Use the extfn_get_library_version method to extract the library version from the current multiplex node. The server considers partitioning a query across multiplex nodes only if the installed library is compatible with the other nodes.
size_t extfn_get_library_version( uint8 *buff, size_t len );
Library versioning methods are at the library level, and do not have the a_v4 prefix in their method name.
If the v4 library defines the optional entry point, the server allows query distribution to other nodes. The entry point populates the supplied buffer with the library version string (a C-style character string containing only ASCII characters, terminated with \0) and returns the actual size of the populated version string, which is constrained to a maximum of 256 bytes.
If an entry point is not defined, the server does not distribute the UDF to the other nodes in the multiplex.