A lack of monitoring on Solr could cause bug 52148 to go unnoticed for a while (about a week).
This issue aims to have Solr monitored in such a way that "unexpected behaviour" would be noticed automatically, and <relevant roles> would be notified, so that service outages would be detected sooner and can be responded to quicker.
Version: wmf-deployment
Severity: enhancement
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=52148