We are using session stickiness in AWS ELB to maintain session for our application on multiple instances. We are using wkhtmltopdf tool to send requests to this ELB endpoint for generating header and footer for PDF generation from HTML. We are not able to generate header and footer for PDFs which are more than 17 pages. After deep investigation it is found that ELB gives 400 Bad request error after 35 requests(18 headers and 17 footers) [Verified this error in access_logs]. This happens even when instance count is one. However, after disabling session stickiness(one instance), able to generate proper PDFs for even more than 17 pages. Not able to understand this weird behaviour of AWS ELB.
Has anyone faced similar issues with Sticky session enabled in AWS ELB.