Happy 2454466.5! (Jan 02 2008)


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Profile Matt Lebofsky
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Message 696817 - Posted: 2 Jan 2008, 22:54:11 UTC

Happy new year! Actually, being that every moment is the beginning of some arbitrarily defined era, I should be more clear: Happy new calendar year number 2008, whoever uses this particular calendar system which I usually do!

The weekend was busy with the more-and-more-common fast workunits. Discussions today at the lab brought up the fact that about a third of our data will translate into these fast runners, so we better turn our attention back towards improving the data pipeline. We picked two low hanging fruits today: convert server bane from a redundant web server to a secondary download server. This will help determine if that bottleneck is the server or the storage. I also added a flag to the splitter scripts to select files in beam/polarization pair order, not filename order. This will help pseudo-randomize the creation of work, and hopefully spread the pain of fast workunit periods so we aren't so overwhelmed at times.

Nevertheless, we have Astropulse coming down the pike, and have a lot of SETI@home data to go through (and we're starting to collect new data again!). So we need to upgrade the network/servers in a big way. And acquire more participants. Not sure how this will all happen yet, but it has to happen.

Meanwhile, we might try another science database index build tomorrow (or soon thereafter). Bob found a way to do so while the database is up and inserting rows, so we might not have to shut down splitters/assimilators during the long build. Cool.

- Matt

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Message 696824 - Posted: 2 Jan 2008, 23:10:02 UTC

Hope everyone at Berkeley had a pleasant holiday period and is back nice and relaxed?

Not that it would help much in the bigger picture but I added another 2 participants recently to help speed things along.

For your information as well, I am currently in the process of getting quotes etc for some new servers for the network I am Admin for at my place of work. I will hopefully if it is approved which I am hoping it would be, have a redundant server of equal or possible better spec than what you require for the Near Time Persistency Checker server. I will keep you informed and if it is approved, funding is available to purchase the new servers immediately.

Only set back would be getting them to you as I am located in Montreal, Canada.

Hope you have a great New Year everyone.






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Message 696839 - Posted: 3 Jan 2008, 0:07:11 UTC
Last modified: 3 Jan 2008, 0:07:49 UTC

I'm sure this is well known, but I can't recall it: what is the origin of this threads name (is it scientific or some do-wa-diddy tune?)

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Message 696842 - Posted: 3 Jan 2008, 0:17:04 UTC - in response to Message 696817.
Last modified: 3 Jan 2008, 0:19:24 UTC

snip...

The weekend was busy with the more-and-more-common fast workunits. Discussions today at the lab brought up the fact that about a third of our data will translate into these fast runners, so we better turn our attention back towards improving the data pipeline.

...snipped a bit more

And a happy new calender year to you and all the staff.

We thought you already knew that a third of all MB work was short units. We had already worked that out in October in the Optimised Apps Question thread, where numbers from mine (post 668556)and others computers indicated that these short units accounted for at least 30% of all units but only ~10% of crunching time.

Andy

edit] 2454466.5 is the Julian date for start of 2008

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Message 696852 - Posted: 3 Jan 2008, 0:40:48 UTC - in response to Message 696839.

I'm sure this is well known, but I can't recall it: what is the origin of this threads name (is it scientific or some do-wa-diddy tune?)



It's the Julian Day. :-)


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Message 696857 - Posted: 3 Jan 2008, 0:56:10 UTC - in response to Message 696839.

I'm sure this is well known, but I can't recall it: what is the origin of this threads name (is it scientific or some do-wa-diddy tune?)

To avoid having to deal with the irregularities in various calendars, astronomers often use a method for designating time called the Julian Date: it’s the exact number of days since noon UT on 1 January, 4713 B.C. The figure in the title corresponds to the moment the year 2008 began at Greenwich.

You’ll also sometimes see a Modified Julian Date, which is equal to the JD minus 2400000.5; this corresponds to the number of days since 0h UT on 17 November, 1858.

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Message 696875 - Posted: 3 Jan 2008, 2:02:40 UTC - in response to Message 696857.

"And acquire more participants"

it might help if you(seti) support an optimizer program, like the seti "classic" had. just trying to help
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Message 696884 - Posted: 3 Jan 2008, 3:07:00 UTC - in response to Message 696857.

I'm sure this is well known, but I can't recall it: what is the origin of this threads name (is it scientific or some do-wa-diddy tune?)

To avoid having to deal with the irregularities in various calendars, astronomers often use a method for designating time called the Julian Date: it’s the exact number of days since noon UT on 1 January, 4713 B.C. The figure in the title corresponds to the moment the year 2008 began at Greenwich.

You’ll also sometimes see a Modified Julian Date, which is equal to the JD minus 2400000.5; this corresponds to the number of days since 0h UT on 17 November, 1858.


Thanks for the info, but what on earth could have happened in 4713 BC to merit such significance, 7 millenia later?

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Message 696928 - Posted: 3 Jan 2008, 5:24:59 UTC - in response to Message 696875.

"And acquire more participants"

it might help if you(seti) support an optimizer program, like the seti "classic" had. just trying to help


BOINC has had the ability to use optimized science applications since it's first version. Much of the optimized code made it into the official SETI@Home application, optimizing much of it already at the stock level.
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Message 696945 - Posted: 3 Jan 2008, 6:12:00 UTC - in response to Message 696875.
Last modified: 3 Jan 2008, 6:12:23 UTC

"And acquire more participants"

it might help if you(seti) support an optimizer program, like the seti "classic" had. just trying to help

What's this?
Crunch3r's BOINC page

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Message 696958 - Posted: 3 Jan 2008, 6:58:31 UTC - in response to Message 696884.

Thanks for the info, but what on earth could have happened in 4713 BC to merit such significance, 7 millenia later?

I don’t remember the exact details, but several calendrical cycles (three IIRC, one of them being the 19-year Metonic period) coincided in that year. I believe there were also numerological considerations relating to the supposed date of the Nativity, whose serial numbers all ‘came out right’ given that starting point (which was only a little more than six millennia before the system was invented). Aside from long-standing tradition, one of the reasons this epoch continues to be useful is that it’s considerably earlier than any known written records, so all historical events can be expected to have a positive JD.

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Message 696962 - Posted: 3 Jan 2008, 7:21:27 UTC


Thanks for the Posting Matt - and A Happy New Year to You is in Order Sir!


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Message 696985 - Posted: 3 Jan 2008, 12:18:06 UTC - in response to Message 696884.

I'm sure this is well known, but I can't recall it: what is the origin of this threads name (is it scientific or some do-wa-diddy tune?)

To avoid having to deal with the irregularities in various calendars, astronomers often use a method for designating time called the Julian Date: it’s the exact number of days since noon UT on 1 January, 4713 B.C. The figure in the title corresponds to the moment the year 2008 began at Greenwich.

You’ll also sometimes see a Modified Julian Date, which is equal to the JD minus 2400000.5; this corresponds to the number of days since 0h UT on 17 November, 1858.


Thanks for the info, but what on earth could have happened in 4713 BC to merit such significance, 7 millenia later?


As far as I know it is due to a reverend who wanted to know when the universe started according to the Bible, so he started at year zero and read the old testaments adding up the years and we got the year 4713 BC as the beginning of the universe
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Message 696990 - Posted: 3 Jan 2008, 12:50:34 UTC - in response to Message 696985.

I'm sure this is well known, but I can't recall it: what is the origin of this threads name (is it scientific or some do-wa-diddy tune?)

To avoid having to deal with the irregularities in various calendars, astronomers often use a method for designating time called the Julian Date: it’s the exact number of days since noon UT on 1 January, 4713 B.C. The figure in the title corresponds to the moment the year 2008 began at Greenwich.

You’ll also sometimes see a Modified Julian Date, which is equal to the JD minus 2400000.5; this corresponds to the number of days since 0h UT on 17 November, 1858.


Thanks for the info, but what on earth could have happened in 4713 BC to merit such significance, 7 millenia later?


As far as I know it is due to a reverend who wanted to know when the universe started according to the Bible, so he started at year zero and read the old testaments adding up the years and we got the year 4713 BC as the beginning of the universe


Are you thinking of the Revd. Ussher? I think his answer was 4004 BC. But when I looked him up, I was surprised how many different answers there were. None of them 4173 BC!

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Message 697000 - Posted: 3 Jan 2008, 14:30:02 UTC - in response to Message 696990.

Are you thinking of the Revd. Ussher? I think his answer was 4004 BC. But when I looked him up, I was surprised how many different answers there were. None of them 4173 BC!

What?! He had a CPU named after his calculation?!

4004

All of 92000 operations per second. Those were the days!

Happy crunchin',
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Message 697029 - Posted: 3 Jan 2008, 17:18:21 UTC - in response to Message 696842.

We thought you already knew that a third of all MB work was short units...


I sort of did. I shoot these tech news items off rather quickly though still try to keep each tech news item as a separate whole (so people won't have to scan through to many previous threads) at the expense of being redundant or sounding like an idiot.

- Matt
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Message 697042 - Posted: 3 Jan 2008, 18:21:42 UTC

Matt

I think there maybe a problem with the way the splitters are running now.

It looks to me that splitters are set to process the same number of beams for each datafile. If you add a new datafile the splitters will attempt to have the number off beams split for the new file catch up with the number off beams split for the files already in the queue, resulting in several splitters working on the same (new) datafile. And this is equal to the old splitting setup.

The only way I can think off to prevent this is to run the splitter queue completely dry and then refill it with a new batch off datafiles.
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Message 697194 - Posted: 4 Jan 2008, 3:39:36 UTC - in response to Message 696985.
Last modified: 4 Jan 2008, 3:40:24 UTC

As far as I know it is due to a reverend who wanted to know when the universe started according to the Bible, so he started at year zero and read the old testaments adding up the years and we got the year 4713 BC as the beginning of the universe

The most famous such calculation was by the Irish primate James Ussher, but his result was 23 October, 4004 B.C.—and he had nothing to do with the Julian Date system. Its inventor was the French clergyman Joseph Scaliger; although his interests and motivations were similar, I don’t think went so far as to identify his –4712.0 epoch with the date of the Creation. And rather than relying exclusively on biblical sources, he apparently researched all kinds of ancient chronologies.

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Message 697722 - Posted: 5 Jan 2008, 20:33:28 UTC - in response to Message 696985.

As far as I know it is due to a reverend who wanted to know when the universe started according to the Bible

I'm surprised that nobody ever thought to present this question to Jesus back in the day... ;)
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