37
votes
Accepted
How do you calculate the compound Service Level Agreement (SLA) for cloud services?
After reading Tensibai's excellent answer, I realised I used to be able to calculate this for network analysis purposes. I dug out my copy of High Availability Network Fundamentals by Chris Oggerino ...
- 11.6k
24
votes
How do you calculate the compound Service Level Agreement (SLA) for cloud services?
I'd take that as a math problem with the SLA being the probability of being OK.
In this case we can rely on probability rules to get an overall.
For your first case the probability that App Service (...
- 11.3k
20
votes
Accepted
How can I experiment with Cloud (Azure, AWS, Google, etc) without going broke?
The three major cloud platforms you mentioned have either free trials or a free tier; these all include spending and resource caps which prevent you from spending more than your free trial allows:
...
- 11.6k
14
votes
How can I experiment with Cloud (Azure, AWS, Google, etc) without going broke?
Emulate the cloud on your own hardware
Doing anything substantial with the free tier is challenging. But you probably have some hardware lying around that you can build your own minicloud on. If you ...
- 1,838
12
votes
Accepted
How to avoid "retry storms" in distributed services?
It depends on what you're trying to avoid.
If you are trying to avoid any service interuption of something which is a genuinely critical service (I'm thinking in terms of "people will die if my API ...
- 1,734
8
votes
How to avoid "retry storms" in distributed services?
One way of preventing these retry storms is by using backoff mechanisms.
From the Implement backoff on retry section of Google App Engine Designing for Scale guide:
Your code can retry on failure, ...
- 6,730
6
votes
How can I experiment with Cloud (Azure, AWS, Google, etc) without going broke?
There are quite a few services that offer 'free tiers' of some description to help new developers get started with a cloud platform without the cost you've mentioned.
AWS have quite a generous free ...
- 1,532
6
votes
Large number of host emulation
you create a Docker Swarm stack file:
---
version: '3.1'
services:
ubuntu:
image: ubuntu # or your custom Docker image
deploy:
replicas: 10000
Then, with docker stack you can ...
- 6,802
6
votes
How to shut down a stateless app gracefully?
kill -9 is used by the kernel to terminate stateful programs that are no longer responding (including to shutdown requests). To gracefully shut down a stateful app you would use kill -15 which ...
- 3,724
6
votes
What is a "mesh"?
The concept of service discovery works like this:
When a server, such as a database, starts up, it contacts a central registry and says Hi, I am a database, and these are my connection details.
Then ...
- 1,086
6
votes
Accepted
Is there one website that contains all relevant DevOps news and gets updated on a daily basis?
There is a protocol for this: RSS, Rich Site Summary. Technically, there are 3 protocols RSS, RSS2 and Atom, but most readers support all of them, and many servers mix RSS and RSS2 features.
First, ...
- 176
4
votes
Accepted
Defined start sequence of containers
https://forums.rancher.com/t/start-order-of-stack-containers/3106/9
We do not support depends_on, and neither does Docker in Swarm mode.
It is not a real solution to the problem anyway and leaves ...
- 13.1k
4
votes
Accepted
What is a "mesh"?
The metaphor of "mesh" is "many interconnected things". We might describe TCP/IP as a "mesh technology" as it is the technology that connects many things and performs useful services like resending ...
- 1,172
4
votes
Accepted
When is it not appropriate to use serverless technology such as AWS Lambda?
There is likely no general answer to this question, but some reasons to not consider Lambda (or other serverless platforms) include:
App requires a language which is not available (C++, Haskell, ...
- 201
3
votes
How to install a private managed Kubernetes on-premise?
Take a look at OpenShift container platform (https://www.openshift.com/products/container-platform/). They seem to provide on-premise options. You might want to start with OpenShift Origin - the ...
- 270
3
votes
Cheapest and easiest way to run a periodic Docker process
AWS offers fargate now, which is managed by them rather than being a service like ECS which you ran the servers for and they manage the control plane. Fargate is basically "serverless" ECS. You can ...
- 155
3
votes
How can I calculate costs of deploying 1000 instances of Drupal?
In reply to 'Would Amazon EC2 / Google / Azure be cheaper than having dedicated servers?'
I've done a lot of investigating into this and in every case they are NOT.
80 Linux servers running 24h/365 ...
- 31
3
votes
Accepted
Geographically, where are the travis-ci jobs run?
Where are the travis-ci servers located? Does travis-ci leverage AWS EC2?
According to this documentation, the servers are located in the USA and AWS EC2 is used as well.
Your code, depending on ...
- 13.1k
3
votes
Accepted
How to shut down a stateless app gracefully?
A stateless app can always handle kill -9?
Yes. But even a stateless app handles connections from the outside (or it would do nothing, really!). That is the issue here. If your app, say, some HTTP ...
- 4,866
3
votes
Accepted
availability calculation of a azure service fabric stateful application
Virtual Machine Scale Sets (VMSSs) don't have a SLA of their own:
Virtual Machine Scale Sets is a free service, therefore, it does not have a financially backed SLA itself. However, if the Virtual ...
- 11.6k
3
votes
When is it not appropriate to use serverless technology such as AWS Lambda?
I wrote a bit about this on my LinkedIn post which was based on the article by Andrea Passwater.
In brief, do not go serverless, if
You want complete control of the infrastructure and latest system ...
- 273
3
votes
Accepted
What makes a difference between high-cost cloud providers and low-cost ones?
@jasper, and welcome to DevOps SE!
While your statement can be confirmed by other voices, it's very hard to x-ray price policies of a company. It's a complex gameplay always driven by many factors ...
- 6,802
3
votes
Accepted
Which cloud region could have the fastest time for a docker image push?
TLDR
From cloud instance, just go push to docker hub; you will be routed to the best location automatically.
Full details
DockerHub is a massive scale and very critical global service. So, you ...
- 1,460
3
votes
Can large scale services use a public cloud managed database service?
Yes, it is certainly possible, but it entirely depends on the architectural design of the entire system. Separating application services into manageable components (i.e. microservices) is one approach ...
- 3,218
2
votes
CI/CD with a GPU cluster
Since you're talking about CI/CD I presume you have the possibility to automate the model trainings in those configurations. Let's call the scripts able to do that train_model_config_A, ...
- 6,730
2
votes
Cheapest and easiest way to run a periodic Docker process
You can mix the powerful of Zappa and Hug to convert your code in a serverless AWS Lambda function adding only a decorator to your python process main function
import hug
[...]
@hug.get('/...
- 21
2
votes
Cheapest and easiest way to run a periodic Docker process
The cheapest way is to use Heroku's Container Registry.
It's entirely free, easy to use and deploy (You don't even need the heroku CLI , just docker push your image to registry.heroku.com with your ...
- 1,759
2
votes
simulate SQL DB usage pattern of a typical cloud native web app with sysbench?
... [I] can't say what exact app (shop, historic info, social media, forum)
This makes this question very difficult to answer. This is because you have two basic types of queries:
OLTP and OLAP ...
- 3,724
2
votes
Is it possible to securely delete a file from a virtual disk in a cloud provider?
You can't really use those tools with ext3 anyway. Wipe manpage has a large note about it:
No secure deletion program that does filesystem-level calls can sanitize files on such filesystems, ...
- 11.3k
2
votes
Accepted
Availability/Reproducibility of Ubuntu Minimal as Docker image
The answer to the question "is there a Dockerfile for that, as well?"
https://github.com/tianon/docker-brew-ubuntu-core/tree/dist-amd64
Note their git branches contain the actual release build based ...
- 36
Only top scored, non community-wiki answers of a minimum length are eligible