Make a Solana readiness probe check the JSON-RPC result

A process can accept connections while its ledger falls behind. The health method compares the node’s progress with the cluster tip using its configured slot-distance threshold.

Parse the response body

Send this body by POST to the backend being tested. For a load-balanced deployment, check individual backends as well as the public hostname so one healthy replica cannot hide a lagging one.

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getHealth",
  "params": []
}

Accept the literal result string "ok". Keep HTTP errors, a JSON-RPC error object, and a request timeout as separate observations in the probe log. For example, a successful HTTP exchange with an error object shows that the RPC process answered, even though the readiness test failed.

Investigate a sustained failure

Compare the backend’s finalized slot over several checks against a trusted peer on the same cluster at the same commitment. Record whether the gap is growing or closing. Historical block availability and WebSocket delivery need separate probes that exercise those capabilities.

Documentation