How to increase the request header size limit Haproxy?

How to increase the header size limit in haproxy, currently the default settings allowed only 8KB.

Due to this we are facing 400 error at client side. localhost haproxy[21502]: xx.xx.xx.xx:xxxx [xx/xxx/xxxx:xx:xx:xx.xx] www-http www-http/ -1/-1/-1/-1/0 400 187 - - PR-- 411/23/0/0/0 0/0 ""

Solution

You can set the tune.maxrewrite to a higher value.
It is strongly recommended that the header should be lower then the 8KB.

Here a link which shows the header limits on different servers Maximum HTTP request header size defaults compared across web servers