DSM 0.1.2 · English Edition

Head First DSM

From Shared State to Verifiable Consistency Boundaries

26 chapters · 6 learning arcs · 1 order-fulfillment control plane

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LEARNING PATH

Six advances from calling APIs to proving boundaries

ARC 1 · Chapters 1–4See Shared StateSeparate business facts, coordination state, and event history. ARC 2 · Chapters 5–9Choose Consistency SemanticsSelect Register, Lease, or CRDT from an invariant. ARC 3 · Chapters 10–14Understand Replication and RepairObserve propagation, repair, and response boundaries. ARC 4 · Chapters 15–18Integrate Application EngineeringContain DSM in domain ports, assembly, and test boundaries. ARC 5 · Chapters 19–22Own Runtime OperationsDefine diagnostics, security, lifecycle, and capacity contracts. ARC 6 · Chapters 23–26Prove Boundaries and DeliverComplete the work through real ports, exclusion, and evidence.

Head First DSM — English Contents

This book serves Java developers who share coordination state across service instances. DSM centralizes state identity, typed collections, online propagation, conflict handling, and replica repair in one Runtime, reducing repeated infrastructure work in individual services. An order-fulfillment control plane runs through the book. The sequence—identify state, choose semantics, understand replication, integrate an application, own operations, and validate boundaries—turns DSM's value into executable experiments and reviewable decisions. Appendices support lookup and do not replace the learning path.

After all six arcs, a developer can identify repairable coordination state, choose Register, Lease, or CRDT, integrate through a domain adapter, and state proven and open scope from multi-node, fault, and real-port evidence. Orders, inventory, payments, and complete event history remain with their transactional or log-based systems of record.

Reading surfaces

Value-realization path

Learning stage Engineering capability Repeated work reduced Business/target environment retains
Arc 1: identify and start divide state responsibility; create Runtime, identity, and two-node visibility registration, encoding, basic propagation entry suitability and timing of remote dependence
Arc 2: choose semantics choose Register, Lease, or CRDT from an invariant conflict resolution, lease management, state merge authoritative facts, fencing, partition consequences
Arc 3: replicate and repair observe membership, delta, repair, backpressure, and local success online propagation, gap detection, replica catch-up external effects, durable history, response semantics
Arc 4: integrate applications use domain ports, Spring Boot, isolation, and layered tests centralized assembly, failure translation, layered validation domain contract and production acceptance
Arc 5: own operations define diagnostics, security, lifecycle, and capacity contracts shared observation, security gates, hot-path benchmarks thresholds, key custody, drain, production capacity
Arc 6: validate boundaries decide from real ports, federation, exclusion, and capstone reusable experiments and evidence chain final adoption and deployment approval

Source and evidence convention: DSM APIs, implementations, tests, and official examples link to reviewed GitHub revisions so default-branch changes cannot silently alter the evidence. Commands use submodule/dsm and submodule/dsm-examples as checkout paths. Book-owned exercise assets use repository-relative paths.

Before starting

Arc 1: See Shared State

Chapter Topic
1 DSM Responsibilities and Applicability
2 Start the First Runtime
3 Stable Identity for Shared State
4 From Local Commit to Remote Visibility

Arc 1 recap

Arc 2: Choose the Right Consistency Semantics

Chapter Topic
5 Register: Current Values and Stale Reads
6 Concurrent Register Writes and Deterministic Convergence
7 Lease: Time-Bounded Ownership
8 CRDT: Multi-Node Local Updates and Merge
9 Choose Collections from Business Invariants

Arc 2 recap

Arc 3: Understand Replication, Partition, and Repair

Chapter Topic
10 Member Views and Stability
11 The Remote Path of One Write
12 Digest-Based Difference Detection and Replica Repair
13 ChangeStream Backpressure and Overflow
14 Convergence Boundaries and Responses Already Returned

Arc 3 recap

Arc 4: Integrate Real Application Engineering

Chapter Topic
15 Isolate DSM Details with a Domain Adapter
16 Assemble Runtime with Spring Boot
17 Isolate Communication and Collection Domains
18 Scope of Layered Test Evidence

Arc 4 recap

Arc 5: Make the System Operable

Chapter Topic
19 Locate Replica Differences with Observable Signals
20 Message Security and Convergence Preconditions
21 Runtime Lifecycle and Traffic Admission
22 From Microbenchmark to Production Capacity Evidence

Arc 5 recap

Arc 6: Prove Boundaries and Complete the Capstone

Chapter Topic
23 Observe Consistency Boundaries through Real Ports
24 Collection Semantics across Clusters
25 Identify State That Does Not Fit DSM
26 Deliver a Reviewable Fulfillment Control Plane

Arc 6 recap

Appendices

The complete target map is in the editorial control plane.