Author: valerauko

Két nap szünet a táborban

Amíg feltelepültünk a 3000m-es táborba, jó időnk volt. Kérdéses, hogy a gleccseren tűző nap és meleg tényleg jó időnek számít-e, de a következő két nap hóviharainál csak jobb volt. Ideje hát szót ejteni egy kicsit a tábori életről is a Denalin.


The snowshoe days

Arriving on the Kahiltna glacier we quickly set up camp and just passed out before a late night (or early morning?) start. Lower on the mountain we’d start moving in the middle of the night, so we avoid getting roasted, boiled and blinded by the sun on the snow. Then again even at 3am it was bright enough that I could count on one hand the occasions I had to use my headlamp during the three weeks total.


Reaching Denali

To climb Denali, you first need to get there. So my mission was to reach Anchorage from Tokyo in the middle of June (with all the fun of covid restrictions included). It went surprisingly smoothly. There were a few scary moments, like when people told me Hungarians wouldn’t be allowed entry to the US because of covid—but the restriction turned out not to be about EU nationalities but traveling from EU area.


Azok a fránya tervek

Az év elején írtam róla, hogy a koronavírus hogy megtépázta a terveimet. Akkor úgy volt, hogy tavasszal az Island peak (6189m), majd nyáron a Broad Peak (8047m) és a K2 (8611m) lesz úticél. Végül persze a korona jobban tudta, és sikerült mindkét tervemet bedöntenie.

Havas erdő Naganoban

Upgrading my cluster

My cluster is now running on k3s 1.20.6 and Argo CD 2.0.0 with its Helm chart at 3.2.2. Actually, upgrading Argo itself wasn’t much of a problem. I just changed the targetRevision of the Application and it was up and running in a few minutes. Then a few days later things got interesting.

There were no downtimes, but I noticed that Argo started failing to sync itself. Apparently a new minor version of the Helm chart came out (though it was still the same application version) that added support for the networking.k8s.io/v1 version of Ingress. However, it also accidentally broke clusters running Kubernetes before 1.19. And mine was one such.

While the Argo people are figuring out how to fix this (if), I decided to go and take this opportunity to upgrade my cluster. This wasn’t as painless as it should’ve been though.


Gear I want and gear I can’t seem to find

The mountain gear I look for the most is: very light but durable protection for my limbs. That means gloves and boots that are as light and breathable, quick-drying as possible so my hands and feet don’t rot in sweat in the summer heat, while being durable enough not to fall apart scrambling over rocks in the Japanese alps.

Rocky route in the Japanese alps (at Nishi-Hotaka)

Dealing with DiskPressure

My 4-node k3s cluster (where this blog is hosted too) kept dying every now and then. Looking at kubectl describe nodes it quickly became evident that this was caused by the nodes running out of disk space. Once a node gets tainted with HasDiskPressure, pods might get evicted and the kubelet will be using (quite a lot of) CPU trying to free disk space by garbage collecting container images and freeing ephemeral storage.

My setup by default uses local storage (the local-path provider) where volumes are actually local folders on the node. This means that pods that use persistence are stuck with the same node forever and can’t just move around. This makes eviction a problem, since they have nowhere else to go. It also means that disk usage is actually disk usage on the node, and not on some block volume over the network.


Változnak a tervek

A koronavírus az én terveimet se kíméli. Tavaly nyáron Indonéziába terveztem menni, megmászni Óceánia legmagasabb hegyét, majd ősszel egy duplát terveztem a Himalájába, ahol egy egy hónapos túra során másztam volna meg a Mera Peaket és az Island Peaket. Először a nyári út úszott el, ami helyett még próbáltam másik vezetővel megszervezni ugyanazt, de persze a vírus jobban tudta.

K2 from the north
Photo by Kuno Lechner

Így arra már számítottam, hogy ősszel én már nem megyek majd a Himalájába, de hogy még a ritkaságszámba menő családi lagzira se jutottam el, az egy kicsit fájt. Az őszi duplát végül sikerült átszerveznem 2021 tavaszra, de erről is a minap szóltak, hogy nem lesz megtartva, mert nem jött össze a szükséges létszám.

Mi lesz így akkor idén?


The! Sauna! (and then some snow)

I decided to spend a weekend relaxing. In my sense this means going to the countryside, maybe doing a few hours of something and then just being lazy for the rest. That was exactly the plan. I went with the vague idea that maybe I’d climb Mt Myoko, but though I had the gear for it, it did not happen. What instead happened was, in a short summary, a really nice long weekend.

Lake Nojiri

Clojerlを使ってみる

ErlangはEricssonがはるか昔に開発した通信環境用の言語で、ものすごく頑丈で安定している環境として有名。実際に世界中のモバイル通信環境で用いられ99.9999999% (“nine nines”) の可用性を誇っている。最近ではRuby風でErlangのBEAMを実行環境とするElixirが流行っている印象がある。分散を前提にしている関数型言語としてClojureに近いと感じた。そして実際にBEAMの上でClojureを実装しているものがある。

Clojureが最初はJVMと.NETのCLRも対象にしていたが後JVMだけになり、またClojureScriptの登場でJavaScript上で動くようになった。だから根本的なところは案外実行環境に依存しないところもあるかもしれない。BEAM上でClojureを実装しているClojerlはあくまでもコミュニティーからのもので正式なClojure版ではないが、試したかったBEAMと選べるなら選ぶぐらい好きなClojureが合ったものに当たるから触ってみざるをえなかった。