Constant COMMITS_PER_FETCH_CEILING 

pub const COMMITS_PER_FETCH_CEILING: usize = 1024;

Ceiling on the commits a commit-sync fetch may request, for regular and fast commit sync alike. A client requests at most its own commit_sync_batch_size or fast_commit_sync_batch_size commits, both validated against this at startup. Enforced while decoding each response message, before its entries are materialised.