Performance issue on 4CPU systems

There is a known performanse issue in Tesseract 4/5 on 4CPU systems:

https://github.com/tesseract-ocr/tesseract/issues/263#issuecomment-1008431653

You should add enviroment variable OMP_THREAD_LIMIT=1 to the OCR container:

docker-compose.yml

	 ocr:
	image: "ci.rpaplatform.org:8080/rpaplatform/easy-rpa-ocr:3.1.0"
	. . . . . . 
	environment:
	 . . . . . .	
	- "OMP_THREAD_LIMIT=1"
	volumes:
	 . . . . . .

Adding additional languge libriaries

Platforms OCR container contains only the following languages installed after platform installation:

tesseract-ocr-eng
tesseract-ocr-rus
tesseract-ocr-ukr
tesseract-ocr-fra
tesseract-ocr-deu

Here are the language codes:

https://tesseract-ocr.github.io/tessdoc/Data-Files-in-different-versions.html

To add additional language you shold perform the following steps on Control Server machine:

Find out the OCR container Id:

Downloading Installation Package

$ docker ps -a | grep ocr
d63f6dbbcbfe	 ci.rpaplatform.org:8080/rpaplatform/easy-rpa-ocr:3.1.0-SNAPSHOT			"java -cp @/app/jib-…"	 13 days ago	 Up 13 days				 0.0.0.0:8848->8848/tcp, :::8848->8848/tcp
														easy-rpa-cs-ocr-1

Connect to OCR contaier and install the languages:

Downloading Installation Package

$ docker exec -it --user root d63f6dbbcbfe /bin/bash
root@d63f6dbbcbfe:/app# apt-get update && apt-get install -y tesseract-ocr-XXX

where the XXX is the language code you need to add.

Scaling OCR containers

Overview

Platforms OCR feature is quite resource consuming. Default installation provides only one OCR container. Depending on machine performance and business need, it is possible to:

increase/decrease a number of OCR containers on the CS's machine.
add external OCR containers on a separate dedicated machine.

Scaling OCR Containers On the CS's machine

The following command set 3 OCR container running on the CS's machine:

$ docker-compose scale ocr=3 && docker-compose restart telegraf

Checking OCR Performance

You need to take care about CS's machine performance balance - adding more OCR containers provides speed for parallel document processing till there are enough CPU and memory machine resources. Otherwise it could brake CS performance till dramatical results.

Use the Monitoring view to analyze the CS's machine performance:

Adding External OCR Containers On A Dedicated Machine

Use self-extracting installation package "rpaplatform-extra-install.sh" from a CS server instance folder. Package is already preset to connect the parent CS instance.

Machine Prerequisites

Linux server with Docker environment. Alternatively a Windows machine could be used with a WSL Ubuntu + Docker Desktop setup (see Installation on Windows 10 for details)
Firewall is not blocking connection to the parent CS instance
Installation package "rpaplatform-extra-install.sh" + "rpaplatform-extra-install.sh.sha256" is uploaded to server

Installing extra OCR containers

Start installation with the following command

$ sudo bash -f ./rpaplatform-extra-install.sh

Optionally you can provide following command line parameters:

--debug (enables debug output of the installation process)
--install-dir <A DIRECTORY> (submits directory for the instance to be created in)

If install directory is not provided as parameter, it needs to be entered during installation. Default suggestion is /opt/rpaplatform_ocr

Installation directory [/opt/rpaplatform_ocr]:

Migrating extra OCR containers to a new version

To migrate to a new version of OCR containers following should be done:

Parent CS instance should be migrated first - installation package "rpaplatform-extra-install.sh" will be re-generated during migration
Copy re-generated package and follow installation instructions above - old setup will be deleted and new one created

Checking OCR Performance

Use the Monitoring view to analyze the external OCR containers performance - extra containers have prefix rpaplatform_extra_<MACHINE_NAME>: