Tenaya (Feb 24 2009) |
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Message boards : Technical News : Tenaya (Feb 24 2009)
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Had our weekly maintenance outage today, including the usual chores. I took the opportunity to replace a failed drive on one of our administrative file servers. I also issued the long-overdue final "shutdown" command on another administrative server, kang, which we no longer use. Many years ago, during the early days of SETI@home, several Sun representatives came by one day to discuss our progress. We thought it was just an informal touching-base kind of meeting, but they told us at the end they were going to donate a whole rack full of 6 state-of-the-art Sun servers and 2 disk arrays. Sun has always been nice to us, but this was completely unexpected. We eventually dubbed this the "k-rack" as we named every server after a sci-fi character starting with "k" (kang, kodos, kosh, klaatu, kryten, koloth). Well, kang, was the last one to go - the end of an era. We're still using the rack itself, though - very useful. | |
| ID: 869143 · | |
...One major issue is that our server closet (roughly 100 CPUs, 100 TB disk, 200 GB RAM) operates atomically - it's all or nothing. We can't just move one piece somewhere else. It's long and complicated - please don't make me explain why unless there's a free pitcher of beer involved. Matt: If I'm ever in Berkeley, or you're ever in Northern Virginia, I'd be happy to buy a pitcher and listen to you... C ____________ Join Team MacNN | |
| ID: 869149 · | |
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PM me your address and what type, and I will ship you what you want...beer, wine, etc. in an amount equal to a pitcher... | |
| ID: 869156 · | |
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Seeing the constant issues with bandwidth, I was wondering if the SETI data packets could be compressed (to reduce size for transfer), then BIONIC decompress for processing. | |
| ID: 869177 · | |
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Matt-thanks for the news and thoughts. You and Eric (and Angela of course) are always welcome for a visit. | |
| ID: 869179 · | |
Seeing the constant issues with bandwidth, I was wondering if the SETI data packets could be compressed (to reduce size for transfer), then BIONIC decompress for processing. File compression works based on the fact that the data in those files (word processing, databases, etc.) are not entirely random. A "flat file" database may compress 90% because one filler character appears over and over. Common bytes get shorter codes, uncommon bytes longer, and the average number of bits/character goes down. (gross oversimplification) Binary data consisting almost entirely of noise is going to be equally distributed across the whole range, so they aren't very compressable. ____________ | |
| ID: 869213 · | |
It's long and complicated - please don't make me explain why unless there's a free pitcher of beer involved. I'll happily send beer without the explanation. ____________ | |
| ID: 869214 · | |
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I'll be glad to help drink the beer. | |
| ID: 869216 · | |
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Free beer? | |
| ID: 869229 · | |
Free beer? Minus your cut of course. ____________ BOINC WIKI | |
| ID: 869233 · | |
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Free beer...tell me where and when and this old navy veteran will join you for whatever you want to give away. Darn I even will buy. GO ...GO...US Navy. | |
| ID: 869238 · | |
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hello from France | |
| ID: 869256 · | |
Seeing the constant issues with bandwidth, I was wondering if the SETI data packets could be compressed (to reduce size for transfer), then BIONIC decompress for processing. To put some rough numbers on it: Astropulse WUs compress less than 2% because the data is sent as true binary and the xml header information is relatively short. S@H Enhanced WUs compress around 27% because the data is packed 6 bits per byte, there are line feeds inserted after each 64, and the xml header is larger. That's gzip compression, IINM the download servers can be configured to apply that and libCurl can then ungzip the received data. If so, the effect might be similar to adding nearly 15 Mbits/sec of download bandwidth (assuming vader and bane wouldn't choke doing the extra calculations). Joe | |
| ID: 869257 · | |
Of course there are other options, too, like putting all efforts into final data analysis and shutting down SETI@home. No!! You can do that.. What else will my computers do all day every day? Other projects suck, this is by far the best one even with all the problems. ____________ | |
| ID: 869260 · | |
Would it not be cheaper to lease a server closet, properly equiped , How would the data get from Berkeley (where it is created in manageable chunks from the raw telescope recordings) to your ISP's server? That's why Matt said One major issue is that our server closet (roughly 100 CPUs, 100 TB disk, 200 GB RAM) operates atomically - it's all or nothing. We can't just move one piece somewhere else. @ Matt, We don't usually do pitchers in England, but I'd love to hear the stories - if you're ever in Yorkshire, these are waiting for you: | |
| ID: 869278 · | |
One major issue is that our server closet (roughly 100 CPUs, 100 TB disk, 200 GB RAM) operates atomically - it's all or nothing. We can't just move one piece somewhere else. Any possibility of teaming up with another university research group? That might reduce some of the hardware stress, but I don't know how feasible this might be. Just another option to toss out. As always, please keep us posted on the situation. ____________ <<Photo: ISS & Shuttle Discovery on STS-116 parting ways>> The SETI@home distributed cluster is listening. | |
| ID: 869286 · | |
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I'd say the best out of the three solutions is the 1Gbit link up to the server closet. | |
| ID: 869294 · | |
And a dyed-in-the-wool Lancastrian would risk crossing the border to double the contribution. F. ____________ | |
| ID: 869299 · | |
And I'll come across from Nottinghamshire to triple the contribution. Claggy ____________ | |
| ID: 869311 · | |
Add another 4 from Cambridgeshire :). Mick | |
| ID: 869334 · | |
Message boards : Technical News : Tenaya (Feb 24 2009)
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