inotify-max-user-instances-exhausted-by-docker-shims

Root cause: each Docker container shim consumes ~1 inotify instance; 100+ containers exhaust the default kernel limit of 128, causing brainstorm server (and other Node.js watchers) to fail with EMFILE. Fix: create /etc/sysctl.d/99-inotify.conf with fs.inotify.max_user_instances=512 and apply with sysctl —system. Symptom is misleading — the error appears as a file-descriptor issue, not a container count issue.