Feature request for supporting health and readiness checks in Dolt DB

[juhosyrjanen]

Hello,

Requesting support for defining health checks for metrics endpoint in Dolt to support better pod handling in Kubernetes.

We're currently investigating running Dolt in a statefulSet inside EKS and would appreciate if livenessProbe and readinessProbe objects could be supproted directly withing the Dolt container. eg. support defining the following blocks in Kubernetes manifests.

 livenessProbe:
   httpGet:
   path: /metrics/health
   port: 3308
   initialDelaySeconds: 20
   periodSeconds: 10
   failureThreshold: 5
   successThreshold: 1

Endpoint should return a OK 200 response when Dolt is healthy and ready to accept connections. readinessProbe could also be added to make sure that traffic is directed to the pod only when Dolt is ready to accept connections.

Could this be something to add to the roadmap?

(Sorry for the edit spam, accidentally published after writing the title :D )

[timsehn]

We're happy to investigate this request. @reltuk and @coffeegoddd will look today.

[coffeegoddd]

currently the dolthub/dolt-sql-server container supports these checks in a similar way to the mysql container, where you can do something like:

    livenessProbe:
      exec:
        command: ["dolt", "--host", "127.0.0.1", "--port", "3306", "--no-tls", "sql", "-q", "select current_timestamp();"]
      initialDelaySeconds: 60
      periodSeconds: 10
    readinessProbe:
      exec:
        command: ["dolt", "--host", "127.0.0.1", "--port", "3306", "--no-tls", "sql", "-q", "select current_timestamp();"]
      initialDelaySeconds: 40
      periodSeconds: 10

[timsehn]

Should we document this here: https://docs.dolthub.com/introduction/installation/docker

[coffeegoddd]

Updated docs here dolthub/docs#2001

[timsehn]

I'm going to resolve this assuming this solution works. Feel free to re-open if you want something different.

[bpf120]

@juhosyrjanen Thanks for considering Dolt. We'd love to learn more about your use case. Feel free to email me or swing by our Discord if you'd like to share.

[juhosyrjanen]

currently the dolthub/dolt-sql-server container supports these checks in a similar way to the mysql container, where you can do something like:

    livenessProbe:
      exec:
        command: ["dolt", "--host", "127.0.0.1", "--port", "3306", "--no-tls", "sql", "-q", "select current_timestamp();"]
      initialDelaySeconds: 60
      periodSeconds: 10
    readinessProbe:
      exec:
        command: ["dolt", "--host", "127.0.0.1", "--port", "3306", "--no-tls", "sql", "-q", "select current_timestamp();"]
      initialDelaySeconds: 40
      periodSeconds: 10

Thank you for pointing this out! This will do I believe for our use case.