Does anyone know when this Exception occure? Unfortunately it is not clear for me when the error comes up.
headers.txt (2.07 KB)

headers2.txt (9.33 KB)

I wonder what you are putting to http headers as it grows so large? When/how did the exception appear, is it coming on each request or when doing something special?

@quintessential-ibex Unfortunately I do not know exaclty what the user did. I found the error in the logfile. I only know that the user opened a screen with a grid which loaded ~20.000 rows

What is stored in the headers? Maybe is stored max. 5 cookies, thats all…

The next quesion: I do not know how to put information to headers… :wink: maybe you can tell me how to do this and I check whether I found something in my code :wink:

Vaadin itself puts almost nothing to the headers.

Setting cookies might be the case if you are doing that a lot (or with big cookies).

Grid data is sent like all vaadin client-server comms, in the http request body (or websocket).

@quintessential-ibex My cookies have only some chars (e.g. 10), not more. Do ypu have any idea what can cause the issue? Is there a way to add some logger if this happens?

@quintessential-ibex I log some dialoge switches of the user. It seems that the user stayed for some hours in the same screen, but did nothing (only browser was opened).
Maybe the long time causes the increasing header?

Sounds quite weird. Do you have Push connection on? That shouldn’t cause it either, but just trying to figure out what could be causing it.

@quintessential-ibex Push is not activated.

@quintessential-ibex Today I got the error again three times… Do you have any further ideas?

Is your application accessible from the internet? Do you have access to the access log from e.g. the reverse proxy in front of your app? Could it be possible that this is a malicious user instead of a legitimate request?

@quirky-zebra It is a “normal user”, because I have a session event listener and log the user name and the exception.

I wouldn’t trust that guy :sweat_smile:


The user has to be logged in before (with username and password)… It happend with users of different customers… :wink:

Normally Vaadin does not do heavy lifting in headers. Are you using some kind of custom security like stateless or something other not-factory like?