08 August 2019
Prometheus with Azure Monitor
I have been using Azure AKS for quite some time now and haven't had many problems with it. I run my own observability stack (Prometheus + Grafana) and logging stack (EFK) on AKS myself. I recently noticed on Azures blog that I can ditch my Prometheus from inside kubernetes and have azure take care of scraping and storing the application metrics. If you have been using Prometheus with AKS than there is not much that will change as a developer. If you, however, have been using Prometheus for DevOps related work and are quite good at writing PromQL than embrace yourself for KQL (Kusto Query Language)
<Queries> InsightsMetrics | where Name == "user_management" | extend dimensions=parse_json(Tags) | where request_status == "fail" | where TimeGenerated > todatetime('2019-08-02T09:40:00.000') | where TimeGenerated < todatetime('2019-08-02T09:54:00.000') | project request_status, Num, TimeGenerated | render timechart
12 December 2017
Aerospike vs Redis vs Tarantool
I have been working on a project where we have to store application data (clicks, views, mentions,...etc) in order to do some analytics later on on the data. There are several ways to architect a solution for this kind of problem and although in the past I architected a similar solution to this problem using Apache Kafka and the Citus extension for PostgreSQL this time we decided to use an in-memory storage engine and implement a batch job that regularly aggregates the data and stores it in PostgreSQL.
The question was which in-memory storage engine should we go for? In this post, I will compare three promising tools and do some performance testing on them in order to better evaluate which one to go with. Before I start I have to mention that I am slightly biased towards Redis because I have used it regularly in the past and know my way around it but after having now worked with both Aerospike and Tarantool I have to say that all of them are worthy candidates.
The tests are run on AWS. I use terraform to provision the infrastructure. The picture below shows an overview of the infrastructure. The tools were provisioned as single instances on their own nodes:
YCSB-tester on a c4.2xlarge (This instance was used to run YCSB tool to perform the tests)
Redis-tester(v. 4.0.6) on a m4.xlarge
Tarantool-tester(v. 1.8) on a m4.xlarge
Aerospike-tester(v. 188.8.131.52) on a m4.xlarge
Elasticache-tester(v. 3.2.4) on a cache.m4.xlarge
30 November 2017
In re:Invent 2017 AWS announced AWS Fargate among many other new services. AWS describes Fargate as
A technology that allows you to use containers as a fundamental compute primitive without having to manage the underlying instances
I have experience with ECS and Kubernetes and the underlying machines haven't posed a problem for me to manage. In Kubernetes draining a node for maintenance or update is achieved via the CLI
kubectl drain <node name>
16 September 2017
AWS Network Load Balancer
The other day I received an email from AWS with their latest announcements. I went through the email and saw that AWS now offers a new kind of ELB namely the Network Load Balancer (NLB). Compared to the ALB and the ELB classic the NLB is a layer 4 load balancer (transport). When I clicked the link, the AWS webpage states the following "The Network Load Balancer for the Elastic Load Balancing service is designed to handle millions of requests per second while maintaining ultra-low latencies" and I thought to myself why didn't AWS offer this ELB a year ago when I needed a network load balancer :)
A year ago I worked on a project where the requirements were to capture NetFlow traffic and query CPEs (Customer Premises Equipment) of their status through the SNMP protocol. The SNMP part wasn't that big of a challenge but the NetFlow was more of a challenge. Having 10.000 CPE each with at least 10 interfaces bombing your backend is quite a challenge. One of the requirements was data integrity since the data would be used in a commercial manner. Our initial design consisted of having 5x EC2 instances with NetFlow parsers that would parse and forward (produce) the data to an Apache Kafka cluster. The following picture shows a simplified design
15 January 2017
State of the Cloud
Cloud technologies and services are evolving rapidly and startups are not the only adopters anymore. I can see that many German companies are moving their infrastructure to the cloud, either entirely or partly (hybrid clouds).
In this post I want to take you for a cloud journey! Follow along if you have time.