SAS Studio (Enterprise) might suddenly refresh itself, which exhibits the same behavior as if you clicked the refresh button on your web browser, causing the SAS Studio interface to clear. As a result, any unsaved work is lost. This issue occurs in SAS environments where a load balancer such as Amazon Elastic Load Balancer or Microsoft Azure Application Gateway is deployed between the SAS client (SAS Studio) and the SAS Web Server. If this behavior occurs, it is essential to perform a network trace using the web browser developer tools to capture this sudden refresh event.

The sudden refresh of the SAS Studio page is caused by the SAS Studio ping request failing, which causes an HTTP 5XX response from the load balancer in the network trace capture. When a SAS Studio session is active, this ping request occurs every ten seconds to check whether the current SAS Studio session is a dead or zombie session. Here is an example of that ping request:

GET https://<hostname>/SASStudio/sasexec/sessions/5a36f015-aeda-4d7a-a0a4-fc70d0c76a26/ping?dojo.preventCache=1695650262926 HTTP/2.0

If you meet the following conditions, the TCP race condition might be the cause the intermittent failure of the SAS Studio ping request, which causes the sudden SAS Studio page refresh:

• A load balancer is deployed between the SAS Web Server and Clients.
• You observe an 5XX HTTP response code for the SAS Studio ping request from the network trace.

To eliminate this race condition, you can disable the KeepAlive directive from the hostname where the SAS Web Server is deployed:

1. Create a backup of <SASCONFIG>/Lev1/Web/WebServer/conf/extra/httpd-default.conf.
2. Open the httpd-default.conf file for editing.
3. Update the KeepAlive directive from On to Off: KeepAlive Off.
4. Restart the SAS middle-tier services for this update configuration to take effect.