A connection failed

Lenses uses WebSockets and Server Side Events (SSE) to communicate with the server. Multiple connections may be happening in a page. There might be multiple reasons on why you may have a connection failing for example, internet connection dropped, your session logged out, you are behind a proxy or a firewall, etc.

In case Lenses is behind a proxy server, typical for kubernetes environments, special configuration is required to avoid connectivity issues. Please check the documentation on proxies .

Best practices


Increase the read / send timeouts to avoid connections to be closed. An adequate value to support websockets is a value higher than one hour.

Server Side Events (SSE)

SSEs are sent over traditional long-running HTTP connection. SSE suffers from a limitation to the maximum number of open connections. This limit is per browser for a domain and set to a very low number (6). Avoid opening multiple tabs which can exhaust this limit.

Also, many problems come from response buffering, enabled by default in popular proxy middlewares, breaking the real-time nature of the protocol. Lenses SSE endpoints send the response header X-Accel-Buffering: no to allow unbuffered responses, but proxy may ignore this hinting causing unexpected negative effects on the reliability of the connections. If the error persists please disable proxy buffering according to your proxy documentation.

Can’t access data from Lenses