Main > Everything Else
Workflow server
lilshawn:
--- Quote from: MonMotha on March 19, 2013, 11:22:37 am ---If I had to guess, you're bottlenecked on disk IO on the server. I've got 6 Xen domains running on a server nowhere near that capable CPU-wise (and less memory, and probably less memory bandwidth, too), and my bottleneck is ALWAYS the darned spinning metal. Lots of simultaneous requests for distinct files like you describe will easily get you well into seek hell. Throw an SSD at the thing if you can, and your problems will probably get better.
Failing that, upgrade the server's link to the LAN to 10Gb or 4xGbE. Make sure you've got a real switch, not some crummy Linksys thing.
Of course, real stats are always king. Instrument the heck out of the setup and see where your problems actually are.
--- End quote ---
i would have to agree. "the herd is only as fast as it's slowest member"
depending on the setup, your disk IO is only going to be a single IO operation at a time. Times that by 6 computers doing it a thousand times each at the same time that's 6000 IO's that have to be served. the server spends more time backlogged with IO requests.
I'm thinking spreading the load out to multiple controllers and disks can reduce this, being that data will be coming from multiple sources.
sdweim85:
Everyone is running at Gigabit speeds.
But yes, everyone's requests are coming off a single HDD.
The resource monitor shows a major slowdown in bandwidth alone. The CPU and memory are barely touched when everyone is viewing thumbnails over the network simultaneously.
That's expected though, since when they are viewing the thumbnails over the network, the file is writing to their desktop PC. So the server hardware isn't doing much except the HDD itself, and the NIC card.
We also tested Hyper-V Virtual machines with 3 VMS loading up Thumbnails all at the same time directly on the server. It was faster than doing it over the network, but its still a lot of stress on one HDD. Probably leading to the same issue. Using the network method puts the stress on the desktop PCs rather than the server.
kahlid74:
--- Quote from: sdweim85 on March 19, 2013, 04:02:05 pm ---But yes, everyone's requests are coming off a single HDD.
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Only one HDD? Ummm yeah, the red light is going off. You need to go past bandwidth monitors and look at metrics. Compare Busy time on the disk to Avg Queue Length and Current Queue Length.
lilshawn:
miliseconds of access time for a disk, times thousands and thousands of requests = FOREVER to get your info. sure a couple of miliseconds doesn't sound like much, but multiply that times a billion operations and it REALLY adds up.
I'd consider a RAID0 or RAID1 setup. you would see a HUGE gain in your output speeds, and it's pretty easy to set up.
MonMotha:
...or an SSD. I realize you may have a large amount of data, but the IOPS on even a mid-range SSD will blow a fairly fancy RAID0 array out of the water and probably be more reliable, too (though a big RAID6 array is probably even better in the reliability department, it'll take quite a large number of disks to match the SSD's performance on random access).