DMS (Document Management System) Services

A comprehensive document management system built with ASP.NET Web Services that integrates with MinIO object storage and SQL Server databases for metadata management.

Overview

The DMS Services system provides a full-featured document management solution with the following key capabilities:

• Document Storage: Binary document storage using MinIO object storage
• Metadata Management: SQL Server database for document metadata, versions, and relationships
• Access Control: Role-based and user-based access control
• Version Control: Document versioning with history tracking
• Categorization: Document categorization and keyword tagging
• Associations: Link documents to external entities (contacts, subscriptions, etc.)
• Web Services API: RESTful web services for document operations
• User Management: Session management and user authentication

Architecture

Technology Stack

• Backend: ASP.NET Web Services (VB.NET)
• Database: SQL Server (metadata storage)
• Object Storage: MinIO (binary document storage)
• Logging: log4net
• Caching: Local caching wrapper
• Authentication: Windows Authentication

System Components

1. Service.asmx - Main web service providing document management operations
2. GetContent.ashx - Content retrieval handler
3. GetContentBE.ashx - Backend content retrieval with advanced filtering
4. OpenDocument.ashx - Document opening and streaming handler
5. Database Schema - SQL Server database with comprehensive metadata tables

Database Schema

The system uses a comprehensive SQL Server database schema with the following main tables:

Core Tables

• Documents - Main document metadata
• Document_Versions - Version control for documents
• Document_Types - File type definitions
• Users - System users
• Groups - User groups for access control

Relationship Tables

• Document_Associations - Links documents to external entities
• Document_Categories - Document categorization
• Document_Keywords - Document tagging
• Document_Users - User access control
• User_Group_Access - Group-based access control

Supporting Tables

• Associations - Association type definitions
• Categories - Category definitions
• Keywords - Keyword definitions
• User_Sessions - Session management

Installation and Setup

Prerequisites

• Windows Server with IIS
• SQL Server 2016 or later
• MinIO server instance
• .NET Framework 4.7.2 or later

Database Setup

1. Run the provided DMS_Database_Schema.sql script to create the database schema
2. Configure connection strings in web.config
3. Set up database users and permissions

MinIO Configuration

1. Install and configure MinIO server
2. Create buckets for document storage
3. Configure access keys and secrets in web.config

Web Application Setup

1. Deploy the web application to IIS
2. Configure application pool with appropriate permissions
3. Update web.config with environment-specific settings
4. Set up logging directories and permissions

Configuration

Web.config Settings

<appSettings>
    <!-- Database Configuration -->
    <add key="dbuser" value="your_db_user" />
    <add key="dbpass" value="your_db_password" />
    
    <!-- MinIO Configuration -->
    <add key="minio-key" value="your_minio_access_key" />
    <add key="minio-secret" value="your_minio_secret_key" />
    <add key="minio-region" value="your_region" />
    <add key="minio-bucket" value="your_bucket_name" />
    
    <!-- System Configuration -->
    <add key="basepath" value="C:\Inetpub\dms\" />
    
    <!-- Debug Settings -->
    <add key="SaveDMSDocDoc_debug" value="N" />
    <add key="GetDocument_debug" value="Y" />
    <!-- ... other debug settings ... -->
</appSettings>

<connectionStrings>
    <add name="dms" connectionString="server=your_server;database=DMS;Min Pool Size=3;Max Pool Size=5;Connect Timeout=10" providerName="System.Data.SqlClient" />
    <add name="siebeldb" connectionString="server=your_server;database=siebeldb;Min Pool Size=3;Max Pool Size=5" providerName="System.Data.SqlClient" />
    <add name="hcidb" connectionString="server=your_server;Min Pool Size=3;Max Pool Size=5;Connect Timeout=10;database=your_database" providerName="System.Data.SqlClient" />
</connectionStrings>

API Reference

Main Web Service Methods

Document Management

• SaveDMSDoc - Save or update a document
• UpdateDoc - Update an existing document
• GetDocument - Retrieve document information
• DelDocument - Delete a document
• PublishDMSDoc - Publish document to users

Document Associations

• SaveDMSDocAssoc - Create document associations
• SaveDMSDocCat - Assign document categories
• SaveDMSDocKey - Assign document keywords
• SaveDMSDocUser - Set document user access

User Management

• UserLogin - User authentication
• UserLogout - User session termination
• CheckDocAccess - Verify document access rights

Utility Functions

• VerifyDocument - Document verification
• UpdDMSDocCount - Update document counts
• EmpQuery - Employee query operations

Handler Endpoints

• GetContent.ashx - Content retrieval with filtering
• GetContentBE.ashx - Advanced content retrieval
• OpenDocument.ashx - Document streaming and opening

Usage Examples

Saving a Document

Dim service As New Service()
Dim result As String = service.SaveDMSDoc(
    DocId:="", 
    ItemName:="Sample Document", 
    DFileName:="sample.pdf",
    DImage:="base64_encoded_content",
    DSize:="1024",
    UserId:="user123",
    Debug:="N"
)

Retrieving Documents

Dim service As New Service()
Dim result As String = service.GetDocument(
    DocId:="123",
    UserId:="user123",
    Debug:="N"
)

Creating Document Associations

Dim service As New Service()
Dim result As String = service.SaveDMSDocAssoc(
    DocId:="123",
    Association:="Contact",
    AssocKey:="contact456",
    PrFlag:="Y",
    ReqdFlag:="N",
    Rights:="READ",
    Debug:="N"
)

Security Features

Access Control

• User-based Access: Individual user permissions for documents
• Group-based Access: Role-based access control through groups
• Document-level Security: Per-document access control
• Session Management: Secure session handling with expiration

Data Protection

• Binary Storage: Documents stored securely in MinIO
• Metadata Encryption: Sensitive metadata protection
• Audit Logging: Comprehensive logging of all operations
• Input Validation: SQL injection and XSS protection

Logging and Monitoring

Logging Configuration

The system uses log4net for comprehensive logging:

• Event Logging: System events and errors
• Debug Logging: Detailed operation tracing
• Performance Logging: Operation timing and metrics
• File-based Logging: Rotating log files with size limits

Log Categories

• EventLog: System events and errors
• PDDDebugLog: Document operations debugging
• AUDDCDebugLog: Audit operations
• UDDCDebugLog: User operations
• SDDADebugLog: System operations

Performance Considerations

Caching

• Local Caching: In-memory caching for frequently accessed data
• Database Connection Pooling: Optimized connection management
• Query Optimization: Indexed database queries

Scalability

• MinIO Integration: Scalable object storage
• Database Optimization: Proper indexing and query optimization
• Load Balancing: Support for multiple application instances

Troubleshooting

Common Issues

1. Database Connection Errors

   • Verify connection strings in web.config
   • Check database server availability
   • Validate user permissions

2. MinIO Connection Issues

   • Verify MinIO server configuration
   • Check access keys and secrets
   • Validate network connectivity

3. Document Upload Failures

   • Check file size limits
   • Verify MinIO bucket permissions
   • Review error logs for specific issues

Debug Mode

Enable debug mode by setting debug flags to "Y" in web.config:

<add key="SaveDMSDocDoc_debug" value="Y" />
<add key="GetDocument_debug" value="Y" />

Development and Customization

Adding New Document Types

1. Insert new record in Document_Types table
2. Update MIME type handling in OpenDocument.ashx
3. Test document upload and retrieval

Custom Associations

1. Add new association type to Associations table
2. Update association handling in service methods
3. Modify UI components as needed

Extending Access Control

1. Add new user groups to Groups table
2. Update access control logic in service methods
3. Modify permission checking functions

File Structure

DMS_Services/
├── App_Code/
│   └── Service.vb                 # Main service implementation
├── Bin/                          # Compiled assemblies
├── images/                       # UI images and icons
├── js/                          # JavaScript files
├── packages/                    # NuGet packages
├── work_dir/                    # Temporary working directory
├── Service.asmx                 # Web service definition
├── GetContent.ashx              # Content retrieval handler
├── GetContentBE.ashx            # Backend content handler
├── OpenDocument.ashx            # Document opening handler
├── web.config                   # Application configuration
├── packages.config              # Package dependencies
└── README.md                    # This documentation

Dependencies

NuGet Packages

• AWSSDK.S3 (3.7.1.3) - MinIO/S3 integration
• AWSSDK.Core (3.7.0.33) - AWS SDK core
• log4net (2.0.12) - Logging framework
• Newtonsoft.Json (13.0.1) - JSON serialization
• RestSharp (106.11.7) - HTTP client
• System.Reactive (5.0.0) - Reactive extensions

System Requirements

• .NET Framework: 4.7.2 or later
• IIS: 8.0 or later
• SQL Server: 2016 or later
• Windows Server: 2012 R2 or later

License and Support

This document management system is designed for enterprise use with comprehensive security and scalability features. For support and customization requests, please contact the development team.

Version History

• v1.0 - Initial release with core document management features
• v1.1 - Added MinIO integration and enhanced security
• v1.2 - Improved performance and caching
• v1.3 - Enhanced user management and access control

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Last Updated: [Current Date] Version: 1.3