Snapshot Manager

1 min read
Suggest an edit

Overview

Snapshots capture system state at a point in time.

Purpose

Snapshots enable:

  • faster recovery
  • bounded replay time

Snapshot Model

state_snapshot + journal_tail → current_state

Creation

Snapshots are:

  • periodic
  • triggered by runtime policy

Consistency

Snapshots must be:

  • atomic
  • consistent with journal

Recovery

On restart:

  1. load snapshot
  2. replay journal tail

Trade-offs

Frequent snapshots:

  • faster recovery
  • higher overhead

Infrequent snapshots:

  • slower recovery
  • lower overhead