Merritt

Merritt is the digital preservation repository for the University of California, available to libraries, academic departments, laboratories and other organizational units within UC.

Original System Specifications

• Merritt Object Model
• Technical Specifications
• Digital Object Guidelines

User Documentation

• For the latest Merritt documentation, see the wiki.
• Manifest Validation Tool
• Manifest Validation Tool with Unit Tests
• Merritt Development Resources
• A system-specific dataflow diagram is available via each of the below code repository README files.

Core Microservices Diagram

%%{init: {'theme': 'neutral', 'securityLevel': 'loose', 'themeVariables': {'fontFamily': 'arial'}}}%%
graph TD
  RDS[(Inventory DB)]
  UI("Merritt UI")
  click UI href "https://github.com/CDLUC3/mrt-dashboard" "source code"
  ING(Ingest)
  click ING href "https://github.com/CDLUC3/mrt-ingest" "source code"
  ST(Storage)
  click ST href "https://github.com/CDLUC3/mrt-store" "source code"
  STACC(Storage - Access)
  click STACC href "https://github.com/CDLUC3/mrt-store" "source code"
  INV(Inventory)
  click INV href "https://github.com/CDLUC3/mrt-inventory" "source code"
  CLOUD(("Cloud Storage"))
  click CLOUD href "https://github.com/CDLUC3/mrt-cloud" "source code"
  LDAP[/LDAP\]
  ZFS[/ZFS Working Storage/]
  ZOO>Zookeeper]
  click ZOO href "https://github.com/CDLUC3/mrt-zoo" "source code"
  EZID(EZID Service)
  click EZID href "https://ezid.cdlib.org/" "service link"
  BROWSER[[Browser]]

  subgraph flowchart
    BROWSER --> |ingest or retrieval| UI
    UI --> |authorization| LDAP
    RDS --> UI
    UI --> |"file or ingest manifest"| ING
    ING --> |queue job| ZOO
    ING --> |check obj lock| ZOO
    ZOO --> |start job| ING
    ING -.-> |local id request| INV
    ING --> EZID
    ING --> |download content| ZFS
    ING --> |"sync deposit"| ST
    ST --> CLOUD
    ZFS --> ST
    ZOO --> INV
    INV -.-> |retrieve storage manifest| ST
    INV --> RDS
    UI ---> |retrieval req| STACC
    STACC --> |retrieval req| CLOUD
    CLOUD -.-> |presigned URL| STACC
    STACC -.-> |presigned URL| UI
    CLOUD -.-> |presigned retrieval| BROWSER
  end

  style CLOUD fill:#77913C
  style RDS fill:#F68D2F
  style LDAP fill:cyan
  style ZOO fill:cyan
  style EZID fill:cyan
  
  classDef FOCUS stroke:red,stroke-width:5px,fill:yellow

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Code Repositories

Code Repositories

• Ruby
  • UI
  • Merritt Admin Tool
• Java
  • Ingest
  • Inventory
  • Storage (Store and Access)
  • Replication
  • Audit (Fixity Check)

Libraries

• Java
  • Core
  • Cloud
• Java and Ruby
  • Merritt ZK (created in 2024)
• Ruby
  • SSM Gem - Shared with other UC3 services
  • Merritt Atom - Nuxeo processing for ingest
    • Uses Ruby Ingest

Configuration

• Tomcat

Supporting Services

• Merritt Testing
• Java
  • Merritt Box Tools
• Ruby
  • Merritt End to End Tests
  • Ingest Workspace Manifest Builder
• Docker
  • Merritt Docker
  • Merritt Integration Test Images
• Other
  • Merritt Maintenance Scripts
• Python
  • Merritt Repository Tagger

Merritt DevOps

• Merritt Build System Design
• Merritt Tomcat Deploy
• Merritt Service Release Manifest
• Merritt Sceptre Scripts
• Deprecated?
  • Merritt Ansible Deployment Tools

Project Overview

• Project Board
• System Operations Board
• System Enhancement Ideas Grouped by Theme

More info

• Deprecated Functionality

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Internal Links

• Merritt Troubleshooting