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Checklist: what had to be done before deploying microservices to production

Reading time9 min
Views9.5K

This article contains a brief squeeze from my own experience and that of my colleagues, with whom I had been fighting incidents day and night. And many incidents would never have occurred if all these microservices that we love so much were written at least a little more carefully.


Unfortunately, some programmers seriously believe that a Dockerfile with any team at all inside is a microservice in itself and can be deployed even now. Dockers are running — money are incoming. This approach turns into problems starting from performance degradation, inability to debug, service failures and ending in a nightmare called Data Inconsistency.


If you feel that the time has come to launch one more app in Kubernetes / ECS / whatever, then I have something to object to.

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Total votes 20: ↑19 and ↓1+18
Comments1

A small notebook for a system administrator

Reading time21 min
Views161K
I am a system administrator, and I need a small, lightweight notebook for every day carrying. Of course, not just to carry it, but for use it to work.

I already have a ThinkPad x200, but it’s heavier than I would like. And among the lightweight notebooks, I did not find anything suitable. All of them imitate the MacBook Air: thin, shiny, glamorous, and they all critically lack ports. Such notebook is suitable for posting photos on Instagram, but not for work. At least not for mine.

After not finding anything suitable, I thought about how a notebook would turn out if it were developed not with design, but the needs of real users in mind. System administrators, for example. Or people serving telecommunications equipment in hard-to-reach places — on roofs, masts, in the woods, literally in the middle of nowhere.

The results of my thoughts are presented in this article.

Figure to attract attention
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Total votes 91: ↑88 and ↓3+85
Comments57

The authoritative guide to Blockchain Sharding

Reading time12 min
Views1.3K

Hi, I'm one of the developers of the sharded blockchain Near Protocol, and in this article want to talk about what blockchain sharding is, how it is implemented, and what problems exist in blockchain sharding designs.


It is well-known that Ethereum, the most used general purpose blockchain at the time of this writing, can only process less than 20 transactions per second on the main chain. This limitation, coupled with the popularity of the network, leads to high gas prices (the cost of executing a transaction on the network) and long confirmation times; despite the fact that at the time of this writing a new block is produced approximately every 10–20 seconds the average time it actually takes for a transaction to be added to the blockchain is 1.2 minutes, according to ETH Gas Station. Low throughput, high prices, and high latency all make Ethereum not suitable to run services that need to scale with adoption.

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Total votes 15: ↑14 and ↓1+13
Comments0

Monitoring System for Windows servers on pure SQL, and how I had secretly dragged it into the Production

Reading time5 min
Views1.3K
A long time ago in a galaxy far, far away there was a company grown from a startup to something much bigger, but for a while the IT department was still compact and very efficient. That company hosted on prem hundreds of virtual Windows servers, and of course these servers were monitored. Even before I joined the company, NetIQ had been chosen as a monitoring solution.

One of my new tasks was to support NetIQ. The person, who worked with NetIQ before, said a lot about his experience with NetIQ, unfortunately, if I try to put it here it would be just a long line of ‘****’ characters. Soon I realized why. Steve Jobs is probably spinning in his grave looking at the interface like this:

image
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Total votes 22: ↑21 and ↓1+20
Comments0

Writing yet another Kubernetes templating tool

Reading time8 min
Views12K


If you are working with Kubernetes environment then you probably make use of several existing templating tools, some of them being a part of package managers such as Helm or Ksonnet, or just templating languages (Jinja2, Go template etc.). All of them have their own drawbacks as well as advantages and we are going to go through them and write our own tool that will try to combine the best features.

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Total votes 22: ↑21 and ↓1+20
Comments1

Test me if you can. Do YML developers Dream of testing ansible?

Reading time3 min
Views3.5K

kitchen-ci schema


It is text version of the presentation 2018-04-25 at Saint-Petersburg Linux User Group. Configuration example locates at https://github.com/ultral/ansible-role-testing


I suppose that that you make configuration management, not bash. It means that you have to test it some how. Have you ever tested ansible roles? How do you do it?

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Total votes 18: ↑17 and ↓1+16
Comments2

How to test your own OS distribution

Reading time3 min
Views1.8K

intro


Russian version


Let's imagine that you are developing software and hardware appliance. The appliance consists of custom OS distributive, upscale servers, a lot of business logic, as a result, it has to use real hardware. If you release broken appliance, your users will not be happy. How to do stable releases?


I'd like to share my story how we dealt with it.

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Total votes 17: ↑15 and ↓2+13
Comments0

PVS-Studio for Java

Reading time12 min
Views2.5K
PVS-Studio for Java

In the seventh version of the PVS-Studio static analyzer, we added support of the Java language. It's time for a brief story of how we've started making support of the Java language, how far we've come, and what is in our further plans. Of course, this article will list first analyzer trials on open source projects.
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Total votes 31: ↑31 and ↓0+31
Comments2

PVS-Studio 7.00

Reading time6 min
Views3.9K
PVS-Studio C#\Java\C++Today is an important day — after 28 releases of the sixth version we present our PVS-Studio 7.00, in which the key innovation is the support of the Java language. However, during 2018 we have acquired many other important changes related to C++, C#, infrastructure and support of coding standards. Therefore, we bring to your attention a note that sums up the major changes that have happened in PVS-Studio for the last time.
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Total votes 52: ↑51 and ↓1+50
Comments3

What to think during NALSD interview

Reading time7 min
Views9.1K
There are a lot of posts about what a typical coding interview at Google looks like. But, while not as widely described and discussed, there is also quite often a system design interview. For an SRE position it’s NALSD: non-abstract large system design. The key difference between SWE and SRE interviews consists in these two letters: NA.

So, what is the difference? How to be prepared for this interview? Let’s be non-abstract, and use an example. To be more non-abstract, let’s take something from the material world, such that you won’t be asked the exact same thing at the real interview (at least, not at the Google interview) :)

So, let’s design a public library system. For the paper books, like you have seen everywhere around. The whole text below was written all at once within around one hour, to roughly show you the areas that you should be able to cover / touch during the interview. Please excuse some disorder, that’s how I think (therefore I am).
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Total votes 26: ↑24 and ↓2+22
Comments0

How to crack a self-service terminal and why 80% of them are under threat

Reading time2 min
Views2.9K
Author of the original post in Russian: frsamara

I always loved playing with things and testing them under all sorts of wacky conditions as a kid and even considered getting a job as a tester, but I never did. Nevertheless, I still like taking things made by someone else and poking them for vulnerabilities.

I remember, when first self-service payment terminals started popping around town, I saw one of them put up a browser window while updating, and the game was on — I broke it almost immediately. There’s been a lot of discussion about it since then and developers have started to pay a lot more attention towards security in these machines.

Recently, fast-food joints have started installing these terminals. Obviously, it’s quite convenient: just tap a couple of virtual buttons, place an order, pay with a bank card and wait for your number to show on the screen.

Also, nearly every big mall has these interactive boards with floor plans and information on various sales and discounts.

How secure are they?
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Total votes 13: ↑13 and ↓0+13
Comments1