Fabric Virtual network data gateways - offline

Hi h_l_de_boer​,

Besides the known certificate issue already linked, it's worth ruling out that the gateway is simply asleep. That is by design, and it is the most common reason a VNet data gateway "works for a while, then shows offline".

A VNet data gateway is a managed container that is deallocated after a period with no queries. In the UI that shows up as offline/inactive. It starts again on the next request, but that cold start can take a few minutes, and a refresh or a test connection that arrives in that window can fail.

Manage connections and gateways -> Virtual network data gateways
-> select the gateway -> Settings
-> "Inactivity time before sleep" (default is short)
-> raise it to cover the gap between your scheduled refreshes

If raising that doesn't explain it, these are the other things I would check, in order:

capacity    -> F SKU paused / scaled down overnight? gateway goes with it
              (common when the capacity is paused by automation to save cost)
subnet      -> delegated to Microsoft.PowerPlatform/vnetaccessLinks,
               enough free IPs for the number of gateway members
DNS / NSG   -> private endpoints resolve from that VNet;
               no NSG / route table change blocking outbound
certificate -> private CA SQL cert (known issue above)

A practical workaround while testing: schedule a lightweight refresh, or a pipeline Lookup on a tiny query, just before the main refresh window. The gateway is then already warm when the real load starts.

So my overall approach would be:

check gateway status right before a failure -> asleep vs truly down
asleep -> raise inactivity time before sleep / warm it up first
down   -> capacity paused? subnet IPs / delegation? DNS + NSG?
cert   -> register root CA (known issue mitigation)

AI-assisted drafting: AI was used to help structure and phrase this response. I reviewed and validated the technical content before posting.