2024/01/10 14:20:15 [error] 23456#23456: *78 connect() failed (111: Connection refused) while connecting to upstream, client: 10.0.0.5, server: api.example.com, request: "GET /v1/users HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/users"
2024/01/10 14:20:16 [error] 23456#23456: *79 upstream prematurely closed connection while reading response header from upstream, client: 10.0.0.6, server: api.example.com, request: "POST /v1/auth HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/auth"
2024/01/10 14:20:17 [error] 23456#23456: *80 upstream sent too big header while reading response header from upstream, client: 10.0.0.7, server: api.example.com, request: "GET /v1/data HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/data"
2024/01/10 14:20:18 [error] 23456#23456: *81 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 10.0.0.8, server: api.example.com, request: "GET /v1/long-request HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/long-request"
2024/01/10 14:20:19 [error] 23456#23456: *82 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 10.0.0.9, server: api.example.com, request: "GET /v1/reset HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/reset"
2024/01/10 14:20:20 [warn] 23456#23456: *83 upstream server temporarily disabled while reading response header from upstream, client: 10.0.0.10, server: api.example.com, request: "GET /v1/health HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/health"
2024/01/10 14:20:21 [error] 23456#23456: *84 no live upstreams while connecting to upstream, client: 10.0.0.11, server: api.example.com, request: "GET /v1/fallback HTTP/1.1", upstream: "http://backend_pool/v1/fallback"
2024/01/10 14:20:22 [error] 23456#23456: *85 connect() failed (113: No route to host) while connecting to upstream, client: 10.0.0.12, server: api.example.com, request: "POST /v1/submit HTTP/1.1", upstream: "http://10.0.1.50:3000/v1/submit"
2024/01/10 14:20:23 [error] 23456#23456: *86 upstream timed out (60: Operation timed out) reading upstream, client: 10.0.0.13, server: api.example.com, request: "GET /v1/download HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/download"
2024/01/10 14:20:24 [error] 23456#23456: *87 upstream kept connection was closed, while connecting to upstream, client: 10.0.0.14, server: api.example.com, request: "GET /v1/cached HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/cached"
2024/01/10 14:20:25 [warn] 23456#23456: *88 upstream response is buffered to a temporary file /var/cache/nginx/proxy_temp/0000005678, client: 10.0.0.15, server: api.example.com, request: "GET /v1/large-data HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/large-data"
2024/01/10 14:20:26 [error] 23456#23456: *89 SSL_do_handshake() failed (SSL: error:1408F10B:SSL routines:ssl3_get_record:wrong version number) while SSL handshaking to upstream, client: 10.0.0.16, server: api.example.com, request: "GET /v1/secure HTTP/1.1", upstream: "https://127.0.0.1:8443/v1/secure"
2024/01/10 14:20:27 [error] 23456#23456: *90 upstream certificate verification error: (2:unable to get issuer certificate) while SSL handshaking to upstream, client: 10.0.0.17, server: api.example.com, request: "GET /v1/cert-verify HTTP/1.1", upstream: "https://127.0.0.1:8443/v1/cert-verify"
2024/01/10 14:20:28 [error] 23456#23456: *91 upstream sent invalid chunked response while reading upstream, client: 10.0.0.18, server: api.example.com, request: "GET /v1/chunked HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/chunked"
2024/01/10 14:20:29 [warn] 23456#23456: *92 upstream responded with status code 502 while reading response header from upstream, client: 10.0.0.19, server: api.example.com, request: "GET /v1/bad-gateway HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/bad-gateway"
2024/01/10 14:20:30 [error] 23456#23456: *93 upstream connection was dropped while connecting to upstream, client: 10.0.0.20, server: api.example.com, request: "POST /v1/upload HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/upload"
2024/01/10 14:20:31 [error] 23456#23456: *94 connect() failed (110: Connection timed out) while connecting to upstream, client: 10.0.0.21, server: api.example.com, request: "GET /v1/timeout-connect HTTP/1.1", upstream: "http://10.0.1.51:3000/v1/timeout-connect"
2024/01/10 14:20:32 [warn] 23456#23456: *95 upstream server is busy, client: 10.0.0.22, server: api.example.com, request: "GET /v1/queue HTTP/1.1", upstream: "http://backend_pool/v1/queue"
2024/01/10 14:20:33 [error] 23456#23456: *96 upstream connection limit reached, client: 10.0.0.23, server: api.example.com, request: "GET /v1/limited HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/limited"
2024/01/10 14:20:34 [error] 23456#23456: *97 upstream closed connection while sending request to upstream, client: 10.0.0.24, server: api.example.com, request: "PUT /v1/update HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/update"
2024/01/10 14:20:35 [warn] 23456#23456: *98 upstream gracefully shutting down, client: 10.0.0.25, server: api.example.com, request: "GET /v1/status HTTP/1.1", upstream: "http://127.0.0.1:8080/v1/status"