YAPC::EU 2012 第二天

作者：gugod 發佈於：2012/09/01

第二天的主講人是 Curtis "Ovid" Poe，所分享的是他的新版 Agile Manifesto。強調 Agile 是種思維，而非刻板的工作程序。似乎與我這則玩笑互相回應：

Scrum 並不是種嚴謹的方法論。但其之所以管用，是因為全團隊上下在實踐之時，都要了解這個方法及其意義。比較像是群體自我意識提升。那麼，整公司一起去練法輪功，可能也有類似的效果。
— Kang-min Liuさん (@gugod) 7月 22, 2012

由於第一天也有人提到 Continuous Deployment，於是也趁機點出了「測試、監控、記錄」這三種工具的重要性。有寫測試，能在出新版之前先行找出瑕疪；有做監控，就能在即時發現錯誤．有做記錄，則可在錯誤發生之後，全面了解狀況。

但私以為，全篇演講最重要的一句話，是在開頭的這一句：

I realized I've been teaching people how to rewrie agile manifesto

講者多年來自省推行 Agile 的過程而發現，其實自己是在教大眾這個概念的精神為何，而非死背原創。如此具備彈性，顯然也是 Agile 精神的一種實踐。

接著是 Parrot 的 Thread 支援，在這一年之中被實做出來了。所實做的是基於 Green thread 的 Worker thread。重點摘要如下：

是 interpretor thread 的變種，能支援多核心
每支 Thread 自有 Garbage Collector
Thread 的執行內容為一 "Task" 物件，有新工作項目時，則丟進 Scheduler 排班執行
變數只有其所屬的 thread 可以寫入，其他 thread 只能透過 Proxy 物件讀取共享變數內容
Proxy 物件存在於 intrepretor main thread，能存取所有記憶體空間。

講者 nine 有提到基本上 Proxy 物件與多份 GC 的設計是相關的，不過細節就沒有說明了。猜想是類似 objc 的 autorelease pool 這類的，不特別做 ref count 與 mark and swipe，而是在 thread 結束時一次全部清掉的做法。這部份要再確認。

顯然 ElasticSearch 在 EU Perl 社群中也十分火紅，在 YAPC::EU 中也有好幾堂課跟 ElasticSearch 有關。Lucy 倒是一個字眼都沒看到了。其易用性顯然對開發人員來說也是十分重要的。

今天許多講題內容都與 agile 的工具與精神相關， Message::Passing 似乎是值得一玩的工具。

晚上有公司贊助的 "Beer & Engineering" ，不過我沒有酒量，就只喝可樂了(笑)。

這一天的筆記如下：

yapc eu 2012 day 2
- keynote
  - people who are writing tests are trying to excel.
  - 10% of the companies are in the top 10% :)
  - Sharpshooter PrRoblem -- shoot 1st. announce your target.
  - "I realized I've been teaching people how to rewrie agile manifesto"
  - Goal / Strategy / Tatics
  - Structured Interviews
    - desigen a set of question and ask all the candidates the same set of question
  - Agile = Mindset. != Process
  - Agile org:
    - Everyone is an owner, which means "responsibility", that leads to the requirement authority.
    - Authority requires information.
    - Ownership implies Trust.
  - Agile Workflow perspective = Compomise
    - tasks!, !processes.
  - Courage instead of fear. (rollout = courage?)
    - minimize risk / maximize reward.
  - Test + Monitoring + Logging = Trinity of being Agile.
    - Test: know what's happening before release
    - Monitoring: know what's happening during release
    - Logging: know what's happening after release.
- parrot thread
  - green threads
    - Interpretor threads
    - "Tasks" + Run Loop. Sounds very similary to async/event-driven paradigm.
  - hybrid thread
    - Worker threads.
      - has 'Task' queue.
    - explicit sharing.
      - variable is owned by exactly one thread.
        read only to other threads.
- Message::Passing use case
  - multi-output possible.
  - with Dancer GUI to do log search
- array programming
  - paradigm
  - Array::APX / Array::Deeputils
  - tons of vector-based operations.
  - prime number selection
    - Any number that's NOT in the matrix of [2..] x [2..]
- joy of breaking things
  - exploits ~ combinations of features
- social network analysis
  - SNA::Network::*
- mst
  - insufficiently automated infrastructure.
  - mongodb complaint?
  - picked up sudo for a while..
  - Object::Remote can bridge code further
  - Data is aggregated with git and JSON files in git repo.
  - sudo vs shared ssh root key?
    - sudo make is easier to lock the sudoer.
    - shared password is always the worst. :)