Limiting the maximum generated URL segment length
Restricting and Controlling PageSpeed optimization rewriting
The maximum URL size is generally limited to about 2k characters due to Internet Explorer: See http://support.microsoft.com/kb/208427/EN-US. Nginx doesn't apepar to have a limit here but Apache servers by default impose a further limitation of about 250 characters per URL segment (text between slashes). When running under Apache PageSpeed circumvents this limitation, but if you employ proxy servers in your path you may need to re-impose it by overriding the setting here. The default setting is 1024.
pagespeed MaxSegmentLength 250
pagespeed MaxSegmentLength 250;
This directive can be used in location-specific configuration sections.