Story. we change domain of forum. then bots starts reindex. But sow whats too much CPU usage on mysql process..

And found this - > much sessions slows down mysql .

SELECT * FROM phpbb_sessions  where session_browser = 'Mozilla/5.0 (compatible; YandexImages/3.0; +http://yandex.com/bots)' or session_browser = 'Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)';

where was 257000 rows

then add new bot with partial "Yandex" and delete all bot sessions.

CPU goes down by half.

GRAPH CPU usage blue.

where was about 120 request/s via workbench viewer.

Have suggestion? maybe need keep up to date some popular search engine bots?