Category Archives: HOWTO’s

Kubernetes: PVC in StatefulSet, and the “Forbidden updates to statefulset spec” error

22 July 2025
 

 We have a VictoriaLogs Helm chart with a PVC size of 30 GB, which is no longer enough for us, and we need to increase it. But the problem is that .spec.volumeClaimTemplates[*].spec.resources.requests.storage in STS is immutable, that is, we can’t just change the size through values.yaml file, because it will lead to the error“Forbidden: updates… Read More »

Kubernetes: what are the Kubernetes Operator and CustomResourceDefinition

21 July 2025
 

 Perhaps everyone has used operators in Kubernetes, for example, PostgreSQL operator, VictoriaMetrics Operator. But what’s going on under the hood? How and to what are CustomResourceDefinition (CRD) applied, and what is an “operator”? And finally, what is the difference between a Kubernetes Operator and a Kubernetes Controller? In the previous part – Kubernetes: Kubernetes APIs,… Read More »

TCP/IP: OSI and TCP/IP models, TCP packets, Linux sockets and ports

19 July 2025
 

  It’s difficult to describe in one post what thousands of books have been written about in a thousand pages, but today we’ll try to quickly review the basics of how hosts communicate on a network. First, let’s talk about the OSI and TCP/IP models, then about packet structure and connection establishment, and finally, we’ll… Read More »

VictoriaMetrics: fixing the “no matches for kind VMAnomaly” error

10 July 2025
 

  It’s not the first time I’ve encountered similar errors when upgrading VictoriaMetrics, so it’s time to note a solution. So, after upgrading the victoria-metrics-k8s-stack 0.55.0 => 0.56.0, errors appeared in the Operator logs: … {“logger”:”controller-runtime.source.EventHandler”,”msg”:”if kind is a CRD, it should be installed before calling Start”,”kind”:”VMAnomaly.operator.victoriametrics.com”,”error”:”no matches for kind \”VMAnomaly\” in version \”operator.victoriametrics.com/v1\””} …… Read More »

Arch Linux: linux-firmware-nvidia: /usr/lib/firmware/nvidia/ exists in filesystem

9 July 2025
 

  Even though the changes were announced in emails from Arch Linux, for some reason, many people have had problems with the latest update: in the Arch Linux subreddits on Reddit, people are complaining like “Everything is broken, what should I do now?” Let’s see how to complete the upgrade and what exactly has changed.… Read More »

VictoriaMetrics: migrating VMSingle and VictoriaLogs data between Kubernetes cluster

5 July 2025
 

 We have VictoriaMetrics and VictoriaLogs running on an AWS Elastic Kubernetes Service cluster. We do major upgrades to EKS by creating a new cluster, and therefore we have to transfer monitoring data from the old VMSingle instance to the new one. For VictoriaMetrics, there is the vmctl tool which can migrate data through the APIs… Read More »

AI: What is the MCP?

21 May 2025
 

 Everyone around us is talking about MCPs all the time, and it’s time to understand the topic. So, today we will deal with the basic concepts – “what it is in general”, then we will write our own “micro-MCP server”, and in the next post – something more real, about working with VictoriaLogs. LLM Limitations… Read More »

Python: introduction to the Celery, and its monitoring configurations

20 May 2025
 

 To put it very simply, Celery is something we can use to perform tasks outside of our main service. For example, there is a Backend API that has some kind of endpoint to which mobile devices send information that the user has created a new whatever in the application. The task of the Backend is… Read More »