Posted in: Heart Internet
Here at Heart Internet we get very excited about new technology - often that’s software, but as the resident hardware geek on the team, I get excited about servers! Dell released their 12th Generation server line this year, and we’ve been deploying them across the platform for the last few months. Whenever new hardware is released, we go through a process of learning about the new hardware, testing it with our build processes and applications, getting an idea of its capacity and then deploying it into the live environment. This is quite a long process, so we’re very glad that Dell only release new generations of servers every 3 years or so; there are tweaks within generations but rarely anything too substantial.
For those of you thinking “3 years?! But I have to buy a new PC every 6 months to keep up!”, know this: the server market is very different from the domestic PC market; it’s geared towards stability, security and predictability. Boring, perhaps, but exactly what you want from the servers that are running your website 24/7 - each new generation of servers has been through a process of integration to help ensure that we don’t encounter driver issues, bottlenecks or incompatibilities that would threaten our uptime. Plus, we have machines out there with 48 CPU cores across 4 Xeon CPUs, half a TB of RAM and 16 disks in RAID-10; in 3 years that’ll still be a fantastic machine!
So, what’s cool about the new servers? Here goes!
AES-N-what-now? AES-NI. Intel have recently started shipping CPUs with on-die support for AES - one of the most popular encryption algorithms in use at the moment, and one that’s widely used on the Internet for serving pages over SSL. AES-NI reduces the number of clock cycles requires to process AES jobs by nearly 75%, meaning that we can deliver SSL traffic even faster than before. We’ve always aimed to minimise the overhead of using SSL on our platform, and this is a massive bonus for us.
As an industry, we’re moving towards more, smaller disks rather than fewer, larger ones. As a result, we’re now building servers with up to 26 2.5” disks in a 2U server, giving us tremendous i/o gains. Although costs per TB for data storage have plummeted, no real improvements in throughput have followed - a single spindle still spins at 15k and delivers about the same amount of data as it did 3 years ago. Although better caching strategies have negated this to an extent, getting data off magnetic disks is slow - more disks = more spindles = more i/o. Simple!
This is one of the best features we’ve seen in a long time. Typically, to improve performance, RAID cards will instantly return success to the OS when a write request is made (meaning that the OS can carry on with its operations), and then store the data in cache until a suitable time comes for the write to be made; typically when the disk has spun up and the head is in the right area of the disk to conveniently do the write. The problem with this is that if the power fails, the data is lost - so a battery is typically provided to protect the data. However, it doesn’t take much for a battery to fail - a loose connection, a nicked cable, and suddenly your cache has gone. Flash-backed cache means that as soon as the power goes, the contents of the cache are written to flash memory so the RAID card can be moved between servers or have its battery disconnected without fear of losing any data.
RAM. Lots of RAM
More RAM can only be better; we use a lot of memory-accelerated applications and the 12G servers pack more RAM into a faster configuration than before.
As a company, we’re very conscious of the impact that we have on the environment. Servers use a lot of power, keeping them cool uses a lot of power, and keeping them connected uses a lot of power. Reduction is better than offsetting (although we offset as well), and so we’re excited that the 12G servers are designed with efficiency in mind, and across the board we’re seeing lower power consumption, less heat production (hence less cooling) and smarter use of resources to make the most of every kWh we consume.