3 ms·

I have heard this anecdote before. In case you might not: 51days is awfully close to 2^32ms ...

by choeger 7y ago

dan_quixote 7y ago
Just for good measure: (2^32)/(1000 * 3600 * 24) = 49.71 days
- sedatk 7y ago
  so the correlation is meaningless here, as the reboot time is after the overflow.
  - CyanBird 7y ago
    It could very easily be that some manager decided to add an extra day to the schedule "just in case" as in close enough
  - SAI_Peregrinus 7y ago
    2^32 * 1024us is 50.9 days.
creato 7y ago
This must be a coincidence because surely there is a large safety factor in this 51 day schedule. If the reboot is required to be every 51 days, surely the issue this is trying to avoid only appears after at least 3-4x as long.
- close04 7y ago
  > This AD requires repetitive cycling of the airplane electrical power. This AD was prompted by a report that the stale-data monitoring function of the common core system (CCS) may be lost when continuously powered on for 51 days The issue appears after 51 days. I can't see in that AD a specific recommendation to reboot at predetermined intervals, just that it requires reboots before 51 days of continuous operation.
dpau 7y ago
there was also a conjecture that the dreamliner required rebooting every 248 days due to a similar issue https://www.engadget.com/2015-05-01-boeing-787-dreamliner-software-bug.html https://www.engadget.com/2015-05-01-boeing-787-dreamliner-so...
JadeNB 7y ago
tpmx (https://news.ycombinator.com/item?id=22761698 https://news.ycombinator.com/item?id=22761698) points out a related anecdote https://sites.google.com/site/edmarkovich2/whywindows95andwindows98wouldcrashafter49.7daysofuptime https://sites.google.com/site/edmarkovich2/whywindows95andwi... .
ndespres 7y ago
The 51 days in the headline popped out to me because I have a Sonicwall brand firewall I help manage which requires a reboot every 51 days or it starts dropping packets. Yesterday was day 51 and like clockwork, it started failing.
SAI_Peregrinus 7y ago
2^32 * 1024us is 50.9 days. So it's probably a systick at 1.024ms overflowing a uint32_t.

I have heard this anecdote before. In case you might not: 51days is awfully close to 2^32ms ...

dan_quixote 7y ago

Just for good measure: (2^32)/(1000 * 3600 * 24) = 49.71 days

sedatk 7y ago
so the correlation is meaningless here, as the reboot time is after the overflow.
- CyanBird 7y ago
  It could very easily be that some manager decided to add an extra day to the schedule "just in case" as in close enough
- SAI_Peregrinus 7y ago
  2^32 * 1024us is 50.9 days.

creato 7y ago

This must be a coincidence because surely there is a large safety factor in this 51 day schedule. If the reboot is required to be every 51 days, surely the issue this is trying to avoid only appears after at least 3-4x as long.

close04 7y ago
> This AD requires repetitive cycling of the airplane electrical power. This AD was prompted by a report that the stale-data monitoring function of the common core system (CCS) may be lost when continuously powered on for 51 days The issue appears after 51 days. I can't see in that AD a specific recommendation to reboot at predetermined intervals, just that it requires reboots before 51 days of continuous operation.

dpau 7y ago

there was also a conjecture that the dreamliner required rebooting every 248 days due to a similar issue https://www.engadget.com/2015-05-01-boeing-787-dreamliner-software-bug.html https://www.engadget.com/2015-05-01-boeing-787-dreamliner-so...

JadeNB 7y ago

tpmx (https://news.ycombinator.com/item?id=22761698 https://news.ycombinator.com/item?id=22761698) points out a related anecdote https://sites.google.com/site/edmarkovich2/whywindows95andwindows98wouldcrashafter49.7daysofuptime https://sites.google.com/site/edmarkovich2/whywindows95andwi... .

ndespres 7y ago

The 51 days in the headline popped out to me because I have a Sonicwall brand firewall I help manage which requires a reboot every 51 days or it starts dropping packets. Yesterday was day 51 and like clockwork, it started failing.

SAI_Peregrinus 7y ago

2^32 * 1024us is 50.9 days. So it's probably a systick at 1.024ms overflowing a uint32_t.