts have covered that in adequate detail. This post delves into battle-tested scenarios on where we should have used and otherwise ignored ES.

Click through for an analysis of pros and cons, as well as some advice on what it all means.

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Hector Leano compares the delta and lambda architectures:

Generally, a simple data architecture is preferable to a complex one. Code complexity increases points of failure, requires more compute to run jobs, adds latency, and increases the need for support. As a result, data pipeline performance degrades over time, increasing costs while decreasing productivity as your data engineers spend more time troubleshooting and downstream users wait longer for data refreshes.

Complexity was perceived as a necessary evil for the automated data pipelines feeding business reporting, SQL analytics, and data science because the traditional approach for bringing together batch and streaming data required a lambda architecture. While a lambda architecture can handle large volumes of batch and streaming data, it increases complexity by requiring different code bases for batch and streaming, along with its tendency to cause data loss and corruption. In response to these data reliability issues, the traditional data pipeline architecture adds even more complexity by adding steps like validation, reprocessing for job failures, and manual update & merge.

On the one hand, lambda was always intended to be a compromise architecture based on the tools of the time. On the other hand, take this with as many grains of salt as you need given that the post comes from the primary company responsible for delta.

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I answer some questions:

On Thursday, I presented a session at PASS Summit entitled The Curated Data Platform. You can grab slides and links to additional information on my website. Thank you to everyone who attended the session.

During and after the session, I had a few questions come in from the audience, and I wanted to cover them here.

Most of the questions were around document databases, so check them out.

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Adrian Hills continues a series on multi-tenant SQL Server:

What you knew a few years ago might differ significantly from the reality today, whether you started off with a single tenant system that you pivoted quickly to support multiple tenants, or you envisioned 10s of tenants and ended up with 1000s. Whatever that reality is, when you experience pain points around the 3 considerations I covered in part 1 of this series (security, maintainability, and scalability), it can lead to a need to change the multi-tenancy approach you’re using. Often, the biggest driver for change is around performance and scalability and typically tends to be related to a need to move from a less-isolated multi-tenancy approach (single database) to a more-isolated approach that supports the scaling out of workloads (multiple databases).

In the steps below, I’ll cover the general path you can follow to successfully make an architectural change like this to the database layer. As a provider of database performance monitoring and DataOps tools, SentryOne offers some tools that can come in handy along the way, so I’ll call those out as we go.

Click through for guidance.

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Adrian Hills walks us through four database designs for multi-tenant data storage:

In my previous blog post, I talked about some of the key considerations around designing a multi-tenant system using SQL Server. There are several ways to implement multi-tenancy, and, as is often the case, there is no single “best” way but rather a range of options that each offer different trade-offs. The approach that is right for you depends on your objectives and needs for your specific environment. It’s important to consider which of these approaches best suit your requirements and goals based on the 3 core considerations from Multi-Tenancy with SQL Server, Part 1: security, maintainability (manageability), and scalability.

The following are the 4 approaches I will cover in this blog post:
1. Single database, shared schema
2. Single database, separate schema
3. Database per tenant
4. Multiple databases, multiple tenants per database, shared schema

I’ve worked with options 1, 3, and 4. Read on for Adrian’s thoughts. Ceteris paribus, my preference is 3. That said, I’ve worked in a situation where I migrated from 3 to 1 because there were thousands of customers, none of whom had more than hundreds of megabytes worth of data. 4 provides a good balance in that fashion, where you can bunch up smaller clients and give larger clients their own databases (and sometimes even servers). But if you’re going with options 2, 3, and 4, you probably want a central data warehouse which collects data across all four for internal use.

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