[ubuntu-uk] regarding for solution
Dear all, I have one problemI couldnt find right answer...do you have any idea? please please let me know many thanks fatma Consider the behaviour of two machines in a distributed system. Both have clocks that are supposed to tick 1000 times per millisecond. One of them ticks 990 times per millisecond. The other ticks 1015 times per millisecond. If the system designer want to guarantee that clocks of these two machines never differ by more than 5 seconds, how often must be clocks be re-synchronized? Supposing that all machines in this distributed systems come from same manufacturer and the maximum drift rate is specified as 1.0%, how often must the clocks of this system must be re-synchonized if the system designers want to guarantee that clocks of these two machines never differ by more than 5 seconds? Describe in steps how you get your result... _ Txt a lot? Get Messenger FREE on your mobile. https://livemessenger.mobile.uk.msn.com/ -- ubuntu-uk@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.kubuntu.org/UKTeam/
Re: [ubuntu-uk] regarding for solution[Scanned]
Hi, I'm not 100% sure but this would make sense as the first answer to me: the machine with 990 ticks should be experiencing time at (990/1000) of real time the machine with 1015 ticks should be experiencing time at (1015/1000) of real time The length of time it would take the two systems to go out of sync be 5 seconds would be: (1015/1000)a - (990/1000)a = 5 where a is the time needed between syncs so answer is 200 seconds Sorry, but the I've not really got time to work out the second one right now. I'll try and get back to it at some point if someone hasn't beaten me to it ;-) Thanks Paul fatma oymak wrote: Dear all, I have one problemI couldnt find right answer...do you have any idea? please please let me know many thanks fatma Consider the behaviour of two machines in a distributed system. Both have clocks that are supposed to tick 1000 times per millisecond. One of them ticks 990 times per millisecond. The other ticks 1015 times per millisecond. If the system designer want to guarantee that clocks of these two machines never differ by more than 5 seconds, how often must be clocks be re-synchronized? Supposing that all machines in this distributed systems come from same manufacturer and the maximum drift rate is specified as 1.0%, how often must the clocks of this system must be re-synchonized if the system designers want to guarantee that clocks of these two machines never differ by more than 5 seconds? Describe in steps how you get your result... _ Txt a lot? Get Messenger FREE on your mobile. https://livemessenger.mobile.uk.msn.com/ -- Paul Brunt Web Developer [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] DDI +44 (0) 1279 719584 Stortford Hall Industrial Park Dunmow Road, Bishops Stortford, Hertfordshire, CM23 5GZ United Kingdom www.armourhe.co.uk Tel +44 (0) 1279 50 Fax +44 (0) 1279 501080 This message (including any attachments) is confidential and may be privileged. It is intended solely for the use of the individual or entity to whom they are addressed. If you are not the intended recipient, please e-mail the sender immediately by replying to this message and delete the material from any computer. Armour Home Electronics Ltd shall not be liable for the improper or incomplete transmission of the information contained in this communication nor for any delay in its receipt or damage to your system. Armour Home Electronics Ltd does not guarantee that the integrity of this communication has been maintained nor that this communication is free of viruses, interceptions or interference. This message is attributed to the sender and may not necessarily reflect the view of Armour Home Electronics Ltd. -- ubuntu-uk@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.kubuntu.org/UKTeam/
Re: [ubuntu-uk] regarding for solution
fatma oymak wrote: Dear all, I have one problemI couldnt find right answer...do you have any idea? please please let me know many thanks fatma Consider the behaviour of two machines in a distributed system. Both have clocks that are supposed to tick 1000 times per millisecond. One of them ticks 990 times per millisecond. The other ticks 1015 times per millisecond. If the system designer want to guarantee that clocks of these two machines never differ by more than 5 seconds, how often must be clocks be re-synchronized? Supposing that all machines in this distributed systems come from same manufacturer and the maximum drift rate is specified as 1.0%, how often must the clocks of this system must be re-synchonized if the system designers want to guarantee that clocks of these two machines never differ by more than 5 seconds? Describe in steps how you get your result... Part 1: At least every 200 seconds - the difference between them gets .025 seconds (25 milliseconds) bigger each tick, so it will take 200 seconds for them to be 5 seconds apart (at which point the fast clock will read 202.02 is, and the slow clock will read 197.04 ish) Part 2: Consider the pathalogical case of variance, where one over-ticks by 1% and one under-ticks by one percent, so once is at 990 ms and the other at 1110 ms - hence the divergence is 20ms per tick... so it takes 250 ticks to diverge by five seconds. The third clock is irrelevant, since it has to be somewhere either at one of these extremes, or between them, so will never read further apart than the two pathalogical outliers. As an implementation issue, assuming that this can somehow be made Ubuntu-related, I'd sync each every minute with a crontab job :-) Mark -- ubuntu-uk@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.kubuntu.org/UKTeam/
Re: [ubuntu-uk] regarding for solution[Scanned]
Paul Brunt wrote: Hi, I'm not 100% sure but this would make sense as the first answer to me: the machine with 990 ticks should be experiencing time at (990/1000) of real time the machine with 1015 ticks should be experiencing time at (1015/1000) of real time The length of time it would take the two systems to go out of sync be 5 seconds would be: (1015/1000)a - (990/1000)a = 5 where a is the time needed between syncs so answer is 200 seconds Sorry, but the I've not really got time to work out the second one right now. I'll try and get back to it at some point if someone hasn't beaten me to it ;-) Thanks Paul Paul, I was in the middle of typing mine when yours came in, so as far as I'm concerned, you've won, particularly given we came up with the same answer :-) However, I'll claim the prize for part 2 :-) M. -- ubuntu-uk@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.kubuntu.org/UKTeam/
Re: [ubuntu-uk] regarding for solution
On Wed, 2007-05-16 at 14:43 +0100, fatma oymak wrote: Dear all, I have one problemI couldnt find right answer...do you have any idea? please please let me know Haha. 1 point for effort for getting other people to do your school/college/uni assignments - minus 10 points to everyone who has answered so far :) Cheers, Al. signature.asc Description: This is a digitally signed message part -- ubuntu-uk@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.kubuntu.org/UKTeam/
Re: [ubuntu-uk] regarding for solution
Haha. 1 point for effort for getting other people to do your school/college/uni assignments - minus 10 points to everyone who has answered so far :) Cheers, Al. I didn't think anyone else had noticed :-P Chris -- ubuntu-uk@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.kubuntu.org/UKTeam/
Re: [ubuntu-uk] regarding for solution
Chris Rowson wrote: Haha. 1 point for effort for getting other people to do your school/college/uni assignments - minus 10 points to everyone who has answered so far :) Cheers, Al. I didn't think anyone else had noticed :-P Chris I had: You have to admire her initiative in posting here, and it's no 'worse' than googling for an answer really. Baz -- ubuntu-uk@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.kubuntu.org/UKTeam/
Re: [ubuntu-uk] regarding for solution
Alan Pope wrote: On Wed, 2007-05-16 at 14:43 +0100, fatma oymak wrote: Dear all, I have one problemI couldnt find right answer...do you have any idea? please please let me know Haha. 1 point for effort for getting other people to do your school/college/uni assignments - minus 10 points to everyone who has answered so far :) Cheers, Al. Plus 20 for the respondents who tried to bring in an Ubuntu reference to their answers :-) Plus 100 for those who realise that it's important to meet people new to the community on their terms, and reel them in gently :-) :-) Plus 1000 for those who try to turn this into a what do students what out of Linux - free answers to their homework thread :-) :-) :-) Minus 5000 for those who try to come up with a list of increasingly valuable points reasons to justify their having answered.. DAMN! M. -- ubuntu-uk@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.kubuntu.org/UKTeam/
