Commit d3dbafa80b "Use blocking IO in P2P to reduce CPU load" (merged
into v2.1.0) introduced the constant IO_TIMEOUT, setting it to 1 second.
On nodes with high-latency connections, this short timeout causes the
txhashset archive download during step 2 of the IBD process to
invariably fail before it completes. Since there's no mechanism for
resuming a failed download, this means the node gets stuck at this stage
and never syncs.
Increasing IO_TIMEOUT to 10 seconds solves the issue on my node; others
might suggest a more optimal value for the constant.
mmgen
928097ad62