In the previous post – Neo4j: graph database – run with Docker and Cypher QL examples – we’ve run the Neo4j database with в Docker. The next task is to run it in the Kubernetes cluster. Will use the Neo4j Community Edition, which will be running as a single-node instance as cluster ability for the… Read More »
For the persistent data Kubernetes provides two main types of objects – the PersistentVolume and PersistentVolumeClaim. PersistentVolume – is a storage device and a filesystem volume on it, for example, it could be AWS EBS, which is attached to an AWS EC2, and from the cluster’s perspective of view, a PersistentVolume is a similar resource… Read More »
In contrast to the RDMS (Relational Database Management System), where data objects are the main part, in a Graph Database, the relations between such data objects are playing the main role and are represented as dedicated objects which gives better performance especially when you have a lot of small data pieces tied to each other.… Read More »
We have a Kubernetes Cron Job which failed on its last run. Let’s look for the root cause and then will see how to restart such a failed job. List current jobs: [simterm] $ kk -n eks-prod-1-bttrm-apps-ns get cronjobs NAME SCHEDULE SUSPEND ACTIVE LAST SCHEDULE AGE bttrm-apps-backend-reccuring-payment-cron 0 10 * * * False 1 22m… Read More »
Currently, to collect metrics from the AWS CloudWatch we are using AWS’s own cloudwatch-exporter, see the Prometheus: CloudWatch exporter — сбор метрик из AWS и графики в Grafana post (in Rus), but it has a few gaps: it’s written in Java, so uses CPU/memory of the monitoring host doesn’t scrapes AWS tags from resources uses… Read More »
A really nice Android phone and a Linux OS integration. Besides the KDE Connect, you can use gnome-shell-extension-gsconnect if you’d prefer the Gnome project. In this post, we will set up KDE COnnect between an Android HTC phone and Arch Linux. On Android install the KDE Connect from the Play Market. On Linux, install from… Read More »
For network communications, Kubernetes presents four Service types – ClusterIP (the default one), NodePort, LoadBalancer, and ExternalName, plus the Ingress resources. In this post, we will take a short overview of all of them, and will check how they are working. The documentation is available here – Publishing Services (ServiceTypes). I’m using AWS Elastic Kubernetes… Read More »
We have a Redis service running behind a Service with the ClusterIP type. This Redis must accessible by pods from the same namespace (a Gorush service). The problem is that those pod can’t connect to the Redis service using its gorush-server-redis-svc:6379 name and reporting “Can’t connect redis server: connection refused“: [simterm] $ kk -n gorush-test… Read More »
I have a CloudFormation stack with VPC Peerings, in that case, it’s a peering between VPC of a new Elastic Kubernetes Service cluster and VPC of the Prometheus monitoring stack. The EKS cluster’s stack and its whole automation creation were described in the AWS Elastic Kubernetes Service: a cluster creation automation, part 1 – CloudFormation… Read More »
During a Docker image build – it stops asking to configure the tzdata. Dockerfile at this moment is the next: FROM ubuntu:18.04 RUN apt update && apt install -y python-pip python-dev ssh python-boto3 RUN pip install ansible==2.4.3.0 Let’s reproduce – run the build: [simterm] admin@jenkins-production:~$ docker build -t proj/proj-ansible:1.1 . Sending build context to Docker… Read More »