I think I am a big fan of textual UML after I learnt it from thoughtworks techradar. I doubted it after my recent experience. In the past 2 months I spent long periods of time to think of how to make my Powerpoint slides pass my boss Lim Chee Kiam's standard. I thought deeply about that. One moment, I asked myself why Grady Booch, Ivar Jacobson, and James Rumbaugh didn’t come out a diagram which cater to dynamic(behaviour) and static (structure) diagrams, then I realized it will be a mess if those two things are put toghere.

I chose logseq as my PKM I was overloaded with information in the past several weeks. I sought many ways to overcome it. One choice I made is using logseq as PKM. why? There are several open source or freeware verion of PKM. Why did I choose logseq? logseq is clojure based. I am a big fan of lisp-liked languages. I studied and did some coding using racket, common-lisp, elisp and clojure after I read Paul Graham’s essays about lisp.

Installation I installed Ubuntu 22.04 on my laptop following the scripts here. sudo apt-get update sudo apt-get install ca-certificates curl gnupg sudo install -m 0755 -d /etc/apt/keyrings curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg sudo chmod a+r /etc/apt/keyrings/docker.gpg echo \ "deb [arch="$(dpkg --print-architecture)" signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \ "$(. /etc/os-release && echo "$VERSION_CODENAME")" stable" | \ sudo tee /etc/apt/sources.list.d/docker.list > /dev/null sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin service docker start Troubleshootig It is little different from my previous installation.

Item Hash/encryption UUID Order preservation possible (linear hash) possible ( customized UUID algorithm) length shorter or longer fixed ubiquitous anyone or machines can be used to hash depends performance (computing) ? ? performance (search) fast slow References:

Last week I was assigned a task to keep search result pages of a site of my company up to date. After researching, trial and errors, I found out the following ways to keep the search result pages in search engines up to date. Remove outdated content from search result of google and Bing. temporary: block URLs from webmaster tools permanent: get sitemaps.

I never thought I will learn to use powershell seriously. Now I joined NTUC, there are many restrictions. Today I started to use linux utils equivalent in powershell. dig: Resolve-DnsName telnet: Test-NetConnection host: Get-Host touch: New-Item cat: Get-Content tail: Get-Content grep: Where-Object or Select-String man: Get-Help References https://mathieubuisson.github.io/powershell-linux-bash/#pwd- -

2 days ago, I didn’t figure out how to filter out data using power-query. I used a workaround solution to achive the same goal. Yesteray I occasionally found that I can filter out data directly without using my workaround solutions. Table.SelectRows Table.SelectRows( Table.FromRecords({ [CustomerID = 1, Name = "Bob", Phone = "123-4567"], [CustomerID = 2, Name = "Jim", Phone = "987-6543"], [CustomerID = 3, Name = "Paul", Phone = "543-7890"], [CustomerID = 4, Name = "Ringo", Phone = "232-1550"] }), each ( [CustomerID] > 2 and Text.

In my previous two companies, everytime I used the subdomain way without thinking much about this. Recently I wondered the rational behind this decisions. I had the clear answers two days ago. Today I have the time to put it into this writing. Factors subdomain(dev.example.com) subdomain reasons path (example.com/dev/) path reasons server side performance 9 dns records point to differnent IP.

Leader election in Kubernetes control plane - #HeptioProTip give a way how to find out leaders of Kubernetes control plane components kube-scheduler and kube-controller-manager. However it was based on a old version of kubernetes, and the mechanism is changed in later versions. Today I was asked how to find the leaders. Here is the new way to find. $ kubectl -n kube-system get lease NAME HOLDER AGE kube-apiserver-c4vwjftbvpc5os2vvzle4qg27a kube-apiserver-c4vwjftbvpc5os2vvzle4qg27a_b187371d-e48c-4216-8228-707a0ecf6100 2m57s kube-apiserver-dz2dqprdpsgnm756t5rnov7yka kube-apiserver-dz2dqprdpsgnm756t5rnov7yka_0b531f66-0c31-453c-9277-a6c1aa81da94 86s kube-apiserver-fyloo45sdenffw2ugwaz3likua kube-apiserver-fyloo45sdenffw2ugwaz3likua_3e322f9a-9724-4e3a-9fc6-a512e9424164 2m11s kube-controller-manager kind-control-plane_bec39b96-87c4-4bce-8775-2eeb4eb4c1e8 2m53s kube-scheduler kind-control-plane_db6f36d8-ceaa-40eb-b821-75f8ae829f22 2m53s $ kubectl -n kube-system get pods -l component=kube-controller-manager,tier=control-plane \ -o custom-columns=NAME:.

Progressive delivery: Istio Canary Deployments using flagger. Steps environment: kindest/node:v1.25.3 Istio 1.17.0 helm # need to install metrics-server, HPA depends on metrics-server kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml # command: # - /metrics-server # - --kubelet-insecure-tls istioctl manifest install --set profile=default kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.17/samples/addons/prometheus.yaml helm repo add flagger https://flagger.app kubectl apply -f https://raw.githubusercontent.com/fluxcd/flagger/main/artifacts/flagger/crd.yaml helm upgrade -i flagger flagger/flagger \ --namespace=istio-system \ --set crd.