`grafana-cratedb-source`

[amotl]

Introduction

Years ago, there have been dedicated CrateDB data source adapters for Grafana, talking HTTP to CrateDB.

• https://github.com/crate/grafana-datasource-plugin-crate
• https://github.com/raintank/crate-datasource

Because CrateDB talks PostgreSQL today, the built-in PostgreSQL data source adapter for Grafana can easily be used with CrateDB now, so we have been able to cease maintenance on the HTTP-based data source adapters.

Problem I

However, this has the significant drawback that CrateDB has no dedicated representation on Grafana's realms today, while all other vendors have. Relevant network effects have been underestimated far too long.

-- https://grafana.com/grafana/plugins/data-source-plugins/

Problem II

Currently, the query builder can't be used to emit an SQL query based on the template shown at crate/cratedb-examples#1442 (review). However, this is crucial for processing big data.

Solution

Provide a data source for CrateDB which technically wraps around the built-in PostgreSQL data source without much ado, to get the CrateDB logo into Grafana's marketplace again.

/cc @seut, @joerg84

[amotl]

Good morning. Until we can conceive and maintain a dedicated adapter, please treat corresponding issues that harm Grafana interoperability as bugs, when possible. Thank you! 🙏

• Support parse_ident function crate#18660

^^ It's not just like parse_ident() is unsupported, but the consequence is that apparently, the main killer feature of the query builder component of the most popular dashboarding application on earth, that allows interactive exploration of database table columns, is broken with CrateDB, when pretending to be PostgreSQL?

/cc @hammerhead

Update: CrateDB 6.3.0 will resolve this.

[seut]

Until we can conceive and maintain a dedicated adapter, please treat corresponding issues that harm Grafana interoperability as bugs, when possible. Thank you!

Afaik a dedicated CrateDB adapter should be a pure wrapper around the original postgresql code, at best not even using any forked code. Such any issues with the postgresql adaper will ever be bugs/issues.

[amotl]

Yes, that would be the optimal way to go. Let's evaluate if this is possible.

[amotl]

Those files in the Grafana source tree for PostgreSQL would be relevant to be adjusted for CrateDB. Unless we can bring CrateDB support into Grafana mainline, we will probably need to copy corresponding code, or at least fragments thereof, into a dedicated plugin.

• https://github.com/grafana/grafana/blob/main/pkg/tsdb/grafana-postgresql-datasource/postgres.go
• https://github.com/grafana/grafana/tree/main/public/app/plugins/datasource/grafana-postgresql-datasource

As we can see support for other PostgreSQL-compatible databases like Amazon Redshift is also maintained by the Grafana Labs data source team, I think it is probably a good idea to ask them for guidance.

@simonprickett helped us to figure out why Grafana 12.4 failed to connect to CrateDB by getting in touch with them, promptly coming back with the news Grafana 12.4 switched the PostgreSQL driver to pgx, so our core team was able to fix relevant discrepancies quickly (GH-297); thank you again! Maybe he is able to connect us with @zoltanbedi, @kevinwcyu, @iwysiu, or other members of Grafana Labs who could support us here? 🙏