view proxy_cache_error.t @ 1752:ba6e24e38f03

Tests: improved stop_daemons() to send signal again. As was observed, it's possible that a signal to complete a uwsgi daemon can be ignored while it is starting up, which results in tests hang due to eternal waiting on child processes termination. Notably, it is seen when running tests with a high number of prove jobs on a low-profile VM against nginx with broken modules and/or configuration. To reproduce: $ TEST_NGINX_GLOBALS=ERROR prove -j16 uwsgi*.t Inspecting uwsgi under ktrace on FreeBSD confirms that a SIGTERM signal is ignored at the very beginning of uwsgi startup. It is then replaced with a default action after listen(), thus waiting until uwsgi is ready to accept new TCP connections doesn't completely solve the hang window. The fix is to retry sending a signal some time after waitpid(WNOHANG) continuously demonstrated no progress with reaping a signaled process. It is modelled after f13ead27f89c that improved stop() for nginx.
author Sergey Kandaurov <pluknet@nginx.com>
date Wed, 29 Dec 2021 22:29:23 +0300
parents 51656beb9996
children 4f238efded81
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#!/usr/bin/perl

# (C) Maxim Dounin

# Tests for http proxy cache, "header already sent" alerts on backend errors,
# http://mailman.nginx.org/pipermail/nginx-devel/2018-January/010737.html.

###############################################################################

use warnings;
use strict;

use Test::More;

BEGIN { use FindBin; chdir($FindBin::Bin); }

use lib 'lib';
use Test::Nginx;

###############################################################################

select STDERR; $| = 1;
select STDOUT; $| = 1;

my $t = Test::Nginx->new()->has(qw/http proxy cache/)->plan(1)
	->write_file_expand('nginx.conf', <<'EOF');

%%TEST_GLOBALS%%

daemon off;

events {
}

http {
    %%TEST_GLOBALS_HTTP%%

    proxy_cache_path   %%TESTDIR%%/cache  levels=1:2
                       keys_zone=NAME:1m;

    server {
        listen       127.0.0.1:8080;
        server_name  localhost;

        location / {
            proxy_pass    http://127.0.0.1:8081;
            proxy_cache   NAME;

            proxy_read_timeout 500ms;
        }
    }

    server {
        listen       127.0.0.1:8081;
        server_name  localhost;

        location / {
            postpone_output 0;
            limit_rate 512;
            expires 1m;
        }
    }
}

EOF

$t->write_file('big.html', 'x' x 1024);

$t->run();

###############################################################################

# make a HEAD request; since cache is enabled, nginx converts HEAD to GET
# and will set u->pipe->downstream_error to suppress sending the response
# body to the client

like(http_head('/big.html'), qr/200 OK/, 'head request');

# once proxy_read_timeout expires, nginx will call
# ngx_http_finalize_upstream_request() with u->pipe->downstream_error set
# and rc = NGX_HTTP_GATEWAY_BAD_GATEWAY; after revision ad3f342f14ba046c this
# will result in ngx_http_finalize_request(NGX_HTTP_GATEWAY_BAD_GATEWAY),
# leading to an attempt to return additional error response and
# the "header already sent" alert; fixed in 93abb5a855d6

###############################################################################