Advanced High Availability

Annex Cloud cloud-based infrastructure is designed to be highly available. All servers and network devices have redundant components and multiple network paths to avoid single points of failure.

Production application servers are load balanced within each region. Production database servers are replicated in near-real time to a peer data center within the same geographic region in Europe, North America, and Asia-Pacific.

In the event of the failure of one or more infrastructure components, service is restored by transferring the operation of an application associated with the failed components to the peer data center.


Global Data Center Pairs

Annex Cloud infrastructure is arranged in pairs. Our cloud infrastructure pairs span three continents: Asia, Europe, North America. All customer production data is stored in both data centers and kept in sync using real-time database replication. Both data centers are active at all times.

Annex Cloud maintains continuous, asynchronous replication from the database in the current primary data center (read-write) to the secondary data center (read-only). To transfer application instances from a primary to a secondary data center, Annex Cloud designates the secondary to be the primary and the primary to be the secondary.

  • . Multiple web farms (each comprising of web servers, database servers, firewall, cache etc.) in the same zone/region to share load
  • . Auto-scaling with both scaling up and out on both web and database nodes
  • . Dynamic load balancing for both web and database nodes


The Annex Cloud aims to be always operational for our customers. No vacation, no extended upgrade or maintenance windows, no single points of failure. We focus on near-perfect availability with redundancy built in to every layer of our cloud, including redundant devices, all network and server infrastructure. There is no downtime necessary for upgrades. Real Availability is the true measure of customer availability by looking at every incident that results in a customer outage (a Priority 1 or P1 incident).

  • . Redundant nodes available and ready to take over during failover within clusters
  • .Real-time availability and heartbeat monitoring with failover
  • .99.9% monthly uptime Percentage “Service Commitment” across all regions of the world


Our Cloud scales to meet the needs of the enterprises and aims to be always operational for our customers. We have hundreds of customers operating globally in our cloud regions. Each of our customer instances leverages our multi-tenant architecture to perform an aggregate of tens of millions of full page transactions every month. Scalable caching layer (Redis) to reduce database load Global CDN and edge-caching used to reduce web load Architected to allow for client caching for key data and call AC only for updates/real-time needs.

Database Backup and Recovery

While Advanced High Availability is the primary means to recover data and restore service in the case of a disruption, in certain cases it is desirable to use Annex Cloud’s more traditional data backup and recovery mechanism. It works in concert with AHA and acts as a secondary recovery mechanism. The backup cycle consists of daily full backups of 30 days and the past seven days of daily differential backups. All backups are written to disk, no tapes are used and no backups are stored in different regions. All the controls that apply to live customer data also apply to backups. If data is encrypted in the live database, then it will also be encrypted in the backups. Regular, automated tests are run to ensure the quality of backups. Any failures are reported for remediation within Annex Cloud. Real time off-zone and region data backups are performed.

Database Backup and Recovery

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