5 ms·

Want an example of "simple but less reliable"? Here's one (in one or two easy steps): 1. All updates go in to memcached, but not the database 2. (optional) A

Want an example of "simple but less reliable"? Here's one (in one or two easy steps): 1. All updates go in to memcached, but not the database 2. (optional) A background process occasionally copies entries from memcached to the db. Without this, the values will be completely lost when memcached restarts. Paul - here's an interesting take on your recommended solution: Use solid state ram and forget about step two. You get fast a read/write, without the risk of data loss if the machine restarts. Here's a pretty cool board that will take DDR SDRAM, and supply it with a constant source of power (imitating solid-state memory): http://techreport.com/reviews/2006q1/gigabyte-iram/index.x?pg=1 http://techreport.com/reviews/2006q1/gigabyte-iram/index.x?pg=1 Those who insist on a database, could even store the database on this board. Best of both worlds. Here's an insane graph showing the database transaction rate for the board vs. a conventional hard drive: http://techreport.com/reviews/2006q1/gigabyte-iram/index.x?pg=7 http://techreport.com/reviews/2006q1/gigabyte-iram/index.x?pg=7

aristus 20y ago
Solid-state drives greater than 128GB are in OEM testing now. Expect server economics to turn upside-down in about 12 months, when persistent storage seek times get 100X faster.
- paul 20y ago
  Yeah, solid-state storage is clearly the future for most apps. Flash is over 10x cheaper than DRAM though, so it'd be nice to see some high-performance flash drives as well. It's also nice to not have to worry about losing data during a prolonged power outage.
  - aristus 20y ago
    No need to wait, really. Addonics' SATA/CF adapters for your $80/8GB flash cards cost $35. Even cheap compact flash does random seeks 40x faster than platters. Throughput is a little slow but what the hell, for 115 bucks? If I were building a server farm right now I'd try those things out.
    - mattculbreth 20y ago
      This is a cool thread. So please spec out a couple servers for us. How would you get a bunch of memory (32GB, 64GB even) into one of them and still have it be a good web/app server?
      - aristus 20y ago
        My current favorite is the Altus 600 from Penguin Computing. Cheap chassis with dual sockets and 16 RAM slots. More slots means cheaper chips. 2GB chips for that board are about 300 bucks. Throw two 2.2GHz Opterons and 2x 300GB drives in there. Add an SATA controller card, 4 SATA/CF adapters and CF cards (in the CD-ROM bay), and you've got a nice machine: 1U, dual processors, 32GB of RAM, 600GB of platter, 32GB of flash for about USD$7500. Expensive, yeah. 5 grand of that is RAM. You could get away with 4GB of RAM and still have a fucking fast web/app server as long as your active dataset fits on the flash.
        paul 19y ago
        $215: http://www.newegg.com/Product/Product.asp?Item=N82E16820134302&ATT=20-134-302&CMP=OTC-pr1c3watch http://www.newegg.com/Product/Product.asp?Item=N82E168201343... Brings the memory cost down to around $3440.
        aristus 19y ago
        Wrong speed but yeah, that's the ballpark. I used Crucial to price the RAM.
    - paul 19y ago
      It's too bad that the transfer rate is so low. It should be pretty simple to build a very fast device which spreads the blocks across a large number of flash cards. I suppose you could do a raid array of addonics adapters, but it's unclear how that would perform (and it might be a mess dealing with a large number of them).
      - 19y ago
  - nostrademons 19y ago
    There's also the i-RAM ( http://techreport.com/reviews/2006q1/gigabyte-iram/index.x?pg=1 http://techreport.com/reviews/2006q1/gigabyte-iram/index.x?pg=1 ), a battery-backed RAM disk. My employer uses it for an app where disks simply couldn't deliver the latency we needed, and yet it had to be fault tolerant enough to survive a power failure. Edit: wow, totally did not see Sam_odio's original post, linking to exactly the same product. Oops. And yCombinator doesn't allow us to delete comments...

aristus 20y ago

Solid-state drives greater than 128GB are in OEM testing now. Expect server economics to turn upside-down in about 12 months, when persistent storage seek times get 100X faster.

paul 20y ago
Yeah, solid-state storage is clearly the future for most apps. Flash is over 10x cheaper than DRAM though, so it'd be nice to see some high-performance flash drives as well. It's also nice to not have to worry about losing data during a prolonged power outage.
- aristus 20y ago
  No need to wait, really. Addonics' SATA/CF adapters for your $80/8GB flash cards cost $35. Even cheap compact flash does random seeks 40x faster than platters. Throughput is a little slow but what the hell, for 115 bucks? If I were building a server farm right now I'd try those things out.
  - mattculbreth 20y ago
    This is a cool thread. So please spec out a couple servers for us. How would you get a bunch of memory (32GB, 64GB even) into one of them and still have it be a good web/app server?
    - aristus 20y ago
      My current favorite is the Altus 600 from Penguin Computing. Cheap chassis with dual sockets and 16 RAM slots. More slots means cheaper chips. 2GB chips for that board are about 300 bucks. Throw two 2.2GHz Opterons and 2x 300GB drives in there. Add an SATA controller card, 4 SATA/CF adapters and CF cards (in the CD-ROM bay), and you've got a nice machine: 1U, dual processors, 32GB of RAM, 600GB of platter, 32GB of flash for about USD$7500. Expensive, yeah. 5 grand of that is RAM. You could get away with 4GB of RAM and still have a fucking fast web/app server as long as your active dataset fits on the flash.
      - paul 19y ago
        $215: http://www.newegg.com/Product/Product.asp?Item=N82E16820134302&ATT=20-134-302&CMP=OTC-pr1c3watch http://www.newegg.com/Product/Product.asp?Item=N82E168201343... Brings the memory cost down to around $3440.
        aristus 19y ago
        Wrong speed but yeah, that's the ballpark. I used Crucial to price the RAM.
  - paul 19y ago
    It's too bad that the transfer rate is so low. It should be pretty simple to build a very fast device which spreads the blocks across a large number of flash cards. I suppose you could do a raid array of addonics adapters, but it's unclear how that would perform (and it might be a mess dealing with a large number of them).
    - 19y ago
- nostrademons 19y ago
  There's also the i-RAM ( http://techreport.com/reviews/2006q1/gigabyte-iram/index.x?pg=1 http://techreport.com/reviews/2006q1/gigabyte-iram/index.x?pg=1 ), a battery-backed RAM disk. My employer uses it for an app where disks simply couldn't deliver the latency we needed, and yet it had to be fault tolerant enough to survive a power failure. Edit: wow, totally did not see Sam_odio's original post, linking to exactly the same product. Oops. And yCombinator doesn't allow us to delete comments...