High Availability

High Availability

Architecture

                    ┌──────────────┐
                    │  Load Balancer│
                    │  (HAProxy)    │
                    └──┬─────────┬──┘
                      │         │
                ┌─────▼───┐ ┌───▼──────┐
                │ NOC-01  │ │ NOC-02   │
                │ (Active)│ │ (Standby)│
                └─────────┘ └──────────┘
                      │         │
                ┌─────▼─────────▼──────┐
                │  Shared Storage (NFS) │
                └──────────────────────┘

Component Strategies

Component	Strategy
Traefik	Active-passive + keepalived VIP
MariaDB	Master-slave replication
OpenSearch	Multi-node cluster (3+ nodes)
Grafana	Active-passive, shared SQLite on NFS
Prometheus	Active-passive with Thanos sidecar
Redis	Redis Sentinel

MariaDB Replication

# On master
CREATE USER 'replica'@'%' IDENTIFIED BY 'replica_password';
GRANT REPLICATION SLAVE ON *.* TO 'replica'@'%';
SHOW MASTER STATUS;

# On slave
CHANGE MASTER TO MASTER_HOST='<master_ip>',
  MASTER_USER='replica', MASTER_PASSWORD='replica_password',
  MASTER_LOG_FILE='mariadb-bin.000001', MASTER_LOG_POS=<position>;
START SLAVE;

OpenSearch Cluster

Add multiple nodes to docker-compose.yml with discovery.seed_hosts and cluster.initial_master_nodes configured.

VIP with Keepalived

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 100
    virtual_ipaddress { 10.0.0.100/24; }
}

Shared Storage (NFS)

# On NFS server
apt-get install nfs-kernel-server
echo "/srv/nfs/opennoc <NOC_NETWORK>(rw,sync,no_subtree_check)" >> /etc/exports

# On NOC nodes
mount -t nfs <NFS_SERVER>:/srv/nfs/opennoc /var/lib/docker/volumes

---

Full reference: docs/ha/