At present (DBMaster 4.16/4.20), DBMaker allows the maximum of the command handles is 257.  But after 4.21, 4.22, 4.3 and later version, customer can set a configuration keyword – db_mxcmd in server side to enlarge this limitation.  The default is 257, and the range is 1 ~ 32767.  If you set this keyword too big, DBMaster should allocate more memory internally.  Please consider your application used handle.  Allocating too many handles will influence the performance in OS or Database.