VIP Platform Changelog

Instrumentation changes for New Relic

We’ve rolled out instrumentation changes for New Relic. Due to the nature of the rollout, it may have caused a temporary increase in sampling percentage on November 18, 2025, between 20:20 and 20:32 UTC. Now, to troubleshoot problematic requests, a new query argument can be used: ?vip-force-trace=1. This will force a specific request to be traced and not be subject to the sampling.

New mobile_class field added to HTTP request logs

The contents of HTTP request log files that are shipped by the HTTP request Log Shipping feature will now include a mobile_class field. Its value contains the X-Mobile-Class header value populated by the VIP edge based on the request User-Agent header.

VIP File System performance improvements

We have improved the performance speeds of VIP File System PUT and DELETE requests. Uploads are now up to 5X faster and delete operations are up to 4X faster.

In addition, new global helper functions were added to a8c-files.php in VIP MU plugins: wpvip_fs_local_file_add, wpvip_fs_local_file_remove, and wpvip_fs_local_file_list. These helper functions can be used by WordPress applications to mark files to be handled by the PHP stream wrapper in the local temporary directory rather than being uploaded to the VIP File System.

Cache personalized responses now respect `max-age` values set at origin

Applications that leverage the cache personalization API can now specify a max-age value in the Cache-Control header returned by origins.

This value will be honored by the VIP edge, which will return a Cache-Control header with the private directive, to make sure only private caches can store the response, and the max-age directive containing the value set at origin.

Changed

Cache-Control headers for responses that leverage cache personalization now include the max-age value sent from origin, if available, instead of only specifying private.

New cache_segment field added to HTTP request logs

The contents of HTTP request log files that are shipped by the HTTP request Log Shipping feature will now include a cache_segment field. For applications leveraging the VIP Cache Personalization API the value of the cache_segment field is populated by the value of the vip-go-seg cookie and will otherwise be blank.