Understanding the proxy_default_timeout gateway config setting.

Tyk to Upstream timeout

proxy_default_timeout specifies the amount of time that Tyk will wait for the upstream service to complete its reply to Tyk

With gateways prior to release 5.0.7 proxy_default_timeout defaulted to zero which would result in the gateway waiting forever. This consumed resources and could lead to depletion of ephemeral sockets.

Since gateway 5.0.7 proxy_default_timeout defaults to 30 seconds.

When increasing proxy_default_timeout beyond 120 seconds it is necessary to consider the client to Tyk timeouts.

Client to Tyk timeouts

http_server_options.write_timeout specifies the number of seconds that Tyk will keep the client connection open for Tyk to write to it. If this is less than proxy_default_timeout then the connection to the client will be closed and the upstream reply will not be proxied back to the client if the upstream takes longer than http_server_options.write_timeout seconds. To avoid this please make sure that http_server_options.write_timeoutis at least 1 second longer than proxy_default_timeout

http_server_options.read_timeout specifies that number of seconds that Tyk will allow the client to complete sending the request to it. This usually doesn't need to be changed since a lot of data can be sent in the default of 120 seconds, but it can be changed if needed.