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London PostgreSQL Meetup Group

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About us

Hey there! It’s great to have you on our page.

We’re a friendly group of PostgreSQL enthusiasts in and around London who meet every couple of months for a drink, a chat, and some good old Postgres talk.

Each meetup usually starts with a short talk to spark discussion, but anything in the PostgreSQL ecosystem is fair game — from performance tuning to migration stories (and everything in between).

Whether you’re a DBA, developer, or just curious about PostgreSQL — come join us! No fees, no formality, just great people and great conversations.

So if you’d like to see what the world’s most advanced open-source database holds for you, come along — and we’ll show you just how deep the rabbit hole goes. 🐘

Participation Policy
London PostgreSQL Meetup Group is dedicated to providing a safe, harassment-free and enjoyable meetup experience for everyone. Please be helpful, considerate, friendly, and respectful towards all other participants and venue staff.

We do not tolerate harassment of any members or organisers in any form. Imagery and language which promotes, supports, glorifies, or encourages acts of violence, harassment of any form, sexism or sexual misconduct, or hate speech, is not appropriate for any events including exhibition booths, talks and social events. Members violating these rules may be sanctioned or expelled from the meetup group and the events.

The meet-up abides by PostgreSQL Code of Conduct.

Trademark
Postgres, PostgreSQL and the Slonik Logo are trademarks or registered trademarks of the PostgreSQL Community Association of Canada, and used with their permission.

Upcoming events

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1 seat left
Zero-downtime major upgrades in practice
Tue, Apr 14 · 6:30 PM BST
Doggetts Coat and Badge, 1 Blackfriars Bridge SE1 9UD London, Central London, GB
We're excited to be back and pleased to say this event is being sponsored by pgMustard.

On the talks front, we have Anton Borisov and Vlad Bokov from Fresha who will take us through how they recently upgraded their fleet with zero-downtime.

We will then host our first ever debate, on a topic to be determined!

WHERE
Join us at Doggett's Coat and Badge on 14 April from 18:30.

PROGRAM
18:30 Welcome
19:00 Swapping the Elephant Without Breaking the Room: Zero-downtime Major PG upgrades in practice (Anton Borisov and Vlad Bokov, Fresha) - abstract below
19:45 Sandwiches and bar snacks (paid for by our sponsor)
20:00 Debate — topic TBD

ABSTRACT
Swapping the Elephant Without Breaking the Room: Zero-downtime Major PG upgrades in practice

Upgrading PostgreSQL across hundreds of production databases without downtime sounds impossible, especially when logical replication slots, Debezium CDC pipelines, and outbox event streams are in play.
At Fresha, we faced exactly that: mission-critical workloads still on PostgreSQL 12, and no safe way to reach 17 without freezing the business.

This talk walks through how we designed and automated a blue-green upgrade framework using logical decoding, controlled WAL overlap, and connector orchestration. We’ll dive into how Debezium connectors, replication origins, and PgBouncer pools were coordinated to guarantee continuity for both CDC and outbox topics, with rollback and dry-run modes built in.

Attendees will learn practical techniques for:
- Orchestrating zero-downtime Postgres major upgrades on RDS or self-managed clusters
- Managing replication slots and Debezium connectors safely across clusters
- Handling sequence alignment, WAL overlap, and connector state transitions
- Designing reversible, testable database cutovers
This is a practical session from real production experience: no magic tools, just PostgreSQL internals, Debezium, careful planning, and a few well-placed bash scripts.

SPEAKERS
Anton Borisov architects real-time data systems centered on PostgreSQL. At Fresha, he designs zero-downtime migrations, Debezium-based CDC pipelines, and overall data strategy integrating Postgres with Kafka and Flink.

His work spans query planning analysis, partitioning and indexing, autovacuum and bloat optimization, and performance tuning under high-concurrency workloads. He also builds downstream lakehouse integrations with Iceberg, Paimon, and StarRocks.

Anton publishes technical deep-dives on PostgreSQL internals, streaming infrastructure, and production reliability at medium.com/@borzoniusy

Vlad Bokov is a Staff Engineer at Fresha working on systems behind activity feeds and communication between partners and customers.

He deals with what breaks at scale: PostgreSQL under heavy write load, WAL bottlenecks, replication issues, Kafka pipelines, and zero-downtime migrations. Most of his work is about making production systems behave: fixing what is slow, unstable, or too expensive, and making trade-offs that hold up under pressure.

He works across Snowflake, StarRocks, PostgreSQL, Elasticsearch, and Redis, and is currently exploring newer streaming approaches, including Apache Fluss, for real-world workloads.

***

THE OFFICIAL BITS
The meet-up abides by PostgreSQL Code of Conduct.
Postgres, PostgreSQL and the Slonik Logo are trademarks or registered trademarks of the PostgreSQL Community Association of Canada, and used with their permission.
29 attendees