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Our new search index: Caffeine

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Re: Our new search index: Caffeine

#41

Post by iamelgringo »

houseabsolute wrote: post #30
blasdel wrote: post #27

Earlier quoted context omitted.

You think Google's mainline storage of their index is on disk ? It is to laugh. I don't think that's been true since around the time they stopped building server shelves out of lego or cardboard. They've been keeping the full text of the web in RAM (for the snippets), with indexes, several times over. With independent live siblings in multiple datacenters.

Well, the serving part of their index is in memory (or largely so) as has been publicly announced. But are you really suggesting they might do the same for indexing? Let's suppose for a second that they can get 8GB sticks of RAM for 1/3 the retail price of around $600, and for the sake of the back of the envelope calculation, let's round it up to ten GB. So let's call it $20/GB of RAM. Four gigabyte sticks might seem…

Why use RAM? You can get a 500GB SSD for $1000. 100 PB would cost you $200 Million, which is peanuts to Google.

Or you could use PCIe SSD drives. You can get a TB of PCIe for $3000, and a 5 PCIe x16 mother board at Fry's costs around $300. You could get 100PB of PCIe SSd storage for around $300 M.

You could use RAM for very fast cache, and SSD storage for faster than HDD indexing and retrieval.

Re: Our new search index: Caffeine

#42

Post by gojomo »

houseabsolute wrote: post #30
blasdel wrote: post #27

Earlier quoted context omitted.

You think Google's mainline storage of their index is on disk ? It is to laugh. I don't think that's been true since around the time they stopped building server shelves out of lego or cardboard. They've been keeping the full text of the web in RAM (for the snippets), with indexes, several times over. With independent live siblings in multiple datacenters.

Well, the serving part of their index is in memory (or largely so) as has been publicly announced. But are you really suggesting they might do the same for indexing? Let's suppose for a second that they can get 8GB sticks of RAM for 1/3 the retail price of around $600, and for the sake of the back of the envelope calculation, let's round it up to ten GB. So let's call it $20/GB of RAM. Four gigabyte sticks might seem…

The post wording "Caffeine takes up nearly 100 million gigabytes of storage in one database" isn't clear that's all needed for the constantly-consulted index; just that's what the indexing system uses, including perhaps rarely-consulted information. They might also be reporting uncompressed data sizes, or counting all the raw 'storage' used to store info in triplicate (or more).

So the live data consulted for almost all web queries might be be much much less than 100 PiB of index data, and thus fit far more economically in RAM.

Re: Our new search index: Caffeine

#43

Post by grrr45 »

Posted by Carrie Grimes, Software Engineer

Dr. Grimes currently leads a research & technical team in Search Infrastructure at Google and is actively trying to figure out what criteria make a search engine index "good," "fast," and "comprehensive."

Yeah, right. "Software Engineer" ? bullshit.

Re: Our new search index: Caffeine

#44

Post by houseabsolute »

iamelgringo wrote: post #41
houseabsolute wrote: post #30

Earlier quoted context omitted.

Well, the serving part of their index is in memory (or largely so) as has been publicly announced. But are you really suggesting they might do the same for indexing? Let's suppose for a second that they can get 8GB sticks of RAM for 1/3 the retail price of around $600, and for the sake of the back of the envelope calculation, let's round it up to ten GB. So let's call it $20/GB of RAM. Four gigabyte sticks might seem…

Why use RAM? You can get a 500GB SSD for $1000. 100 PB would cost you $200 Million, which is peanuts to Google. Or you could use PCIe SSD drives. You can get a TB of PCIe for $3000, and a 5 PCIe x16 mother board at Fry's costs around $300. You could get 100PB of PCIe SSd storage for around $300 M. You could use RAM for very fast cache, and SSD storage for faster than HDD indexing and retrieval.

$200M is still a quarter of their capital expenditure in 2009 not including the other parts of the machines. And before 2009 flash was much more expensive and not as fast as it is now. It would surprise me greatly to hear that they had gone this route.

Re: Our new search index: Caffeine

#45

Post by SkyMarshal »

grrr45 wrote: post #43

Posted by Carrie Grimes, Software Engineer Dr. Grimes currently leads a research & technical team in Search Infrastructure at Google and is actively trying to figure out what criteria make a search engine index "good," "fast," and "comprehensive." Yeah, right. "Software Engineer" ? bullshit.

She's more than a mere Software Engineer, she's a scientist. AB in Archeology/Anthropology from Harvard, then a PhD in Statistics from Stanford.

Very interesting background to bring to this field. Call it real-time statistical anthropology.

Re: Our new search index: Caffeine

#46

Post by houseabsolute »

drats wrote: post #40
houseabsolute wrote: post #30

Earlier quoted context omitted.

Well, the serving part of their index is in memory (or largely so) as has been publicly announced. But are you really suggesting they might do the same for indexing? Let's suppose for a second that they can get 8GB sticks of RAM for 1/3 the retail price of around $600, and for the sake of the back of the envelope calculation, let's round it up to ten GB. So let's call it $20/GB of RAM. Four gigabyte sticks might seem…

That link has over 7 billion of capex for 2006-2009 there without accounting for their earlier pre-2006 hardware. It's eminently feasible.

Most of that was during a time when RAM was significantly more expensive than my calculations took into account. But in any case, you and I are talking about two different things. You're saying that there is some possible universe where they are using 100 PB of ram on this project alone. I'm claiming that it's very unlikely that this is the same universe as the one we are living in. While I'll gladly admit that you are correct in your claim, I don't think it's useful.

Re: Our new search index: Caffeine

#47

Post by houseabsolute »

gojomo wrote: post #42
houseabsolute wrote: post #30

Earlier quoted context omitted.

Well, the serving part of their index is in memory (or largely so) as has been publicly announced. But are you really suggesting they might do the same for indexing? Let's suppose for a second that they can get 8GB sticks of RAM for 1/3 the retail price of around $600, and for the sake of the back of the envelope calculation, let's round it up to ten GB. So let's call it $20/GB of RAM. Four gigabyte sticks might seem…

The post wording "Caffeine takes up nearly 100 million gigabytes of storage in one database" isn't clear that's all needed for the constantly-consulted index; just that's what the indexing system uses, including perhaps rarely-consulted information. They might also be reporting uncompressed data sizes, or counting all the raw 'storage' used to store info in triplicate (or more). So the live data consulted for almost…

Right. That is why I distinguished between the serving data and the data they discussed in this post.

Re: Our new search index: Caffeine

#48

Post by orionlogic »

tptacek wrote: post #2

Wow is that ever a terrible infographic.

very much like itunes Genius bar logo with electrons changed with google sidebar icons.

Caffeine is not new and has been talked in SEO community from a quite sometime. I wonder why they make it public now.

To silence iPhone 4 news? No no,just coincidence...

Re: Our new search index: Caffeine

#49

Post by herdrick »

blasdel wrote: post #27
moe wrote: post #17

Earlier quoted context omitted.

On the other hand it doesn't seem that much when you consider todays storage density. You can fit around 0.5 PB into one rack nowadays. 200 racks then sounds a bit less impressive than 100 Petabytes. However, that ofcourse doesn't account for redundancy, nor for doing anything useful with such a pile of data. Both of which impose some interesting challenges at that scale.

You think Google's mainline storage of their index is on disk ? It is to laugh. I don't think that's been true since around the time they stopped building server shelves out of lego or cardboard. They've been keeping the full text of the web in RAM (for the snippets), with indexes, several times over. With independent live siblings in multiple datacenters.

No need to laugh. It was a reasonable assumption.
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