A Monolith on the Dissecting Table: The Strangler Fig Pattern in Action @ Devoxx Poland 2023

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A Monolith on the Dissecting Table: The Strangler Fig Pattern in Action @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 2

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! It's me ... Hans-Peter • Developer ! Advocate @ Red Hat • Open-Source Enthusiast • 4x Confluent Community Catalyst • MongoDB Champion since 2020 • based in Graz, Austria " @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 3

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system migrations are challenging @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 4

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! What about the big rewrite and a hard cut-over? ! @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 5

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BIG BANG migrations often doomed to failure @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 6

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"If you do a big bang rewrite, the only thing you're certain of is a big bang." — Martin Fowler @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 7

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 8

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Migration Goal • gradually evolve from old into new • support (temporary) coexistence • avoid risky big bang rewrite @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 9

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strangler fig pattern to the rescue @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 10

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 11

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 12

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 13

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strangler fig pattern by example @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 14

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 15

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 16

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Change-Data-Capture @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 17

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 18

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Debezium's supported Databases @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 19

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Open-Source Change-Data-Capture • captures data changes by tapping into DB's TX log • change events propagated via Apache Kafka / Connect @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 20

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Open-Source Change-Data-Capture • captures data changes by tapping into DB's TX log • change events propagated via other messaging systems @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 21

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 22

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 23

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 24

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 25

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 26

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 27

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 28

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 29

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CDC Pipeline Concern #1 We're leaking our data / domain model. I want an anti-corruption layer. @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 30

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Single Message Transforms @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 31

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Single Message Transforms @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 32

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CDC Pipeline Concern #2 But this only replicates data "row by row". I might need aggregate structures. @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 33

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Stream Processor for Joining @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 34

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 35

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 36

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Wrapping Up • incremental migration → baby steps • pause / stop without losing spent $$$ • extraction steps ideally reversible @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 37

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⚠ minimize migration risk @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 38

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Let's stay in touch! ! @hpgrahsl @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 39

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! Give it a try! " • Strangler Fig Pattern Demo https://bit.ly/sfp-devoxxpl23 @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 40

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 41

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Links & Resources • Demo Repository https://github.com/hpgrahsl/sfp-devoxxpl23 • Developer Sandbox for Openshift https://developers.redhat.com/developer-sandbox • Debezium Website https://debezium.io • Quarkus https://quarkus.io @hpgrahsl | #DevoxxPL - Kraków, Poland | 2023 42

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@hpgrahsl | #DevoxxPL - Kraków, Poland | 2023