Meltdown Patch Slows Down Performance On AWS

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The CPU catastrophe has hit. And it has hit the cloud the hardest. Amazon has confirmed that the unprecedented processor flaw has resulted in slowdown for some customers.

This, after the customers themselves complained about performance issues on their cloud workloads.

While the general feeling was that the problem was under control, and users would not be seeing too much of performance degradation after applying the patch for the CPU exploits, it apparently is not the case.

The patches that Intel has rushed out for the Meltdown chip flaw are actually affecting the performance of AWS EC2 instances — dramatically at that.

Customers are complaining about the performance hit, saying that it is hampering the performance of their applications. Online forums are brimming with users talking about the software fixes that have been made available to Windows, Linux, and macOS PCs and servers that run on Intel CPUs.

Basically, the patch that was rolled out in December has resulted in an increase in CPU utilization on EC2 virtual machines. Customers are being forced to either choose between optimizing their application code or to move to more powerful hardware to compensate for the slowdown.

Which is, in most cases is anywhere between 5% to 30%.

Nevertheless, an Amazon employee responded to the criticism from customers, saying:

“The update that is being applied to a portion of EC2 instances can, in some corner cases, require additional CPU resources … For some time we have recommended that customers use our latest generation instances with HVM AMIs to get the best performance from EC2. If moving to a HVM based AMI is not easy, changing your instance size to m3.medium, which provides more compute that m1.medium at a lower price may be a workaround.”

Amazon says that the patch should not impact most customer workloads, but for those that are feeling the effects, the company will work with them to resolve problems. Of course, the patch not only affects AWS, but other public clouds like Microsoft Azure and Google Compute Engine too.

Meltdown does not affect chips designed by AMD, but its server market share is so low that it practically does not matter.