PDF Info

License: PRO+ (Professional Edition or higher)
Plugin Type: Index Plugin
Author: Diskover Data, Inc.

Overview

The PDF Info plugin extracts metadata from PDF (Portable Document Format) files during the Diskover indexing process. When enabled, this plugin automatically reads document properties such as title, author, subject, creation date, and keywords embedded within PDF files, making this information searchable and reportable in the Diskover web interface.

PDF files often contain valuable metadata that describes a document's origin, purpose, and history. This information is typically invisible when browsing file systems but becomes fully searchable once indexed by this plugin.

Why Use This Plugin?

• Find documents by content properties rather than just filenames

• Track document origins including authors, creation dates, and source applications

• Support compliance and governance with audit trails of document metadata

• Identify document collections created by specific applications or from templates

Use Cases by Role

Legal and Compliance Teams

• Locate contracts and legal documents by author or creation date

• Find all documents created within specific date ranges for discovery requests

Marketing and Creative Teams

• Organize branded document assets by subject and keywords

• Find collateral created by specific team members

Finance and Accounting

• Audit document collections by creation and modification dates

• Find reports authored by specific analysts

IT Administrators

• Analyze PDF document collections across storage

• Generate reports on document metadata for compliance audits

Understanding PDF Metadata

PDF files store metadata in a document information dictionary that contains properties about the file itself. This metadata is separate from the document content and includes:

Some PDFs also contain additional properties like Company (organization name) and Template URL (reference to source template), typically set by Microsoft Office applications.

Note: Not all PDFs contain metadata. Scanned documents, PDFs from certain generators, or files where metadata was intentionally stripped may have empty or minimal metadata fields.

Requirements

Software Requirements

Installation

Step 1: Install Python Dependencies

Install the required pypdf library:

Linux:

python3 -m pip install pypdf==5.1.0

Windows:

python -m pip install pypdf==5.1.0

Verify the installation:

Linux:

python3 -m pip show pypdf

Windows:

python -m pip show pypdf

You should see output showing pypdf version 5.1.0.

Step 2: Configure the Plugin

1. Navigate to Diskover Admin > Plugins > Index Plugins > PDF Info

2. Enable the plugin and configure parameters as needed (see Configuration section)

3. Save the configuration

Step 3: Enable in Index Task Configuration

1. Navigate to Diskover > Configurations > [Your Configuration Name]

2. Scroll to the bottom to find Index Plugins Enablement

3. Enable the PDF Info plugin

4. Save the configuration

The plugin will now run automatically during scans using this configuration.

Configuration

The PDF Info plugin is configured through the Diskover Admin interface.

Configuration Parameters

Configuration Example 1: Default Configuration (Recommended)

The default configuration enables caching with no expiration time:

Linux:

enable_cache: true
cache_dir: /opt/diskover/__pdfinfo_plugin_cache__/
cache_expire_time: 0
index_field_name: pdf_info

Windows:

enable_cache: true
cache_dir: C:\Program Files\Diskover\__pdfinfo_plugin_cache__\
cache_expire_time: 0
index_field_name: pdf_info

This configuration:

• Enables caching to improve performance on subsequent scans

• Uses modification time validation to ensure cached data remains accurate

• Never expires cached entries unless the source file changes

Configuration Example 2: Custom Cache Location

For environments with specific storage requirements:

Linux:

enable_cache: true
cache_dir: /data/diskover_cache/pdfinfo/
cache_expire_time: 604800
index_field_name: pdf_info

Windows:

enable_cache: true
cache_dir: D:\DiskoverCache\pdfinfo\
cache_expire_time: 604800
index_field_name: pdf_info

This configuration:

• Stores cache in a custom directory on a dedicated volume

• Sets cache entries to expire after 7 days (604800 seconds)

• Useful for environments where cache storage must be managed

Important: Ensure the Diskover service user has read/write permissions to the configured cache directory.

Indexed Fields

The PDF Info plugin extracts metadata and stores it in the pdf_info field within each indexed document.

Field Mappings

Example Document

{
  "name": "Q4_Financial_Report.pdf",
  "extension": "pdf",
  "size": 2458624,
  "pdf_info": {
    "title": "Q4 2024 Financial Report",
    "author": "Jane Smith",
    "subject": "Quarterly Financial Summary",
    "creator": "Microsoft Word",
    "producer": "Microsoft: Print To PDF",
    "creation_date": "2024-10-15T14:30:00Z",
    "modification_date": "2024-10-18T09:15:00Z",
    "keywords": "finance, quarterly, confidential",
    "company": "Acme Corporation"
  }
}

Searching in Diskover

Use the following search queries in the Diskover web interface to find PDF documents based on their metadata.

Basic Field Searches

Date-Based Searches

Wildcard Searches

Finding PDFs with Errors or Missing Metadata

Combined Searches

Troubleshooting

Common Issues and Solutions

Cache Management

If you need to clear the cache to force re-extraction of metadata:

Linux:

rm -rf /opt/diskover/__pdfinfo_plugin_cache__/

Windows:

rmdir /s /q "C:\Program Files\Diskover\__pdfinfo_plugin_cache__\"

To create the cache directory with proper permissions:

Linux:

mkdir -p /opt/diskover/__pdfinfo_plugin_cache__
chown diskover:diskover /opt/diskover/__pdfinfo_plugin_cache__
chmod 755 /opt/diskover/__pdfinfo_plugin_cache__

Windows:
Ensure the Diskover service account has read/write permissions to the cache directory.

Debug Logging

To enable verbose logging for troubleshooting, check the Diskover logs:

Linux:

grep -i "pdfinfo" /var/log/diskover/diskover.log | tail -50

Windows:
Check the Diskover service logs or configured log location for entries containing "pdfinfo".

Testing PDF Metadata Extraction

To verify a PDF file contains metadata and can be read by pypdf:

Linux:

python3 -c "from pypdf import PdfReader; r = PdfReader('/path/to/test.pdf'); print(r.metadata)"

Windows:

python -c "from pypdf import PdfReader; r = PdfReader('C:\path\to\test.pdf'); print(r.metadata)"

Support

• Diskover Documentation: https://docs.diskoverdata.com

• Diskover Support: https://support.diskoverdata.com

• pypdf Documentation: https://pypdf.readthedocs.io

Last Updated: January 2026
Diskover Data, Inc.