Configure Database

Before creating a Stroom cluster, a database server must first be configured.

There are two options for deploying a MySQL database for Stroom:

Managed by Stroom K8s Operator

A Database server can be created and managed by the Operator. This is the recommended option, as the Operator will take care of the creation and storage of database credentials, which are shared securely with the Pod via the use of a Secret cluster resource.

Create a DatabaseServer resource manifest

Use the example at database-server.yaml .

See the DatabaseServer Custom Resource Definition (CRD) API documentation for an explanation of the various CRD fields.

By default, MySQL imposes a limit of 151 concurrent connections. If your Stroom cluster is larger than a few nodes, it is likely you will exceed this limit. Therefore, it is recommended to set the MySQL property max_connections to a suitable value.

Bear in mind the Operator generally consumes one connection per StroomCluster it manages, so be sure to include some headroom in your allocation.

You can specify this value via the spec.additionalConfig property as in the example below:

apiVersion: stroom.gchq.github.io/v1
kind: DatabaseServer
...
spec:
  additionalConfig:
    - max_connections=1000
...

Provision a PersistentVolume for the DatabaseServer

General instructions on creating a Kubernetes Persistent Volume (PV) are explained here .

The Operator will create StatefulSet when the DatabaseServer is deployed, which will attempt to claim a PersistentVolume matching the specification provided in DatabaseServer.spec.volumeClaim.

Fast, low-latency storage should be used for the Stroom database

Deploy the DatabaseServer to the cluster

kubectl apply -f database-server.yaml

Observe the Pod stroom-<database server name>-db start up. Once it’s reached Ready state, the server has started, and the databases you specified have been created.

Backup the created credentials

The Operator generates a Secret containing the passwords of the users root and stroomuser when it initially creates the DatabaseServer resource. These credentials should be backed up to a secure location, in the event the Secret is inadvertently deleted.

The Secret is named using the format: stroom-<db server name>-db (e.g. stroom-dev-db).

External

You may alternatively provide the connection details of an existing MySQL (or compatible) database server. This may be desirable if you have for instance, a replication-enabled MySQL InnoDB cluster.

Provision the server and Stroom databases

Store credentials in a Secret

Create a Secret in the same namespace as the StroomCluster, containing the key stroomuser, with the value set to the password of that user.

Upgrading or removing a DatabaseServer

A DatabaseServer cannot shut down while its dependent StroomCluster is running. This is a necessary safeguard to prevent database connectivity from being lost.

Upgrading or removing a DatabaseServer requires the StroomCluster be removed first.

Next steps

Configure a Stroom cluster