You could also implement live queries using polling and the E-Tag, If-None-Match header (https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If-None-Match

You could also implement live queries using polling and the E-Tag, If-None-Match header (https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If-None-Match https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If...). We experimented with something similar on a customer project where having a long-lived HTTP connection was not possible.