Manage a workerpool

A workerpool manager is an essential actor in the iExec network. It will be in charge of proposing available computing resources (workers) to task requesters.

The iexec-core software will take care of handling tasks comming from blockchain events and will distribute it to alive workers.

Prerequisites

Workers are deployed with docker containers. Follow instructions on the docker website for installation.

Docker compose file

Since all the services used by iExec run in docker, we will use docker-compose to start the scheduler and its related service. You can follow the instructions on the the docker compose website to install it.

In the docker compose file, you will find the following components:

Database service

A database is required for running the scheduler.

  image: mongo:4-xenial
  container_name: mongo
  networks:
    - iexec-net
  restart: unless-stopped

mongo_ui:
  image: mongo-express:0.49
  container_name: mongo_ui
  environment:
    - ME_CONFIG_BASICAUTH_USERNAME=mongoUiAdmin
    - ME_CONFIG_BASICAUTH_PASSWORD=mongoUiPassw0rd
  ports:
    - 8081:8081
  networks:
    - iexec-net
  depends_on:
    - mongo
  restart: unless-stopped

IPFS service

An IPFS node is required for running the scheduler.

ipfs:
  image: jbenet/go-ipfs:latest
  container_name: ipfs-node
  ports:
    - 4001:4001
  volumes:
    - ipfs-docker-staging:/export
    - ipfs-docker-data:/data/ipfs
  networks:
    - iexec-net
  restart: unless-stopped

Scheduler service

The main component is the scheduler service. In the docker compose file, it is defined as follow:

core:
  image: iexechub/iexec-core:3.0.0
  container_name: core
  environment:
    - IEXEC_CORE_WALLET_PATH=/iexec-wallet/wallet.json
    - IEXEC_CORE_WALLET_PASSWORD=myWalletPassw0rd
    - IEXEC_PRIVATE_CHAIN_ADDRESS=https://my-jsonrpc-enabled-ethereum-node.com
    - IEXEC_PUBLIC_CHAIN_ADDRESS=https://my-default-public-ethereum-node-for-workers.com
    - IEXEC_HUB_ADDRESS=0xiexechubaddress
    - POOL_ADDRESS=0xmyworkerpool
    - IEXEC_START_BLOCK_NUMBER=0
    - REVEAL_TIMEOUT_PERIOD=120000
    - IEXEC_ASK_REPLICATE_PERIOD=30000
    - IEXEC_RESULT_REPOSITORY_HOST=my-workerpool.com
    - IEXEC_RESULT_REPOSITORY_PORT=18090
    - IEXEC_CHAIN_ID=42
    - MONGO_HOST=mongo
    - IEXEC_IPFS_HOST=ipfs
    - IEXEC_IPFS_PORT=5001
    - IEXEC_CORE_PORT=18090
    - IEXEC_SMS_HOST=http://my-sms.com
  volumes:
    - ./wallet.json:/iexec-wallet/wallet.json
  ports:
    - 18090:18090
  networks:
    - iexec-net
  depends_on:
    - mongo
    - ipfs
  restart: unless-stopped

Like the database, the different variables used here are defined in the file .env and should be modified.

Start a scheduler

To start a scheduler, it is pretty straightforward since the scheduler can be started like any docker compose service, so it can be started using:

docker-compose up -d

Please note that you need to make sure the scheduler has finished its start before starting any worker that will connect to the pool.

Stop a scheduler

In a similar fashion, the scheduler can be stopped with the following command:

docker-compose down

Please note that once the scheduler is turned off, the workers will not work anymore.