This got me thinking about the recent Rails improvement on moving cache from RAM to SSD. The test they did from what I remembered was RAM at 0.8ms and SSD was ~1.5ms. Moving to SSD you could afford to cache 10x more data and still be cheaper. Now I wonder if the test results would be the same on cloud. Assuming they tested it locally.
SSDs have become fast, except in the cloud
301–310 of 427 posts
Re: SSDs have become fast, except in the cloud
#302Earlier quoted context omitted.
The main problem with consumer drives is the missing power loss protection (plp). M.2 drives just don't have space for the caps like an enterprise 2.5 u.2/u.3 drive will have. This matters when the DB calls a sync and it's expecting the data to be written safely to disk before it returns. A consumer drive basically stops everything until it can report success and your IOPS falls to like 1/100th of what the drive is c…
My experience lately is that consumer drives will also lie and use a cache, but then drop your data on the floor if the power is lost or there’s a kernel panic / BSOD. (Samsung and others.)
Rumors of that. I've never actually seen it myself.
Re: SSDs have become fast, except in the cloud
#303This got me thinking about the recent Rails improvement on moving cache from RAM to SSD. The test they did from what I remembered was RAM at 0.8ms and SSD was ~1.5ms. Moving to SSD you could afford to cache 10x more data and still be cheaper. Now I wonder if the test results would be the same on cloud. Assuming they tested it locally.
They (Basecamp) recently moved off of cloud, so I’m wondering if they even care for their particular use case.
I’m sure this is configurable in general though?
Re: SSDs have become fast, except in the cloud
#304Earlier quoted context omitted.
vcpu performance is still locked to the typical core from 10 years ago No. In some cases I think AWS actually buys special processors that are clocked higher than the ones you can buy.
You are talking about real CPU not virtual cpu
Generally each vCPU is a dedicated hardware thread, which has gotten significantly faster in the last 10 years. Only lambdas, micros, and nanos have shared vCPUs and those have probably also gotten faster although it's not guaranteed.
Re: SSDs have become fast, except in the cloud
#305Re: SSDs have become fast, except in the cloud
#306Seeing the really just puny "provisioned IOPS" numbers on hugely expensive cloud instances made me chuckle (first in disbelief, then in horror) when I joined a "cloud-first" enterprise shop in 2020 (having come from a company that hosted their own hardware at a colo). It's no wonder that many people nowadays, esp. those who are so young that they've never experienced anything but cloud instances, seem to have little…
Some of us are making a good living offboarding workloads from cloud onto bare metal with on-node NVMe storage.
Re: SSDs have become fast, except in the cloud
#307This got me thinking about the recent Rails improvement on moving cache from RAM to SSD. The test they did from what I remembered was RAM at 0.8ms and SSD was ~1.5ms. Moving to SSD you could afford to cache 10x more data and still be cheaper. Now I wonder if the test results would be the same on cloud. Assuming they tested it locally.
got a link to the rails improvement?
nvm, found it: https://dev.37signals.com/solid-cache/
Re: SSDs have become fast, except in the cloud
#308This was a huge technical problem I worked on at Google, and is sort of fundamental to a cloud. I believe this is actually a big deal that drives peoples' technology directions. SSDs in the cloud are attached over a network, and fundamentally have to be. The problem is that this network is so large and slow that it can't give you anywhere near the performance of a local SSD. This wasn't a problem for hard drives, whi…
This is an interesting benchmark that compares disk read latency across different clouds across various disk configurations, including SSD's and EBS: https://github.com/scylladb/diskplorer
Google's disk perform quite poorly.
And how Discord worked around it: https://discord.com/blog/how-discord-supercharges-network-di...
Re: SSDs have become fast, except in the cloud
#309Earlier quoted context omitted.
For what kind of workloads would a slower SSD be a significant bottleneck?
I run very large database-y workloads. Storage bandwidth is by far the throughput rate limiting factor. Cloud environments are highly constrained in this regard and there is a mismatch between the amount of CPU you are required to buy to get a given amount of bandwidth. I could saturate a much faster storage system with a fraction of the CPU but that isn’t an option. Note that latency is not a major concern here. Thi…
Thanks for the details!
Does this mean you're colocating your own server in a data center somewhere? Or do you have your own data center/running it off a bare metal server with a business connection?
Just wondering if the TCO included the same levels of redundancy and bandwidth, etc.
Re: SSDs have become fast, except in the cloud
#310Earlier quoted context omitted.
I don't like this answer. When I look at cloud, I get to think "finally! No more hardware to manage. No OS to manage". It's the best thing about the cloud, provided your workload is amenable to PaaS. It's great because I don't have to manage Windows or IIS. Microsoft does that part for me and significantly cheaper than it would be to employ me to do that work.
> No more hardware to manage. No OS to manage We must be using different clouds. For some of the much higher-level services … maybe some semblance of that statement holds. But for VMs? Definitely not "no OS to manage" … the OS is usually on the customer. There might be OS-level agents from your cloud of choice that make certain operations easier … but I'm still on the hook for updates. Even "No machine" is a stretch,…
I'm baffled after you quoted 'no OS to manage' why you'd start discussing virtual machines.