Performance improvements - Made the bitcoind_throttle facility (introduced in Fulcrum 1.0.4) behave in a peppier and more efficient manner when the server is not under load.
Resiliency - A new max subscriptions facility has been added to make it nearly impossible for abusive clients to degrade performance for normal clients.
max_subs_per_ip has been added as a conf file variable. Default is 50000 if unspecified. If the number of subscriptions from a particular IP address exceeds this value, new subscription requests are denied from that IP until its client(s) unsubscribe or disconnect. Note that clients belonging to subnets_to_exclude_from_per_ip_limits are not subjected to this limit.
max_subs has also been added as a conf file variable. Default is 10000000 (10 million) if unspecified. This is a limit on the number of subscriptions the server will allow, server-wide, for all clients. If this limit is reached, the server will take measures to potentially kick the most-offending client(s) that it detects.
Interoperability - Added 7 new RPC methods to make interoperability with scripting easier.
All the new methods live alongside the existing methods but they now accept addresses instead of script hashes, and all are prefixed with: blockchain.address.*
These work identically to their blockchain.scripthash.* counterparts, but can be given Bitcoin Cash addresses (rather than the esoteric script hash).
These methods increase interoperability of this server software with various clients that may or may not have a full bitcoin scripting lib to translate Bitcoin Addresses -> script hashes.
Both of the above binaries contains Qt5Core and Qt5Network from Qt 5.14.1 statically linked. They still requires libz2, libstd++, and the right libc version as dynamic libs on your system (but those are usually present if you are on a recent system).
If the first binary fails, try the second one (-ub16), which should work on older systems, hopefully.