Scheduled network software maintenance
A longer weekly window for scheduled IMP software maintenance.
Walden, D.C., "Scheduled network software maintenance", RFC 440, DOI 10.17487/RFC0440, January 1973, <https://www.rfc-editor.org/info/rfc440>.
@misc{rfc440,
series = {Request for Comments},
number = 440,
howpublished = {RFC 440},
publisher = {RFC Editor},
doi = {10.17487/RFC0440},
url = {https://www.rfc-editor.org/info/rfc440},
author = {D.C. Walden},
title = {{Scheduled network software maintenance}},
pagetotal = 1,
year = 1973,
month = jan,
} RFC text
Network Working Group David C. Walden
RFC #440 BBN-NET
NIC #13772 January 1973
Updates: 381,406
Scheduled Network Software Maintenance
--------------------------------------
As explained in RFC 381, we believe that we can minimize
the disruption caused by the release of new IMP software systems by
doing them on a regularly scheduled basis. In the past we have
reserved the one hour period from 7am until 8am every Tuesday morning
for our IMP system scheduled software maintenance period. As the size
of the network has grown to about forty IMPs, we find we can no longer
complete a system release to all IMPs in the one hour scheduled.
Therefore, we are extending our scheduled software maintenance period
to two hours from 7am until 9am eastern time every Tuesday
morning. The extended period will take effect as of the first Tuesday
in February. As we said in RFC 381, we will not always use the
Tuesday morning period, but we always reserve it. On Tuesday mornings
when we _do_ use the scheduled software maintenance period, a type 2 IMP
to Host message* will be sent to all Hosts about an hour in advance of
the period.
We understand that the software maintenance period cannot
continue to grow linearly with the number of IMPs, and we will find a
way around this problem before software releases start taking 168
hours a week.
*An IMP-GOING-DOWN-FOR-SCHEDULED-SOFTWARE-MAINTENANCE message.
[ This RFC was put into machine readable form for entry ]
[ into the online RFC archives by Alex McKenzie with ]
[ support from GTE, formerly BBN Corp. 9/99 ]
ISO Plain Language
On this page
§1Why the Window Is Extended
BBN says scheduled software releases are intended to minimize disruption. The previous Tuesday window ran from 7 a.m. to 8 a.m. Eastern time.
With the network grown to about forty IMPs, BBN could no longer complete a system release to all IMPs in that one-hour period.
BBN needed more time to update software on all the IMPs. The previous one-hour window was no longer enough.
§2The New Tuesday Window
The scheduled software-maintenance period is extended to two hours, from 7 a.m. until 9 a.m. Eastern time every Tuesday morning. The extension takes effect on the first Tuesday in February.
As before, the period is reserved every Tuesday but will not necessarily be used every week.
Two hours are now reserved for software maintenance every Tuesday morning. BBN may leave the window unused when no release is needed.
§3Notice to Hosts
On a Tuesday when the maintenance period will be used, Hosts receive a type 2 IMP-to-Host message about an hour before the period. The RFC identifies it as an IMP-GOING-DOWN-FOR-SCHEDULED-SOFTWARE-MAINTENANCE message.
BBN notes that the maintenance period cannot continue to grow linearly with the number of IMPs and says it will find another approach before releases require 168 hours per week.
Hosts receive an advance message when a scheduled software window will be used. BBN also recognizes that continually lengthening the window would not work indefinitely.