OpenCyber AcademyLesson map
Lesson 01 published. Map, example, EX001.
flowchart TD
N0["Learning outcomes"]
N1["1.1 The case and the computer"]
N2["1.2 How software runs"]
N3["1.3 Hardware and ledger nodes"]
N4["Synthesis"]
N0 --> N1 --> N2 --> N3 --> N4
N4 --> EX["Worked example"]
EX --> Q["Exercise EX001"]
Logical drawing
flowchart LR
N0["Learning outcomes"]
N1["1.1 The case and the computer"]
N2["1.2 How software runs"]
N3["1.3 Hardware and ledger nodes"]
N4["Synthesis"]
N0 --> N1 --> N2 --> N3 --> N4 --> Q["EX001"]
[Learning outcomes]
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[1.1 The case and the computer]
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[1.2 How software runs]
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[1.3 Hardware and ledger nodes]
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[Synthesis]
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[Worked example] --> [Exercise EX001]
Learning outcomes
You will (1) describe the parts of a computer; (2) explain how software runs; (3) relate hardware to ledger nodes.
1.1 The case and the computer
Lucas Moreau is a student technologist at the fictional Pinecrest Technical College, guided by his instructor Ms Grace Adebayo. Over three years he will support the fictional Tidewater Makerspace, about 350 members, which issues equipment-booking credits as tokens on a small permissioned Ethereum-compatible test ledger run on three nodes. Members earn credits by teaching workshops and spend them to book laser cutters and 3D printers. Every person, address and figure in this book is synthetic. Lucas starts with the computer itself, because every ledger node is just software running on ordinary hardware with ordinary limits.
1.2 How software runs
A program is a set of instructions stored on disk. When started, the operating system loads it into memory and the processor executes it, reading and writing data as it goes. A ledger node is a long-running program that listens on the network, processes transactions and blocks, and saves results to disk. Lucas watches a test node start on a lab machine and sees it read its configuration, open its database, connect to peers and begin syncing. Seeing each step helps him understand later error messages, which usually point to one of those stages failing for a specific reason.
1.3 Hardware and ledger nodes
Lucas lists what a node needs: enough processor to validate blocks quickly, enough memory to hold recent state, fast disk for the growing database, a reliable network link and an accurate clock. The makerspace's three nodes run on small servers in a rented rack. He records each server's specification and current usage. Ms Adebayo explains that most node problems technologists meet are resource problems, such as a full disk or an overloaded processor, rather than exotic ledger faults. Knowing the hardware is the first step to keeping nodes healthy and quickly diagnosing them when they are not.
Worked example
Lucas records each server's specification and usage, noting that a node needs processor, memory, fast disk, network and an accurate clock.
Synthetic case. Lucas Moreau, Ms Grace Adebayo, Pinecrest Technical College, Tidewater Makerspace and all data are synthetic.
Errors and limits
Blaming the ledger software for every fault overlooks common resource problems such as a full disk.
Exercises
- EX001 — Makerspace size. How many members does Tidewater Makerspace have?
Show marking criteria
Rubric: 3 = about 350;; 2 = 350;; 1 = 3,500;; 0 = none. - EX002 — Node startup. Name one step Lucas sees during node start.
Show marking criteria
Rubric: 3 = connect to peers;; 2 = open the database;; 1 = print a receipt;; 0 = none. - EX003 — Common fault. What kind of problem do technologists most often meet?
Show marking criteria
Rubric: 3 = resource problems such as a full disk;; 2 = resources;; 1 = exotic ledger faults;; 0 = none.
Synthesis
Ordinary hardware limits explain many ledger node problems.