[HECnet] SETNOD, Part 2

[Johnny Billquist]

Changing the name of the executor might be objected to by most systems...
Updating it with the same information it already have should (I hope) be 
a no-op.

With RSX, the nodename of the executor itself is special, and don't sit 
together with all to name to number associations for other nodes. So it 
don't really hit the executor when doing such a clear/purge. I think 
it's similar with VMS.

But my comment was mainly because the point brought up from Keith that 
other node information, such as various parameters for DECservers, are 
also in the database, and you don't want to delete that.
But the commands are "CLEAR NODE * NAME", which means only the name is 
deleted, not other type of information/parameters in the database. So 
DECserver information should not be touched in the first place.

   Johnny

On 2021-06-01 07:02, Thomas DeBellis wrote:
> True, but I don't believe you couldn't do that on a Tops-20 cluster.  At 
> best, it might not be a good idea.
> 
> No Tops-20 node on the CI will allow a name (or address) redefinition 
> for itself once booted.  The command would be rejected by the Executor.  
> You'd have the situation where nodes would have different definitions of 
> neighbors because each neighbor's Executor would no longer have the 
> neighbor's definition.  Or something like that...
> 
> At Columbia, if we had to do something like that, we brought the entire 
> cluster down.  This was *really* frowned on.
> 
> On 5/31/21 5:17 PM, Johnny Billquist wrote:
>> Well, the CLEAR/PURGE is only for the name, not any other information...
>>
>>   Johnny
>>
>> On 2021-05-31 23:04, Steve Davidson wrote:
>>> Unfortunately CLEAR/PURGE is not a good idea in clusters or nodes 
>>> that boot DECservers.  VMS requires additional information in the 
>>> database for those nodes/servers that would be wiped out. That is why 
>>> I wrote NETUPDATEV2.COM. It does the update without touching any 
>>> nodes in the local area.
>>>
>>> -Steve Davidson
>>>
>>> SF:iP1
>>>
>>>> On May 31, 2021, at 16:49, Keith Halewood 
>>>> <Keith.Halewood at pitbulluk.org> wrote:
>>>>
>>>> With VMS, it's also permissible to copy 
>>>> sys$system:netnode_remote.dat to other nodes, mainly because no 
>>>> executor information is contained within this file.
>>>> Dune::netupdatev3.com is a modified form of the update script which 
>>>> does a purge/clear by individual area, except for one's own area 
>>>> which is handled on a node by node basis, including a configurable 
>>>> range within that area which is ignored. For example, it prevents 
>>>> MIM:: from overriding 29.100-199 by default.
>>>>
>>>> Keith
>>>>
>>>> -----Original Message-----
>>>> From: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] 
>>>> On Behalf Of Johnny Billquist
>>>> Sent: 31 May 2021 20:48
>>>> To: hecnet at Update.UU.SE
>>>> Subject: Re: [HECnet] SETNOD, Part 2
>>>>
>>>> If there is some additional commands you'd like for me to put into 
>>>> FIX.T20, let me know.
>>>>
>>>> The VMS commandfile I creates starts like this:
>>>>
>>>> $ MCR NCP
>>>> PURGE NODE * NAME
>>>> CLEAR NODE * NAME
>>>> def nod 41.28 name 28NH
>>>> .
>>>> .
>>>> .
>>>>
>>>> Which means that any previous definitions are first cleared out 
>>>> before any definitions go in.
>>>> This is because VMS (and RSX) do not handle if you have a node name 
>>>> that gets a different address. Clearing things out first solves that.
>>>>
>>>> The alternate thing that can be done in VMS is that you can copy 
>>>> nodenames from within NCP from another node, which seems to avoid 
>>>> the problem as well (I think).
>>>>
>>>> In RSX, the permanent nodename database in RSX can be created by a 
>>>> separate tool that does not at all relates to the current nodename 
>>>> database, so in RSX it's rather easy. You download a new database, 
>>>> and then you switch it over to the new db.
>>>>
>>>> With other systems I don't know at all.
>>>>
>>>>    Johnny
>>>>
>>>>
>>>>> 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>
>>>>>
>>>>
>>>> -- 
>>>> Johnny Billquist                  || "I'm on a bus
>>>>                                    ||  on a psychedelic trip
>>>> email: bqt at softjar.se             ||  Reading murder books
>>>> pdp is alive!                     ||  tryin' to stay hip" - B. Idol
>>

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol