Viewing profile — eivanov89

Dear friends, I'm the author of this implementation. Happy to discuss details.

> Provocative thought in that case would then be - in what % are io_uring improvements (over libaio) undermined by the device behavior (firmware) in mixed workloads. That % could r…

When IOMMU is not enabled, any PCIe device capable of DMA could access arbitrary physical memory. It allows to read any sensitive data, modifying memory and fully compromising the …

We compared IOMMU fully disabled vs enabled. When it is enabled, I expect it to be lazy (should be the default for IOMMU). Note, that we recommend to use passthrough to completely …

There are a couple of challenges with mixed read+write workloads on NVMe. In practice, read latency tends to degrade over time under mixed load. We observe this even across relativ…

That's super hot. Especially the update with the 37M IOPS reference. Might be very useful for my next tasks related to a setup with 6 NVMe disks: 1. Get all disks saturated through…

BTW, the whole situation with IRQ accounting disabled reminds me the -fomit-frame-pointer case. For a long time there was no practical performance reason, but the option had been u…

Unfortunately, we don't have a proper measurements for IOPOLL mode with and without IOMMU, because initially we didn't configure IOPOLL properly. However, I bet that this mode will…

That's a popular DBMS pattern. We chosen writes over reads, because on many NVMe devices writes are faster and it is easier to measure software latency. I guess that in case of seq…

Dear folks, I'm the author of that post. A short summary below. We ran fio benchmarks comparing libaio and io_uring across kernels (5.4 -> 7.0-rc3). The most surprising part wasn’t…

That's indeed interesting, thank you for sharing.

To the extent of my knowledge, only forks like YugabyteDB make PostgreSQL truly distributed. Or you should switch to another DB.

Dear friends, I’m the author of this post and I’d love to hear your thoughts and discuss it here.

My post is a secondary research regarding potential issues with weak isolation levels. It includes a link [0] to an in-depth description of what happened to Flexcoin. Additionally,…

Sorry, might be that the title is a little bit inaccurate. However, the post indeed describes multiple cases, when attackers have stolen many BTC from the exchanges, because of the…

Hi there, I'm the author of the post. I'm happy to answer any questions and appreciate any feedback and experience shared.

I think Denis addressed this in his post: "Overall, as an engineer, you will never regret taking part in the development of a sharding solution. It’s a complex engineering problem …