My Tech-Notes

Koha Performance Tuning Guide

This guide provides recommended settings for Koha installations using Apache Prefork and Plack, based on server size, RAM, CPU cores, and expected users. It also includes steps to restart services, caching recommendations, and performance testing.

1. Apache mpm_prefork.conf

Path: /etc/apache2/mods-available/mpm_prefork.conf

Small Server (≤4GB RAM, 2 cores, <50 users)

<IfModule mpm_prefork_module>
    StartServers            2
    MinSpareServers         2
    MaxSpareServers         4
    MaxRequestWorkers       50
    MaxConnectionsPerChild  2000
</IfModule>

Medium Server (8–16GB RAM, 4–8 cores, 100–200 users)

<IfModule mpm_prefork_module>
    StartServers            3
    MinSpareServers         3
    MaxSpareServers         6
    MaxRequestWorkers       120
    MaxConnectionsPerChild  5000
</IfModule>

Large Server (32GB+ RAM, 8–16 cores, 300+ users)

<IfModule mpm_prefork_module>
    StartServers            5
    MinSpareServers         5
    MaxSpareServers         10
    MaxRequestWorkers       250
    MaxConnectionsPerChild  10000
</IfModule>

2. Koha Plack Config (koha-conf.xml)

Path: /etc/koha/sites/[instancename]/koha-conf.xml

<koha>
    <!-- Small Server -->
    <plack_max_workers>3</plack_max_workers>
    <plack_max_requests>500</plack_max_requests>

    <!-- Medium Server -->
    <!-- <plack_max_workers>5</plack_max_workers>
    <plack_max_requests>1000</plack_max_requests> -->

    <!-- Large Server -->
    <!-- <plack_max_workers>8</plack_max_workers>
    <plack_max_requests>2000</plack_max_requests> -->

    <plack_env>deployment</plack_env>
</koha>
Note: Uncomment the relevant block for your server size.

3. Restart Services

After editing the configuration files, restart Apache and Koha Plack:

# Restart Apache
sudo systemctl restart apache2

# Restart Koha Plack instance
sudo koha-plack --restart [instancename]

# Or if using systemd service
sudo systemctl restart koha-plack@[instancename].service

Verify Status

# Apache status
sudo systemctl status apache2

# Check Plack workers
ps aux | grep starman

4. Additional Tips

1. Backup Configs:

sudo cp /etc/apache2/mods-available/mpm_prefork.conf /etc/apache2/mods-available/mpm_prefork.conf.bak
sudo cp /etc/koha/sites/[instancename]/koha-conf.xml /etc/koha/sites/[instancename]/koha-conf.xml.bak

2. Monitoring:

htop
tail -f /var/log/koha/[instancename]/plack.log

3. Caching:

Consider enabling memcached for session and OPAC caching to reduce database load. This can significantly improve response times under heavy traffic.

4. Performance Testing:

Use tools like ab (ApacheBench) or wrk to simulate concurrent users and check response times:

# Example ApacheBench test: 1000 requests, 50 concurrent
ab -n 1000 -c 50 http://your-koha-server/

# Example wrk test: 30 seconds, 50 threads, 200 connections
wrk -t50 -c200 -d30s http://your-koha-server/

5. Optimization: