Finding holes in the ledger history on an XRPL server
An archive export needs every ledger from 710 through 730. An endpoint can hold both boundary ledgers and still lack part of the requested history.
Read the ranges the server actually holds
Post the JSON body to the HTTP RPC endpoint. Read result.info.complete_ledgers as a list of closed intervals. For an illustrative value of 700-715,720-740, heights 716 through 719 are missing even though the server has ledger 710 and ledger 730.
{"method":"server_info","params":[{}]}
Assign each portion of the export
Read 710–715 and 720–730 from this server. Send 716–719 to a server that advertises that entire interval, and keep the missing interval visible in the job until all four records arrive. If a load balancer chooses a different backend on each request, a successful range check can describe a different disk than the following read. Probe the backend used by the export or record which server returned each error.