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oam/knowledge base/database lab.md
2024-11-06 21:18:41 +01:00

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# Database Lab
Database Lab Engine is an open-source platform developed by Postgres.ai to create instant, full-size clones of
production databases.<br/>
Use cases of the clones are to test database migrations, optimize SQL, or deploy full-size staging apps.
The website <https://Postgres.ai/> hosts the SaaS version of the Database Lab Engine.
Configuration file examples are available at <https://gitlab.com/postgres-ai/database-lab/-/tree/v3.0.0/configs>.
1. [Engine](#engine)
1. [Clones](#clones)
1. [Further readings](#further-readings)
1. [Sources](#sources)
## Engine
Config file in YAML format, at `~/.dblab/engine/configs/server.yml` by default.
Metadata files at `~/.dblab/engine/meta` by default. The metadata folder **must be writable**.
```sh
# Reload the configuration without downtime.
docker exec -it 'dblab_server' kill -SIGHUP 1
# Follow logs.
docker logs --since '1m' -f 'dblab_server'
docker logs --since '2024-05-01' -f 'dblab_server'
docker logs --since '2024-08-01T23:11:35' -f 'dblab_server'
```
Images for the _Standard_ and _Enterprise_ editions are available at
<https://gitlab.com/postgres-ai/se-images/container_registry/>.<br/>
Images for the _Community_ edition are available at <https://gitlab.com/postgres-ai/custom-images>.
## Clones
Database clones comes in two flavours:
- _Thick_ cloning: the regular way to copy data.<br/>
It is also how data is copied to Database Lab the first time a source is added.
Thick clones can be:
- _Logical_: do a regular dump and restore using `pg_dump` and `pg_restore`.
- _Physical_: done using `pg_basebackup` or restoring data from physical archives created by backup tools such as
WAL-E/WAL-G, Barman, pgBackRest, or pg_probackup.
> Managed PostgreSQL databases in cloud environments (e.g.: AWS RDS) support only the logical clone type.
The Engine supports continuous synchronization with the source databases.<br/>
Achieved by repeating the thick cloning method one initially used for the source.
- _Thin_ cloning: local containerized database clones based on CoW (Copy-on-Write) spin up in few seconds.<br/>
They share most of the data blocks, but logically they look fully independent.<br/>
The speed of thin cloning does **not** depend on the database size.
As of 2024-06, Database Lab Engine supports ZFS and LVM for thin cloning.<br/>
With ZFS, the Engine periodically creates a new snapshot of the data directory and maintains a set of snapshots. When
requesting a new clone, users choose which snapshot to use as base.
Clone DBs configuration starting point is at `~/.dblab/postgres_conf/postgresql.conf`.
## Further readings
- [Website]
- [Main repository]
- [Documentation]
- [`dblab`][dblab]
- [Installation guide for DBLab Community Edition][how to install dblab manually]
### Sources
- [Database Lab Engine configuration reference]
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[dblab]: dblab.md
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[database lab engine configuration reference]: https://postgres.ai/docs/reference-guides/database-lab-engine-configuration-reference
[documentation]: https://postgres.ai/docs/
[how to install dblab manually]: https://postgres.ai/docs/how-to-guides/administration/install-dle-manually
[main repository]: https://gitlab.com/postgres-ai/database-lab
[website]: https://postgres.ai/
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