Continuing with the Kubernetes: monitoring with Prometheus – exporters, a Service Discovery, and its roles, where we configured Prometheus manually to see how it’s working – now, let’s try to use Prometheus Operator installed via Helm chart. So, the task is spin up a Prometheus server and all necessary exporter in an AWS Elastic Kubernetes… Read More »
Kubernetes HorizontalPodAutoscaler automatically scales Kubernetes Pods under ReplicationController, Deployment, or ReplicaSet controllers basing on its CPU, memory, or other metrics. It was shortly discussed in the Kubernetes: running metrics-server in AWS EKS for a Kubernetes Pod AutoScaler post, now let’s go deeper to check all options available for scaling. For HPA you can use three… Read More »
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 »
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 »