proxy: error reading status line from remote server

[Former Member]

Hi All,

we are getting the below error in our  error_log in webserver logs

proxy: error reading status line from remote server k96pp1c1.supplier.company.com, referer: https://bidv.supp

lier.company.com/irj/servlet/prt/portal/prteventname/Navigate/prtroot/pcd!3aportal_content!2fevery_user!2fgeneral!2fdefaultDesktop!2fframeworkPages!2fframeworkpage!2fco

m.sap.portal.innerpage?buildTree=false&NavPathUpdate=false&windowId=WID1462337687142

our infrastrure

Loadbalancer --> Webserver -->  Our Portal system PP1

When we try to access some data from our portal for a long time, some of our suppliers are getting the above error.

SAP Suggested to directly connect to PP1 bypassing Loadbalancer and webserver  -- > we bypassed -- > by making siteminder_off  in visual admin

webagent=off in webserver  ---> We are not getting any Proxy error

Could you please suggest how to solve this proxy error ?

we get below error in browser

Proxy Error   

The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request POST /irj/servlet/prt/portal/prteventname/HtmlbEvent/prtroot/pcd!3aportal_content!2fadministrator!2fsuper_admin!2fsuper_admin_role!2fcom.sap.portal.content_administration!2fcom.sap.portal.content_admin_ws!2fcom.sap.km.AdminContent!2fcom.sap.km.AdminContentExplorer!2fcom.sap.km.AdminExplorer/ (/irj/servlet/prt/portal/prteventname/HtmlbEvent/prtroot/pcd%213aportal_content%212fadministrator%212fsuper_admin%212fsuper_admin_role%212fcom.sap.portal.content_administration%212fcom.sap.portal.content_admin_ws%212fcom.sap.km.AdminContent%212fcom.sap.km.AdminContentExplorer%212fcom.sap.km.AdminExplorer/).

Reason: Error reading from remote server

[Former Member]

We tried below options , still the issue exist

Webservers are on AIX  -

Changed - OS parameter   tcp_keepinit   to 2100     - initial value was 150  

SetEnv proxy-sendchunked 1  in https.conf  of webserver

Regards