Compact cluster

Cloudify Compact Cluster

compact_Cluster

Cloudify clustering architecture is based on an active-active model, and on service separation, allowing Cloudify to offer a high availability architecture while keeping the flexibility to leverage a managed external PostgreSQL database service or RabbitMQ messaging queue. The separation of services approach was introduced in v5.0.5 and improved the scaling ability and the robustness of the failover mechanism thanks to the active-active approach and to the usage of industry-standard replication and synchronization concepts.

With that, when using the complete high availability cluster a minimal number of 9 VMs is required. Some organizations are seeking a more compact model leveraging just 3 VMs for ease of maintenance and control. The 3 nodes cluster topology was designed to answer this. A 3 VM compact model still offering an active-active approach and complete high availability, yet leveraging just 3 VMs for simplified management and operational flows. In this model, each of the VMs is running all of the Cloudify services, namely the Cloudify Manager, the PostgrSQL database and the Rabbit messaging queue.

Note that while all services are running on each of the VMs, it does not necessarily mean that communication is always internal in the VM. For example, the database high availability setup is such that at any given time one node is active while the other nodes are in synchronous replica and async replica. That means that all the managers will be communicating with the active database node regardless if it is a local or a remote one.

Before you start the manual process of installing a Cloudify cluster, you might want to consider using the Cluster Manager package that automates it.

This guide describes the process of configuring and installing such a cluster:

Preparation and Certificates Setup
Installing Services
Day 2 Commands

Preparation and Certificates Setup

Preparing the Environment

Ensure you have three VMs with cfy_manager available on each:
- Please follow the prerequisites and sizing guidelines to configure each VM.
- In order to install the cfy_manager CLI:
  1. Download the Cloudify Manager Install RPM.
  2. Run sudo yum install -y <RPM file path>.
All VMs should be on the same network and if there is firewall/security group, make sure used ports are open and not blocking any of our services.
Each VM must have a license file on it.
You should also prepare a load balancer to distribute the load over the managers.

Certificates Setup

Please refer to the Cluster certificates setup guide. Each VM should have its own certificates and CA certificate on it.

Installing Services

Important Notes:

All passwords given are for example purposes only and shouldn’t be used in production.
All placeholders that should be filled-in are indicated by angle brackets, e.g. <fill this in>. Before you run any install commands make sure you haven’t got any angle brackets left in the files.
All hostnames used should be just the hostname, not including the domain.
NOTE: If you wish to use FQDNs instead, then you will need to alter the RabbitMQ config and add use_long_name: true in the rabbitmq section. Caution: Setting this, will require manually specifying the target node and using the --longnames argument for any rabbitmqctl operations.

Installing PostgreSQL DB Services

On each node, create the file /etc/cloudify/db_config.yaml, containing:

manager:
  private_ip: <this node IP address>
  public_ip: <this node IP address>

postgresql_server:
  postgres_password: 'areallystrongandsecretpasswordforpostgres'

  cert_path: '<this node local certificate path>'
  key_path: '<this node local private key path>'
  ca_path: '<local CA certificate path>'

  cluster:
    nodes:
      <node-1 hostname>:
        ip: <node-1 IP address>
      <node-2 hostname>:
        ip: <node-2 IP address>
      <node-3 hostname>:
        ip: <node-3 IP address>

    etcd:
      cluster_token: 'astrongandsecretpasswordlikestring'
      root_password: 'anotherstrongandsecretbutdifferentpassword'
      patroni_password: 'yetanotherstrongandsecretpassword'

    patroni:
      rest_user: patroni
      rest_password: 'strongandsecretpatronirestpassword'

    postgres:
      replicator_password: 'stillanotherstrongandsecretpassword'

prometheus:
  credentials:
    username: 'monitoringusername'
    password: 'longyeteasytorememberstringasapassword'

  cert_path: '<this node local certificate path>'
  key_path: '<this node local private key path>'
  ca_path: '<local CA certificate path>'

services_to_install:
  - database_service
  - monitoring_service

Then, run cfy_manager install -c /etc/cloudify/db_config.yaml --verbose.

After PostgreSQL service is installed on all three nodes, verify that everything looks healthy with running on one of them: cfy_manager dbs list -c /etc/cloudify/db_config.yaml.

Installing RabbitMQ Services

On each node, create the file /etc/cloudify/rabbitmq_config.yaml, containing:

manager:
  private_ip: <this node IP address>
  public_ip: <this node IP address>

rabbitmq:
  username: cloudify
  password: areallystrongandsecretpasswordforrabbit

  cert_path: '<this node local certificate path>'
  key_path: '<this node local private key path>'
  ca_path: '<local CA certificate path>'

  cluster_members:
    <node-1 hostname>:
      networks:
        default: <node-1 IP address>
        load_balancer: <the load-balancer IP address>
    <node-2 hostname>:
      networks:
        default: <node-2 IP address>
        load_balancer: <the load-balancer IP address>
    <node-3 hostname>:
      networks:
        default: <node-3 IP address>
        load_balancer: <the load-balancer IP address>

  nodename: <this node hostname>

  join_cluster: <node-1 hostname; **should be left blank on node-1**>

  erlang_cookie: anothersecurepasswordlikestring

prometheus:
  credentials:
    username: 'monitoringusername'
    password: 'longyeteasytorememberstringasapassword'

  cert_path: '<this node local certificate path>'
  key_path: '<this node local private key path>'
  ca_path: '<local CA certificate path>'

services_to_install:
  - queue_service
  - monitoring_service

Then, run cfy_manager install -c /etc/cloudify/rabbitmq_config.yaml --verbose.

After RabbitMQ service is installed on all three nodes, verify that everything looks healthy with running on one of them: cfy_manager brokers list -c /etc/cloudify/rabbitmq_config.yaml.

Installing Cloudify Management Services

On each node, create the file /etc/cloudify/manager_config.yaml, containing:

manager:
  private_ip: <this node IP address>
  public_ip: <this node IP address>
  security:
    ssl_enabled: true
    admin_password: strongsecretadminpassword
  cloudify_license_path: <local license path>

postgresql_server:
  ca_path: '<local CA certificate path>'

  cluster:
    nodes:
      <node-1 hostname>:
        ip: <node-1 IP address>
      <node-2 hostname>:
        ip: <node-2 IP address>
      <node-3 hostname>:
        ip: <node-3 IP address>

postgresql_client:
  server_password: 'areallystrongandsecretpasswordforpostgres'
  ssl_enabled: true

networks:
  default: <this node IP address>
  load_balancer: <the load-balancer IP address>

rabbitmq:
  username: cloudify
  password: areallystrongandsecretpasswordforrabbit

  ca_path: '<local CA certificate path>'

  cluster_members:
    <node-1 hostname>:
      networks:
        default: <node-1 IP address>
        load_balancer: <the load-balancer IP address>
    <node-2 hostname>:
      networks:
        default: <node-2 IP address>
        load_balancer: <the load-balancer IP address>
    <node-3 hostname>:
      networks:
        default: <node-3 IP address>
        load_balancer: <the load-balancer IP address>

ssl_inputs:
  external_cert_path: '<this node local certificate path>'
  external_key_path: '<this node local private key path>'
  internal_cert_path: '<this node local certificate path>'
  internal_key_path: '<this node local private key path>'
  ca_cert_path: '<local CA certificate path>'
  external_ca_cert_path: '<local CA certificate path>'

prometheus:
  credentials:
    username: 'monitoringusername'
    password: 'longyeteasytorememberstringasapassword'

  cert_path: '<this node local certificate path>'
  key_path: '<this node local private key path>'
  ca_path: '<local CA certificate path>'

services_to_install:
  - manager_service
  - monitoring_service
  - entropy_service

Then, run cfy_manager install -c /etc/cloudify/manager_config.yaml --verbose.

After Cloudify Management service is installed on all three nodes, verify that the cluster looks healthy with running on one of them: cfy cluster status.

Day 2 Commands

Running day 2 (post installation) cfy_manager commands will require specifying the appropriate config.yaml file using the -c flag. For example:

Listing the DB cluster members: cfy_manager dbs list -c /etc/cloudify/db_config.yaml
Listing the RabbitMQ cluster members: cfy_manager brokers list -c etc/cloudify/rabbitmq_config.yaml.