Is GreptimeDB suitable as a long-term storage solution for Prometheus? To find an answer to this question, I set up a simple configuration of GreptimeDB (v0.13) to investigate.

What is GreptimeDB?

GreptimeDB is an open-source cloud-native time series database that integrates metrics, logs, and events.

Each solution is the root of the next problem – Gerald M. Weinberg

I’ve been using Jsonnet for several years, and I think it would be good to summarize my experiences so far.

The good

The best thing about Jsonnet is that it’s a superset of JSON. As a data templating language for generating JSON, it provides many features of programming languages (variables, functions, arithmetic operations, conditionals). Since it can generate JSON, it can also generate YAML, which is why I use it with tanka to create Kubernetes manifests.

Cortex

Cortex, started by Tom Wilkie and Julius Volz (Prometheus’ co-founder) in 2016, has several interesting architectural features. As one of Prometheus’ long-term storage solutions, Cortex has been referenced by many time-series based storage architectures (tracing, log) since then (especially in the Grafana stack).

Kubernetes upgrades (especially EKS) are categorized into two types based on the Kubernetes architecture:

• Control plane upgrade (+ etcd)
• Node upgrade

Particularly when using cloud-managed Kubernetes like EKS, since AWS manages the control plane, you’ll mostly handle node upgrades directly (if you’re not using managed nodegroups).

Prometheus 101

I created a simple presentation about Prometheus. I uploaded it using sporto/hugo-remark: A theme for using remark.js with hugo, and I found that creating it in markdown rather than PowerPoint allowed me to focus more on the content. (But that doesn’t necessarily mean the content is better.)

For golang based HTTP/REST API documentation,I choose swagger. go-swagger has several features for swagger documentation. The go-swagger can generate swagger spec based code generation but I already have an REST API server. I use go-swagger with golang comment annotation for swagger spec generation.

For REST API development, Design first with writing spec and then generating codes from it is a good approach. goa is a famous tool for this style.

One of pleasures about coding is using good tools. Recently I use bumpversion, govvv and drone for version releasing.

bumpversion

bumpversion is automation for semantic versioning. Most of my projects have simple config file like below. (.bumpversion.cfg)

[bumpversion]
commit = True
tag = True
current_version = 0.8.4
parse = (?P<major>\d+)\.(?P<minor>\d+)\.(?P<patch>\d+)
serialize = 
	{major}.{minor}.{patch}
[bumpversion:file:VERSION]

Before release,I just run like below:

The Docker machine is a command tool created by the docker team to manage docker servers. It automatically creates hosts and installs docker engine on them and configures the docker client to talk.

If you install the docker machine tool,you can use it like below:

오랜만에 docker-korea meetup에서 About Docker Swarm이라는 이름으로 작은 발표를 했다.

장표는 매우 간단하게 구성하고 데모에서 많은 이야기를 하고 싶었는데. 프로젝터설정부터 힘들어서 준비했던것을 절반밖에 이야기하지 못한것 같다.

Docker Swarm은 다른 클러스텅 시스템과 다른 부분들이 있다. 가장 큰 다른 점은 Docker에서 만들었다는 것. 즉 coreos/fleet이 Distributed Init System을 표방하는 것과 비슷하게 Swarm은 Docker-native Clustering System을 이야기한다. ¹