One more item on high availability with flash - folks ask should I replicate in the server? I usually recommend across servers and physical locations for the utmost availability.
Another good case study is a our customer Polaris, who took query times from 3 minutes (with frequent time outs) to an average of 2-3 seconds. This included full HA with SIOS DataKeeper. http://www.fusionio.com/blog/polaris-sios/
anytime you can remove bottlenecks you can speed up the system. faster transactions and faster logging with flash, coupled with flash-to-flash replication for HA brings performance up and costs down.
The legacy IO protocols were design for magnetic spinning disk, and designed to ensure integrity of disk writes. Within the protocol are n-phase commits, which require multiple exchanges. Moving to flash as an extension of DRAM would simplify...
... atomic writes are part of the T10 submissions and can achieve this. In HA, the data could be written to flash directly on one system in parallel with data being sent to another server and being written to flash on the second system
and another one. What in-house/default tool you suggest for benchmarking the iops. blktrace of Jens Axobe is what I have used extensively on disk based environment. Is it same for flash or anything else?
in general we recommended benchmarking at the application transaction level. sometimes people talk about using iometer and I joke "do you run your business on iometer?" :)
Soham Chakraborty Okay, now the tough part is whenever users face a bottleneck they think it is either storage or OS. Coming from Linux background, it is quite troublesome to let them explain about app level. Then question, what metric on app level :)
one of the creative stats I saw last week from eBay was URLs per Kilowatt. they really narrowed down what mattered up top (pages served) with costs on the bottom (electricity)
HA choices can be a strategic weapon for CIOs. In the past, storage HA was the ONLY choice. Now you can choose that OR server layer. Means more negotiating power.
What is Fusion-IO’s thoughts on Sata Express? How will your company embrace this technology to promote widespread adoption of PCI Express SSDs? #Flash#Storage
SATA is great for disk drives and we use it extensively in our hybrid storage appliance. but for letting flash do what it does best, a PCIe based approach is best
interesting to note that apple promotes "PCIe-based flash" when you go to buy a Macbook. They are good indicators of where the industry is heading http://store.apple.com/us/buy-mac/macbook-pro
Considering a medium sized organization, how would you suggest going for a flash based HA architecture? HA being included in app and not being app are two conditions. #flash#haflash
Putting HA in the application layer gives the greatest flexibility and the lowest infrastructure cost. HA has to include data availability, integrity & recovery. Using flash as part of the storage can significantly help recovery times
If the HA is not included App, then using flash well in the storage layer can provide storage redundancy (replication) and provide fast recovery. This has to be done for legacy applications with no HA awareness.
2) another option is active-active controller architectures in the storage appliance itself...similar to our ioControl Hybrid Storage product http://www.fusionio.com/products/iocontrol
