TL;DR: High availability (HA) refers to systems designed to stay online and responsive with minimal downtime, even when individual components fail. In blockchain infrastructure, HA means your RPC endpoints, nodes, and data pipelines keep serving requests reliably, typically targeting 99.9% uptime or higher.
Why Uptime Matters More Than You Think
When a traditional web app goes down, users see an error page. When blockchain infrastructure goes down, the consequences can be far more severe. Missed transactions, stale data, failed trades, and unprocessed events don't just frustrate users. They cost real money.
Consider a DeFi trading bot that relies on an RPC endpoint to submit transactions. If that endpoint goes offline for even 30 seconds during a volatile market move, the bot misses the window entirely. Or think about a wallet app that can't fetch balances because its node provider is experiencing an outage. Users don't know if their funds are safe, and your support queue explodes.
High availability is the engineering discipline that prevents these scenarios. It means designing systems where no single failure takes everything offline.
How High Availability Works
At its core, HA is about eliminating single points of failure. Instead of relying on one server, one data center, or one cloud provider, a highly available system distributes its workload across multiple redundant components.
In blockchain infrastructure, this typically involves several layers. The first is geographic distribution, where nodes are spread across multiple regions so that if one data center has an issue, traffic automatically routes to the nearest healthy alternative. The second is multi cloud deployment. Running on more than one cloud provider (and sometimes bare metal) ensures that a cloud specific outage doesn't take down your entire stack. The third is load balancing, which distributes incoming RPC requests across a pool of healthy nodes, automatically routing around any that are slow or unresponsive. The fourth is health monitoring, where automated systems continuously check node health, block height, and response times, flagging problems before they affect users.
