Systems Performance: Enterprise and the Cloud を読む

Systems Performance: Enterprise and the Cloudを読んでいます。システム管理の分野で顕著な成果として2013年度のLISA Awardというのを受賞した書籍らしいのですが、これがまた面白い。たぶん自分が何を説明しているのかを正確に理解している人が、わかりやすく伝える努力を惜しまずに書くとこんな書籍になるのだと思う。これは最後まで読まねば。




  • 2014/10/31: Introductionの途中までメモ
  • 2014/11/01: Methodologyの途中までメモ


There are known knowns; there are thing we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns — there are things we do not know we do not know.

— U.S. Secretary of Defense Donald Rumsfeld, Feb 12, 2002

この書籍で扱う Performance は、”unknown unknowns”、「つまり知らないことすら認識していないこと」だと述べていく。この出だしだけで、この書籍が巧みに読者の興味をくすぐっている事がわかるかと思う。






It is capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.

— Sherlock Holmes in “A Scandal in Bohemia” by Sir Arthur Conan Doyle


Input/Output operations per second is a measure of the rate of data transfer operation.

The rate of work performed. Especially in communications, the term is used to refer to the data rate (byte per second or bit per second).

The time for an operation to complete. This includes any time spent waiting and time spent being serviced (service time), including the time to transfer the result.

A measure of time an operation spends waiting to be serviced.

For resources that service requests, utilization is a measure of how busy a resource is, based on how much time in a given interval it was actively performing work.

The degree to which a resource has queued work it cannot service.

In system performance, a bottleneck is a resource that limits the performance of the system. Identifying and removing systematic bottlenecks is a key activity of system performance.

The input to the system or the load applied is the workload.