We're seeing a few hundred CAS errors every day on production, make sure these aren't symptom of a deeper problem.
csteipp@fluorine:/a/mw-log/archive$ zgrep -c CAS exception.log-201510[23]*.gz exception.log-20151020.gz:146 exception.log-20151021.gz:134 exception.log-20151022.gz:158 exception.log-20151023.gz:313 exception.log-20151024.gz:1486 exception.log-20151025.gz:368 exception.log-20151026.gz:630 exception.log-20151027.gz:659 exception.log-20151028.gz:350 exception.log-20151029.gz:414 exception.log-20151030.gz:291 exception.log-20151031.gz:394
=> Logstash query: https://logstash.wikimedia.org/goto/ee0b4bf7c773c18981cae04d43a3e2d9