Frequentemente recebo 503 Service Unavailable quando tenho limit_req ativado. Nos meus registros:
[error] 22963#0: *70136 limiting requests, excess: 1.000 by zone "blitz", client: 64.xxx.xxx.xx, server: dat.com, request: "GET /id/85 H...
07.09.2012 / 06:53