Configure Query Containers

Configuring Query Containers

When you create a continuous query, you can specify which query container should host that query. This enables you to isolate groups of queries to use a specific set of resources. A new installation of Drasi will include a default query container but you can also create your own.

Query Container Configuration

The Kubernetes resource definition for a Query Container has the following structure:

apiVersion: query.reactive-graph.io/v1
kind: QueryContainer
metadata:
  name: default
spec:
  queryHostCount: <query host count>
  defaultStore: <profile name>
  storage:
    <profile name>: 
      kind: <type>
      property1: <value1>
      property2: <value2>
    <profile name>: 
      kind: <type>
      property1: <value1>
      property2: <value2>
  results:
  - name: <property_1_name>
    value: <property_1_value>
  - name: <property_2_name>
    value: <property_2_value>

The following table provides a summary of these configuration settings:

Name	Description
apiVersion	Must have the value query.reactive-graph.io/v1
kind	Must have the value QueryContainer
metadata.name	The id of the Query Container. Must be unique. The id is used to manage the QueryContainer through Kubectl.
spec.queryHostCount	The number of query host instances to run for this query container. The queries within this container will be distributed across a number of query host instances. Scale this up to support a larger number of queries.
spec.defaultStore	The default storage profile for queries that do not request a specific one.
spec.storage	This section specifies the storage profiles that this container will support
spec.storage.(profile name)	The name of a storage profile identified by queries
spec.storage.(profile name).kind	The type of the storage profile. Valid values are `memory`, `redis` and `rocksDb`
spec.storage.(profile name).(property)	Specific config values for each storage type
spec.results	Name/value pairs used to configure the results store. These are documented below.

The following table provides a summary of the properties:

Name	Description
MONGO_URI	The MongoDB connection string to use, example: mongodb://rg-mongo:27017
MONGO_RESULT_STORE_DB_NAME	The DB name to use for the Mongo result store
MONGO_RESULT_STORE_COLL_NAME	The collection name to use for the Mongo result store

Example

apiVersion: query.reactive-graph.io/v1
kind: QueryContainer
metadata:
  name: default
spec:
  queryHostCount: 3
  defaultStore: rocks
  storage:
    memory:
      kind: memory
      enableArchive: false
    redis:
      kind: redis
      connectionString: redis://rg-redis:6379
    rocks:
      kind: rocksDb
      storageClass: azurefile-csi-premium
      enableArchive: false
      directIo: false
  results:
    MONGO_URI: mongodb://rg-mongo:27017
    MONGO_RESULT_STORE_DB_NAME: ReactiveGraph
    MONGO_RESULT_STORE_COLL_NAME: Results

In Memory storage options

Name	Description
enableArchive	Enable the archive feature that supports time travel functions

Redis storage options

Name	Description
connectionString	The Redis connection string, eg. redis://rg-redis:6379
cacheSize (optional)	Use an in-memory LRU cache

RocksDb storage options

Name	Description
storageClass (optional)	The storage class to provision the underlying volume. Must support `ReadWriteMany` access. (default :`azurefile-csi-premium`)
directIo (optional)	Enable direct IO for RocksDb (default: `false`)
enableArchive (optional)	Enable the archive feature that supports time travel functions (default: `false`)