Is it possible to implement ArangoDB sharding by database (rather than collection or shardKey)?

one of options to run multiple instances is to use Docker Swarm.with example below you can run multiple instances of ArangoDB

you'll need

• Docker
• with initialized Swarm docker swarm init [OPTIONS]
• optionaly with more nodes added via docker swarm join [OPTIONS] HOST:PORT
• and set group labels on nodes via docker node update --label-add group=group1 [node-name], group1 on first node, group2 on second node and so on

then save code below as docker-stack-arango.yml

version: '3.3'services:  arangodb:    image: "${ARANGO_IMAGE}"    environment:      ARANGO_ROOT_PASSWORD: "${ARANGO_ROOT_PASSWORD}"      ARANGO_STORAGE_ENGINE: "${ARANGO_STORAGE_ENGINE}"    volumes:      - arangodb:/var/lib/arangodb3      - arangodb_apps:/var/lib/arangodb3-apps    ports:      - target: 8529        published: $ARANGO_PUBLISHED_PORT        protocol: tcp        mode: ingress    deploy:      mode: replicated      replicas: 1      endpoint_mode: vip      placement:        constraints:          - node.labels.group==$INSTANCE_GROUP      resources:        limits:          cpus: $LIMITS_CPU          memory: $LIMITS_MEMORY      restart_policy:        condition: any        delay: 5s        max_attempts: 3        window: 60s      update_config:        parallelism: 1        delay: 30s    stop_grace_period: 60svolumes:  arangodb:    external:      name: ${ARANGO_VOLUME}  arangodb_apps:    external:      name: ${ARANGO_APPS_VOLUME}

update and run config in shell/bash

export INSTANCE_GROUP="group1"export INSTANCE_NAME="arango1"export INSTANCE_PORT=8529export INSTANCE_PASSWORD="do-not-use-this-password-in-production"export ARANGO_IMAGE_TAG="3.4.0"export ARANGO_IMAGE_REPO="arangodb/arangodb"export ARANGO_IMAGE="${ARANGO_IMAGE_REPO}:${ARANGO_IMAGE_TAG}"export ARANGO_VOLUME="arangodb-${INSTANCE_NAME}--3.4.0"export ARANGO_APPS_VOLUME="arangodb-apps-${INSTANCE_NAME}--3.4.0"export ARANGO_PUBLISHED_PORT=$INSTANCE_PORTexport ARANGO_STORAGE_ENGINE="rocksdb"export ARANGO_ROOT_PASSWORD=$INSTANCE_PASSWORDexport LIMITS_CPU=1export LIMITS_MEMORY=1024M

and then run deploy

docker stack deploy -c ./docker-stack-arango.yml $INSTANCE_NAME

to deploy second instance change INSTANCE_NAME, INSTANCE_PORT and INSTANCE_GROUP and run deploy again

then you can access instances via ip of any node with configured port

No. Sharding is implemented solely for the purpose of distributing documents of any collection over multiple database servers. This is a means, to implement memory as well as load balancing on ArangoDB clusters.

Arango can also be implemented using Kubernetes instead of Docker swarm (probably better).You could even create multiple server standalone instances if you really wanted to. Whichever the implementation technology though, I guess what the other answers are trying to indicate is that if you have multiple independent databases, you could, have multiple instances of ArangoDB (or any other DB for that matter). The only time you would want keep multiple DBs in one instance is if the DBs are small enough that they will not compete for the server's resources.

Dividing you current instance should be fairly straight forward as you can backup, restore and manipulate the different DBs independently. Sharding and other associated concepts like partitioning are meant for times where you have to keep all the data within a single database. In that case, one needs to find a way to divide the data in multiple servers while keeping it as a single unit. That does not appear to be the case for here.

If you want to find out more on how to use ArangoDb with Kubernetes, you can find the documentation here