Note: this blog has the same content as the series with the same name. With medium.com series being deprecated, I post the same content unchanged as regular blog here.

This series discusses various aspects of multi-cloud database management:

• What is multi-cloud database management?
• What are use cases for managing databases within and across different public and private clouds?
• What types of database management systems are available that satisfy multi-cloud use cases?
• Which deployment architectures support multi-cloud use cases?

… and many more.

☁️ If you are interested, please follow the series as it develops.

A small request …

This is the first time for…

Introduction

Multi-tenancy is a software architecture pattern in which a single or few instances of an application serve multiple tenants or customers, often hundreds or thousands. This approach is fundamental to cloud computing platforms where the underlying infrastructure is shared among multiple organizations. Basically, multi-tenancy can be thought of as a form of partitioning based on shared computing resources like databases. An analogy is tenants in an apartment building: shared infrastructure, but dedicated tenant space. Multi-tenancy is also the hallmark of most, if not all, software as a service (SaaS) applications.

An example could be an HR SaaS provider implementing its…

Introduction

This blog is a tutorial on how to set up a VPN between Google Cloud and AWS, create multi-zone subnetworks in each cloud and test any-to-any connectivity. For part of the setup this blog follows the community tutorial Google Cloud HA VPN interoperability guide for AWS and cites verbatim from it. This blog goes beyond the content of the community tutorial and includes setting up subnetworks as well as perform any-to-any testing of the network setup.

Please note upfront that this is a step-by-step manual setup all the way in case you want to understand and to execute all the…

What is zero downtime database migration and replication?

Zero downtime database migration and replication (Database Migration — Concepts and Principles (Part 1), Database Migration — Concepts and Principles (Part 2)) refers to migrating or replicating data from a source database to a target database without impacting the client’s access of the source database in terms of availability or scalability. A client can continue to operate on the source database while the database migration or replication progresses.

In the general case, database migration migrates all data from the source database to a target database with the goal to retire the source database and make the target database the primary…

tl;dr

Online database migration is an important — if not the most important — approach when migrating between schemas, between databases, or between data centers or clouds. There are many variations to online database migration (aka, zero downtime database migration): a popular one is dual-write and in my opinion a — if not the most — “dangerous” one when data consistency is paramount. …

As the COVID-19 outbreak continues (Visualizing the History of Pandemics) several application development projects and consortia are underway to develop an Immunity passport on mobile devices (“immunity apps”, “immunity certificates”) where the bearer can demonstrate having undergone a successful medical test for antibodies of a virus.

However, in context of COVID-19, there is a rub: having antibodies might not create immunity against COVID-19.

And, most important, there is a whole list of ethical issues that might arise that counter the benefit of an immunity app significantly.

The following resources provide you an overview of various aspects and might help you…