[HECnet] SETNOD, Part 2

On 2021-05-31 20:50, Thomas DeBellis wrote: I was wondering if anybody would care to explain how routine node maintenance happens for DECnet on non-Tops-20 systems. Specifically, Johnny's node list on MIM:: changes more or less about once a month, sometimes more, sometimes less. Is anybody keeping up on this? How? I had a (bi-weekly) re-occurring batch job which NFT'ed the latest node file from MIM:: and simply used SETNOD to shove the whole thing into the running monitor, on the assumption that the monitor would figure out what to do. While slapping in the whole list (with .NDINT) during timesharing did strike me as somewhat wasteful, I didn't pay much attention to the matter as it did work. This is mistaken. Tops-20 will not 'make it' work, nor does it apparently detect certain situations which appear to be problematic. It does detect and reject two situations. 1. You may not change either the name or address of the host (I.E., the Executor). These can only be set once at boot up. Do other operating systems have this restriction? 2. You may not change the address of an existing node in the local area. A node insertion in the local area which usurps an address of another node deletes that node. Outside of the local area, you are on your own. It does whatever you want, which means that you can have multiple nodes with the same address. Is that a problem? On IP4, this would been known as 'aliasing', but I don't think DECnet allows this. So it would appear that the appropriate behavior is that a new node list implies a system reboot. Unless I'm actively doing monitor development, I can't stand doing this. However, fixing the problem turned out to be pernicious. Neither of the two cases above is reported to the user program; there is no way to determine what might have gone wrong. There is no way for the user program to proactively prevent errors because, while you can ask Tops-20 to translate a DECnet address to a node name and to verify that a DECnet node name exists, there is no way to return the address for a verified DECnet node name. Is this an oversight? Can a user program get the address of a DECnet node name on other operating systems? I remediated the low level error reporting issue and implemented a new function for NODE% to return the address of an existing DECnet node (.NDVFX or Verify Node Extended). Fixing SETNOD proved impossible. I discovered that the actions to be performed were complex enough when automated that the dimensions of the solution were wholly beyond its capabilities. Not that there was anything wrong with SETNOD, it just wasn't designed for this kind of heavy lift. So I rewrote it from scratch (cleverly naming it SETND2). I'm converging on completion, but I don't work on it actively, so this will probably be a few more weeks. Here is some sample output; let's suppose that BOINGO needs its address changed from 2.399 to 2.400 and that this conflicts with another node (in this case, APOLLO). To get this to work right, what you need to do is tell Tops-20 to do is delete BOINGO first, so that there is no name clash on the insertion. Then you have to delete APOLLO, so that there is no address conflict. Once you are done performing both these actions, it's safe to do the insertion and Tops-20 doesn't reject it or otherwise get itself confused. @*setnd2* % Insufficient capabilities for INSERT command SETNODE>*vERBOSITY* (level is) *vERBOSE * Verbosity level is VERBOSE SETNODE>*get /sECTION-MAP /nO-ACCESS* [BIN file: TOMMYT:<SYSTEM>NODE-DATA.BIN.91;RESTRICTED-JFN:13 ] Mapped one section (4 pages), 1778 Words, 889 Nodes. SETNODE>*recONSTRUCT /sILENT * [Closed log file: NUL:] SETNODE>*shoW aREA 2 uNCHANGED* [Area 2] A2RTR ADAGIO ADVENT ADVNT5 AMAPUR APOLLO AUG11 AUGVAX BASSET BEAGLE BELLS BOINGO BOXER BULDOG CHARON CODA COLLIE CONDOR CORGI COYOTE CYPHER DALMTN DIVISI DOGPAK ELIDYR ELITE FOX GLDRTR GLOVER GRUNT HERMES HUIA HUNTER HUSKY JACKAL JENSEN KELPIE LABRDR LAPDOG LARGO LEGATO LENTO MASTIF MENTOR MEZZO MULTIA MUTT NO0K ODST OINGO OSIRIS PAVANE POCO POODLE PUG PUGGLE PUPPY R2X899 REACH SPARK TERIER THEARK TOMMYT VENTI WLFHND WOLF ZITI Total nodes in area 2: 67 SETNODE>*shoW **uNCHANGED boiNGO* BOINGO:: (2.399) SETNODE>*set 2.400 boingo* Set existing node BOINGO:: (2.400) Node BOINGO:: (2.400) % Removing node BOINGO:: (2.399) from same list to insert in the delete list % Re-using key text for insertion in delete list, BOINGO (2.399) % Removing BOINGO::'s previous address (2.399) % Removing node APOLLO:: (2.400) from same list to insert in the delete list % Re-using key text for insertion in delete list, APOLLO (2.400) % Deleting APOLLO:: (2.400) to reassign its address to BOINGO:: % Allowing update request for node BOINGO:: (2.400) because being deleted as (2.399) % Removing node BOINGO:: (2.399) from unchanged list because its address has changed to (2.400) % Re-using key text for insertion in update list, BOINGO (2.400) Node change request for BOINGO:: (2.400) SETNODE>