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We cut our Mongo DB costs by 90% by moving to Hetzner

prosopo.io

11–20 of 214 posts

Re: We cut our Mongo DB costs by 90% by moving to Hetzner

#11

"We replaced a cluster of virtualized servers with a single bare metal server. Nothing has gone wrong, yet."

Lol yep that could've been the headline. We plan to add replica servers at some point. This DB is not critical to our product hence the relaxed interim setup.

Re: We cut our Mongo DB costs by 90% by moving to Hetzner

#14
How long does mongodump take on that database? My experience was that incremental filesystem/blockdevice snapshots were the only realistic way of backing up (non sharded) mongodb. In our case EBS snapshots, but I think you can achieve the same using LVM or filesystems like XFS and ZFS.

Re: We cut our Mongo DB costs by 90% by moving to Hetzner

#15
post #5

> The more keen eyed among you will have noticed the huge cost associated with data transfer over the internet - its as much as the servers! We're building Prosopo to be resilient to outages, such as the recent massive AWS outage, so we use many different cloud providers. I mean, you're connecting to your primary database potentially on another continent? I imagine your costs will be high, but even worse, your perfor…

> I mean, you're connecting to your primary database potentially on another continent?

Atlas AWS was actually setup in Ireland. The data transfer costs were coming from extracting data for ML modelling. We don't get charged for extracting data with the new contract.

> experts in a domain that maybe is out of your depth

We're in the bot detection space so we need to be able to run our own infra in order to inspect connections for patterns of abuse. We've built up a fair amount of knowledge because of this and we're lucky enough to have a guy in our team who just understands everything related to computers. He's also pretty good at disseminating information.

Thanks for reading!

Re: We cut our Mongo DB costs by 90% by moving to Hetzner

#16

Always consider if 12 hours of lost revenue is worth the savings. Recently hetzner has been flakey with minimum or no response for support or even status updates that anything was wrong. My favorite was them blaming an issue on my side just to have a maintenance status update the day after about congestion.

Using hetzner since 5 years never had issues and only 1 downtime in one data center.

Re: We cut our Mongo DB costs by 90% by moving to Hetzner

#17
> Here's how we managed to cut our costs by 90%

You could cut your MongoDB costs by 100% by not using it ;)

> without sacrificing performance or reliability.

You're using a single server in a single datacenter. MongoDB Atlas is deployed to VMs on 2-3 AZs. You don't have close to the same reliability. (I'm also curious why their M40 instance costs $1000, when the Pricing Calculator (https://www.mongodb.com/pricing) says M40 is $760/month? Was it the extra storage?)

> We're building Prosopo to be resilient to outages, such as the recent massive AWS outage, so we use many different cloud providers

This means you're going to have multiple outages, AND incur more cross-internet costs. How does going to Hetzner make you more resilient to outages? You have one server in one datacenter. Intelligent, robust design at one provider (like AWS) is way more resilient, and intra-zone transfer is cheaper than going out to the cloud ($0.02/GB vs $0.08/GB). You do not have a centralized or single point of failure design with AWS. They're not dummies; plenty of their services are operated independently per region. But they do expect you to use their infrastructure intelligently to avoid creating a single point of failure. (For example, during the AWS outage, my company was in us-east-1, and we never had any issues, because we didn't depend on calling AWS APIs to continue operating. Things already running continue to run.)

I get it; these "we cut bare costs by moving away from the cloud" posts are catnip for HN. But they usually don't make sense. There's only a few circumstances where you really have to transfer out a lot of traffic, or need very large storage, where cloud pricing is just too much of a premium. The whole point of using the cloud is to use it as a competitive advantage. Giving yourself an extra role (sysadmin) in addition to your day job (developer, data scientist, etc) and more maintenance tasks (installing, upgrading, patching, troubleshooting, getting on-call, etc) with lower reliability and fewer services, isn't an advantage.

Re: We cut our Mongo DB costs by 90% by moving to Hetzner

#18
post #8

Always consider if 12 hours of lost revenue is worth the savings. Recently hetzner has been flakey with minimum or no response for support or even status updates that anything was wrong. My favorite was them blaming an issue on my side just to have a maintenance status update the day after about congestion.

Atlas wasn't giving us any support for $3K per month. Hetzner at least have some channel to contact them, which is an improvement. That said, if their uptime is rubbish them we'll probably migrate again. Moving back to Atlas is not an option as we were getting hammered by the data transfer costs and this was only going to increase due to our architecture. Thanks for reading!

OVH is allegedly pretty good. I host all my personal stuff on Hetzner right now so I can't speak to it personally.

Re: We cut our Mongo DB costs by 90% by moving to Hetzner

#20

You probably want to store the backup somewhere else, ie. not Hetzner. They are known to just cancel accounts and cut access.

Any proof of that? I am a Hetzner customer and had never heard of this before. Would be good to know what I got into.
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