For various reasons it may be necessary to manually train the bayes filter of rspamd:

• the database is corrupt
• fast learning of freshly implemented systems to shorten the learning phase
• reinitialize the database because users have made too many classification mistakes

This user guide describes how to manually train the bayes flter using collected sample spam mails.

• You need ssh access to your system or use the web app “Terminal” in Cockpit.
• You need an unpack program to unpack 7z-files
• How to install 7z-Unpack program:

   ~# yum install p7zip

• login to your system
• download Spam-Samples from http://untroubled.org/spam/
• Example:

  ~# wget http://untroubled.org/spam/2021-01.7z

• unpack samples:

  ~# 7za x 2021-01.7z

• check the current number of learned samples

  ~# rspamc stat

• remember the line total learns: 0.
• train the filter with the downloaded samples:

  ~# rspamc learn_spam 2021/*

• check the current number of learned samples again and compare it: The number of total learns should increase

• backup the rspamd-DB:

# It is better to stop Redis before you copy the file.
cp /var/lib/redis/rspamd/dump.rdb /var/lib/redis/rspamd/dump.rdb_bak_jjmmtt

• reset the bayes data (Source: Wiki)

redis-cli -s /var/run/redis-rspamd/rspamd --scan --pattern BAYES_* | xargs redis-cli -s /var/run/redis-rspamd/rspamd del
redis-cli -s /var/run/redis-rspamd/rspamd --scan --pattern RS* | xargs redis-cli -s /var/run/redis-rspamd/rspamd del

• train the bayes filter like in Use Case 1

Sometimes more in-depth information is helpful, especially when support is needed.

• current state of the service

~# systemctl status redis redis-rspamd
● redis.service - Redis persistent key-value database
   Loaded: loaded (/usr/lib/systemd/system/redis.service; disabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/redis.service.d
           └─limit.conf
   Active: active (running) since Mon 2021-02-22 18:20:20 CET; 9s ago
 Main PID: 31539 (redis-server)
   CGroup: /system.slice/redis.service
           └─31539 /usr/bin/redis-server 127.0.0.1:6379

Feb 22 18:20:20 ns-srv01.dargels.de systemd[1]: Starting Redis persistent key-value database...
Feb 22 18:20:20 ns-srv01.dargels.de systemd[1]: Started Redis persistent key-value database.

● redis-rspamd.service - Redis persistent key-value database Rspamd
   Loaded: loaded (/usr/lib/systemd/system/redis-rspamd.service; static; vendor preset: disabled)
   Active: active (running) since Mon 2021-02-22 12:30:09 CET; 5h 50min ago
 Main PID: 737 (redis-server)
   CGroup: /system.slice/redis-rspamd.service
           └─737 /usr/bin/redis-server 127.0.0.1:0

Feb 22 12:30:09 ns-srv01.dargels.de systemd[1]: Started Redis persistent key-value database Rspamd.

• example for an inactive services

~# systemctl status redis
● redis.service - Redis persistent key-value database
   Loaded: loaded (/usr/lib/systemd/system/redis.service; disabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/redis.service.d
           └─limit.conf
   Active: inactive (dead)

• functionality of the the rspamd service

~# redis-cli -s /var/run/redis-rspamd/rspamd --scan --pattern BAYES_*
BAYES_SPAM_keys
BAYES_HAM_keys

• monitor rspamd

~# redis-cli -s /var/run/redis-rspamd/rspamd monitor
OK

Wiki: https://wiki.nethserver.org/doku.php?id=howto:useful_commands#reset_bayes_data
Community:
https://community.nethserver.org/t/rspam-filter-stats-have-reset/17693/7?u=capote