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Nginx proxy_read_timeout по сравнению с proxy_connect_timeout

Мое взятие на Azure - то, что Облачные вычисления были модным словечком в течение нескольких лет теперь, и Microsoft имела заднее сиденье. Azure является способом Microsoft прояснить, что они думают об этом пространстве, и можно участвовать с кластером только для окон.

Я задал бы Ваш вопрос по-другому: Облачные вычисления - что-то, в чем Вы нуждаетесь или хотите? Другие ответили вполне приятно по этой теме. При выборе "да" то выяснение, которое из различных предложений является правильным ответом, является следующим шагом.

Azure могла бы получать весь шум, но EC2, конечно, получает много оплаты пользователей.

15
задан 5 July 2011 в 16:14
2 ответа

I was actually unable to reproduce this on:

2011/08/20 20:08:43 [notice] 8925#0: nginx/0.8.53
2011/08/20 20:08:43 [notice] 8925#0: built by gcc 4.1.2 20080704 (Red Hat 4.1.2-48)
2011/08/20 20:08:43 [notice] 8925#0: OS: Linux 2.6.39.1-x86_64-linode19

I set this up in my nginx.conf:

proxy_connect_timeout   10;
proxy_send_timeout      15;
proxy_read_timeout      20;

I then setup two test servers. One that would just timeout on the SYN, and one that would accept connections but never respond:

upstream dev_edge {
  server 127.0.0.1:2280 max_fails=0 fail_timeout=0s; # SYN timeout
  server 10.4.1.1:22 max_fails=0 fail_timeout=0s; # accept but never responds
}

Then I sent in one test connection:

[m4@ben conf]$ telnet localhost 2480
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
GET / HTTP/1.1
Host: localhost

HTTP/1.1 504 Gateway Time-out
Server: nginx
Date: Sun, 21 Aug 2011 03:12:03 GMT
Content-Type: text/html
Content-Length: 176
Connection: keep-alive

Then watched error_log which showed this:

2011/08/20 20:11:43 [error] 8927#0: *1 upstream timed out (110: Connection timed out) while connecting to upstream, client: 127.0.0.1, server: ben.dev.b0.lt, request: "GET / HTTP/1.1", upstream: "http://10.4.1.1:22/", host: "localhost"

then:

2011/08/20 20:12:03 [error] 8927#0: *1 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 127.0.0.1, server: ben.dev.b0.lt, request: "GET / HTTP/1.1", upstream: "http://127.0.0.1:2280/", host: "localhost"

And then the access.log which has the expected 30s timeout (10+20):

504:32.931:10.003, 20.008:.:176 1 127.0.0.1 localrhost - [20/Aug/2011:20:12:03 -0700] "GET / HTTP/1.1" "-" "-" "-" dev_edge 10.4.1.1:22, 127.0.0.1:2280 -

Here is the log format I'm using which includes the individual upstream timeouts:

log_format  edge  '$status:$request_time:$upstream_response_time:$pipe:$body_bytes_sent $connection $remote_addr $host $remote_user [$time_local] "$request" "$http_referer" "$http_user_agent" "$http_x_forwarded_for" $edge $upstream_addr $upstream_cache_status';
18
ответ дан 2 December 2019 в 20:50

The problem is that I would have expected to see some requests that timeout after proxy_read_timeout + proxy_connect_timeout, or almost that length of time, if the service is stuck and won't accept connections when Nginx tries to access it, but before Nginx can timeout - it gets released and starts processing, but is too slow and Nginx would abort because of the read timeout.

Connect timeout means TCP stalls when handshaking (for e. g., there were no SYN_ACKs). TCP would re-try sending SYNs, but you've given only to 2 sec. to Nginx to go use another Server, so it simply has no time for re-sending SYNs.

UPD.: Couldn't find in docs, but tcpdump shows that there's 3 sec. delay between 1st sent SYN and the 2nd attempt to send SYN.

3
ответ дан 2 December 2019 в 20:50

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