Do you know maximum POST size of RUM beacon?
We saw 403 error of "/rb_<ID>".
We think it is because that there is maximum POST size rule on WAF.
We are planning to change maximum POST size from 4KB to 1MB.
Do you think it is enough to POST RUM beacon?
Answer by Gernot R. ·
the default max size of a beacon is 30kb, if it would grow higher than that it's split into multiple requests. the default limit can be configured using the `custom configuration properties` textbox within the advanced application configuration. just enter `msl=<size-in-bytes>`, so in your case `msl=4000` to decrease this limit. expect an higher amount of beacons though, since the beacon will be split if the content grows beyond 4kb.
Answer by Julius L. ·
This depends on the data actually sent in the beacon and also depends if session replay is enabled for the application or not. But even a complex user action with many resource timing data might result in beacons with size over 4kB.
Why are you limiting post size to 4kB in the first place? Does this come from any security policy in your organization?