Delegation

April 9th, 2023

Delegation is a good design choice only when it simplifies more than it complicates. (Gamma et al. 21)

Work Cited: Gamma, Erich, et al. Design Patterns: Elements of Reusable Object-Oriented Software. Addison-Wesley, 1994.

京セラ経営哲学

April 2nd, 2023
Posted in 日本語 | No Comments
「人間にんげんとして正ただしいことは何なんなのか」ということを
基準きじゅんに判断はんだんを行おこなわなくてはならない。
We must make decisions based on what is right as human beings.

My Pandemic 2020 Build

April 8th, 2022

Parts List:

  • AMD Ryzen 5 3600X w/Wraith Spire Cooler [$189.99]
  • MSI MPG X570 Gaming Plus ATX [$154.99]
  • MSI Radeon RX5700 XT Gaming X 8GB 256-bit GDDR6 PCI Express 4.0 [$409.99]
  • G.SKILL Ripjaws V DDR4-3200 CL16-18-18-38 1.35V 128GB (4x32GB) 288-pin [$429.98]
  • Samsung 970 EVO Plus NVMe M.2 SSD 2000GB [$249.99]
  • Samsung 970 EVO Plus NVMe M.2 SSD 500GB [$104.99]
  • NZXT H510i ATX Case [$99.99]
  • Corsair RM850 80+G Fully Modular ATX PSU [$159.99]
  • Microsoft Windows 10 Pro (Retail) [$199.99]

128 GB of RAM is overkill. A G.SKILL 32GB (4x8GB) F4-3200C16Q-32GVK kit would have saved $190.98. Not purchasing a 500GB SSD would have saved $104.99.

On idle: CPU temp 38℃, System temp 31℃, CPU fan @ 1325RPM. Case fans @ 950RPM. Case noise (as reported by NZXTcam): 48db.

treehash.py – Amazon S3 Glacier Tree Hash

February 20th, 2022

I am planning to implement a bare-bones system to backup pictures, videos, financial records, and software development projects. Among Google, Microsoft, and Amazon, I find that the long term storage services offered by Amazon to be cost effective at $0.0036 per GB per month or $3.60/mo for 1TB. Amazon S3 Glacier also provides a mechanism for fetching an inventory of files uploaded to their service. This inventory includes a tree hash or checksum for each “archive” that is uploaded. (At $0.00099 per GB per month or $0.99/mo for 1 TB, an even more cost effective alternative is using the S3 Glacier Deep Archive storage class for data stored in Amazon S3 buckets. Amazon S3 Glacier is different from Amazon S3 with the S3 Glacier Deep Archive storage class in that the former deals with vaults and archives whereas the latter deals with buckets and storage classes. Unfortunately, the Amazon S3 service does not provide a reliable mechanism for retrieving checksum data.)

Amazon claims their S3 services achieve 99.999999999% (“eleven nines”) durability. I am uncertain that I can achieve the same level of durability independently. As part of my backup system, I need to periodically check for differences between my local files and my backups. To confirm that local copies of archives uploaded to Amazon Web Services are identical, I implemented a standalone Python script that generates the Amazon S3 Glacier tree hash checksum: treehash.py.

The script can be used with a command line interface as follows:
python3 treehash.py inputfile.bin

Happy New Year 2022!

January 15th, 2022

For the new year, I resolve to focus on the following:

  • health: lose 25 pounds in 20 weeks using diet and exercise, and 45 pounds by the end of the year
  • finance: generate returns by periodically establishing high probability of profit options trades
  • career: focus on developing marketable skills, specifically skills in securing software architectures implemented with microservices
  • hobbies: Japanese language learning by reaching level 40 on WaniKani by June

2021 felt like a continuation of 2020. Here’s to hoping that 2022 is not like 2020 too!