KEDA | MongoDB

MongoDB ^Latest

Scale applications based on MongoDB queries.

Availability: v2.1+ Maintainer: Community

Trigger Specification

This specification describes the mongodb trigger that scales based on result of MongoDB query.

triggers:
  - type: mongodb
    metadata:
      # Required: database name
      dbName: "test"
      # Required: collection name
      collection: "test_collection"
      # Required: query expr, used by filter data
      query: '{"region":"eu-1","state":"running","plan":"planA"}'
      # Required: according to the number of query result, to scale job
      queryValue: "1"
      # Optional: This value will default to a masked version of the host and collection name if not set by the user (metrics name value would be then `mongodb-https---xxx-test_collection`)
      metricName: "global-metric"

Parameter list:

dbName - Name of the database
collection - Name of the collection
query - A MongoDB query that should return single numeric value
queryValue - A threshold that will define when scaling should occur
metricName - An optional name to assign to the metric. If not set KEDA will generate a name based on masked version of the server hostname and collection name. If using more than one trigger it is required that all metricName(s) be unique.

To provide information about how to connect to MongoDB you can provide

connectionStringFromEnv - A MongoDB connection string that should point to environment variable with valid value

Or provide more detailed information:

host - The host of the MongoDB server
port - The port of the MongoDB server
username - Username to authenticate with to MongoDB database
passwordFromEnv - Password for the given user

Authentication Parameters

You can authenticate by using connection string or password authentication.

Connection String Authentication:

connectionString - Connection string for MongoDB database

Password Authentication:

password - Password for the configured user to login to MongoDB database variables.

Example

Here is an example of how to deploy a scaled Job with the MongoDB scale trigger which uses TriggerAuthentication.

apiVersion: keda.sh/v1alpha1
kind: ScaledJob
metadata:
  name: mongodb-job
spec:
  jobTargetRef:
    template:
      spec:
        containers:
          - name: mongodb-update
            image: 1314520999/mongodb-update:latest
            args:
            - --connectStr=mongodb://test_user:test_password@mongoDB-svc.mongoDB.svc.cluster.local:27017/test
            - --dataBase=test
            - --collection=test_collection
            imagePullPolicy: IfNotPresent
        restartPolicy: Never
    backoffLimit: 1
  pollingInterval: 30             # Optional. Default: 30 seconds
  maxReplicaCount: 30             # Optional. Default: 100
  successfulJobsHistoryLimit: 0   # Optional. Default: 100. How many completed jobs should be kept.
  failedJobsHistoryLimit: 10      # Optional. Default: 100. How many failed jobs should be kept.
  triggers:
    - type: mongodb
      metadata:
        dbName: "test"
        collection: "test_collection"
        query: '{"region":"eu-1","state":"running","plan":"planA"}'
        queryValue: "1"
        metricName: "global-metric"
      authenticationRef:
        name: mongodb-trigger
---
apiVersion: keda.sh/v1alpha1
kind: TriggerAuthentication
metadata:
  name: mongodb-trigger
spec:
  secretTargetRef:
    - parameter: connectionString
      name: mongodb-secret
      key: connect
---
apiVersion: v1
kind: Secret
metadata:
  name: mongodb-secret
type: Opaque
data:
  connect: bW9uZ29kYjovL3Rlc3RfdXNlcjp0ZXN0X3Bhc3N3b3JkQG1vbmdvZGItc3ZjLm1vbmdvREIuc3ZjLmNsdXN0ZXIubG9jYWw6MjcwMTcvdGVzdA==

Trigger Specification

Authentication Parameters

Example

Currently available scalers for KEDA