I ran it by cursor to get a quick understanding of whether it was viable and valuable to switch despite almost perfecting my current HTML → PDF solution.
For my particular application there is a strong risk of many concurrent users as the core feature of the site is the create of the PDF’s
HTML to PDF (Current with Lucee):
Memory Usage:
Lightweight - uses Lucee’s built-in PDF engine
Each conversion ~10-20MB RAM
Memory released efficiently after conversion
Predictable memory footprint
Concurrency:
Native to Lucee’s PDF engine
Efficient request handling
No external process overhead
Clean resource management
Speed:
Fast conversion time
No startup delay
Immediate processing
Direct output
Reliability:
Integrated with Lucee
Minimal failure points
Self-contained
Predictable behavior
With 64GB RAM and 4-core CPU, estimated concurrent users:
~2000-3000 concurrent conversions possible
Memory usage: 20MB × 2000 = 40GB
CPU becomes main bottleneck
Very efficient memory cleanup
LibreOffice Approach:
Memory Usage:
~200MB per LibreOffice instance
Requires queue management overhead
Longer memory retention
Higher per-conversion footprint
Concurrency:
Needs queue system
Process creation overhead
Complex cleanup required
Resource intensive
Speed:
Slower (LibreOffice startup)
Queue waiting times
Heavy disk operations
Process initialization cost
Reliability:
External LibreOffice dependency
Multiple failure points
Complex process management
OS resource dependencies
With 64GB RAM and 4-core CPU, estimated concurrent users:
~30-40 concurrent conversions maximum
Memory usage: 200MB × 30 = 6GB
CPU heavily impacted by LibreOffice processes
Limited by process management overhead
Summary for 4-core CPU, 64GB RAM scenario:
HTML to PDF (Lucee):
Better choice
Could handle 2000+ concurrent users
Memory efficient
CPU efficient
LibreOffice:
More resource intensive
Limited to 30-40 concurrent users
Higher system impact
Process management overhead
Recommendation:
Stick with Lucee’s HTML to PDF - it will handle significantly more concurrent users with the same hardware and is much more efficient in both memory and CPU usage.