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CQL Configmaps

Description​

mr-cassop supports running CQL queries through Configmaps by setting the appropriate label.

The CQL Configmap can contain multiple entries with queries. In that case they will be executed in lexicographical order.

To prevent script execution multiple times, the operator sets an annotation with the hash of the data in the ConfgiMap. If any of the scripts are changed the operator will run the whole set again.

The CQL Configmaps are executed right after Reaper is up and running.

You can also run repairs on a specific keyspace by setting the cql-repairKeyspace annotation.

Examples​

How to create a query in CQL Configmap​

Create CQL Configmap:

kubectl create configmap my-cql-queries --from-literal=test-query="CREATE KEYSPACE IF NOT EXISTS test_keyspace WITH REPLICATION = { 'class' : 'NetworkTopologyStrategy', 'dc1' : 3 };"

By default, the mr-cassop is looking for CQL Configmaps with the label cql-scripts, but you can override this value in the CassandraCluster resource:

spec:
  cqlConfigMapLabelKey: cql-scripts

Update the CQL Configmap label. Only the label key is required, the value is not important.

kubectl label configmap/my-cql-queries cql-scripts=query

Update CQL Configmap label with cluster name value:

kubectl get cassandracluster
NAME           AGE
test-cluster   60s
kubectl annotate configmap/my-cql-queries cassandra-cluster-instance=test-cluster

How to create CQL query and repair for keyspace in CQL Configmap​

Create CQL Configmap:

kubectl create configmap my-cql-queries --from-literal=test-query="CREATE KEYSPACE IF NOT EXISTS test_keyspace2 WITH REPLICATION = { 'class' : 'NetworkTopologyStrategy', 'dc1' : 3 };"

Update CQL Configmap label and annotations:

kubectl label configmap/my-cql-queries cql-scripts=query
kubectl annotate configmap/my-cql-queries cql-repairKeyspace=test_keyspace2

Update CQL Configmap label with cluster name value:

kubectl get cassandracluster
NAME           AGE
test-cluster   60s
kubectl annotate configmap/my-cql-queries cassandra-cluster-instance=test-cluster
caution

Under the hood, the operator uses the Apache Cassandra Go driver to execute CQL queries. That imposes restrictions on the kind of CQL queries you can run. For example, USE queries are not allowed, INSERT queries can't be executed (since the Query function requires the values to be passed to the function), etc.

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