ngx.location.capture_multi 相较 ngx.location.capture 并没有做到并行与优化 - OpenResty Forum

ngx.location.capture_multi 相较 ngx.location.capture 并没有做到并行与优化

thinkleesion

背景：

我们工作环境中使用了，openresty ，在一次代码优化中有人提出使用capture_multi 代替 capture 可以做到并行调用子查询 https://github.com/openresty/lua-nginx-module#ngxlocationcapture_multi。我提出质疑并且查看openresty 源码，然后写了一个demo做为佐证。

具体代码：

#user nobody;

worker_processes 3;

#error_log logs/error.log;

#error_log logs/error.log notice;

#error_log logs/error.log info;

#pid logs/nginx.pid;

events {

worker_connections 1024;

}

http {

include mime.types;

default_type application/octet-stream;

#log_format main '$remote_addr - $remote_user [$time_local] "$request" '

# '$status $body_bytes_sent "$http_referer" '

# '"$http_user_agent" "$http_x_forwarded_for"';

#access_log logs/access.log main;

sendfile on;

#tcp_nopush on;

#keepalive_timeout 0;

keepalive_timeout 65;

#gzip on;

server {

listen 80;

server_name localhost;

#charset koi8-r;

#access_log logs/host.access.log main;

location ~ \.html {

# lua_code_cache off;

content_by_lua_block {

--ngx.print("{'errno':9001}")

local t1 = ngx.now()

res1, res2, res3, res4, res5, res6 = ngx.location.capture_multi{

{ "/bar", { method = ngx.HTTP_POST, body = "hello" } },

{ "/bar2", { method = ngx.HTTP_POST, body = "hello" } },

{ "/bar3", { method = ngx.HTTP_POST, body = "hello" } },

{ "/bar4", { method = ngx.HTTP_POST, body = "hello" } },

{ "/bar5", { method = ngx.HTTP_POST, body = "hello" } },

{ "/bar", { method = ngx.HTTP_POST, body = "hello" } },

}

--res1 = ngx.location.capture(

-- '/bar',

-- { method = ngx.HTTP_POST, body = 'hello' }

-- )

--res2 = ngx.location.capture(

-- '/bar2',

-- { method = ngx.HTTP_POST, body = 'hello' }

-- )

--res4 = ngx.location.capture(

-- '/bar4',

-- { method = ngx.HTTP_POST, body = 'hello' }

-- )

--res3 = ngx.location.capture(

-- '/bar3',

-- { method = ngx.HTTP_POST, body = 'hello' }

-- )

--res5 = ngx.location.capture(

-- '/bar5',

-- { method = ngx.HTTP_POST, body = 'hello' }

-- )

--res6 = ngx.location.capture(

-- '/bar',

-- { method = ngx.HTTP_POST, body = 'hello' }

-- )

local t2 = ngx.now()

ngx.print('--t1----'..t2..'----') -- 输出1487053211.321,1487053211.321

ngx.print("<br>")

ngx.print('--t2----'..t2..'----') -- 输出1487053211.321,1487053211.321

ngx.print("<br>")

ngx.print('------'..t2-t1..'----') -- 输出1487053211.321,1487053211.321

ngx.print("<br>")

ngx.print(res1.body)

ngx.print("----------")

ngx.print("<br>")

ngx.print(res2.body)

ngx.print("----------")

ngx.print("<br>")

ngx.print(res3.body)

ngx.print("----------")

ngx.print("<br>")

ngx.print(res4.body)

ngx.print("----------")

ngx.print("<br>")

ngx.print(res5.body)

ngx.print("----------")

ngx.print("<br>")

--ngx.print(res6.body)

ngx.print("----------")

ngx.print("<br>")

return

}

} #error_page 404 /404.html;

location /bar {

content_by_lua_block {

-- ngx.sleep(1)

--os.execute("sleep " .. 1)

local x = 0

for i = 1, 100000000 do

--for i = 1, 10000000000 do

x = x + i

end

ngx.say("ok")

}

}

location /bar2 {

content_by_lua_block {

--ngx.sleep(1)

--os.execute("sleep " .. 1)

local x = 0

--for i = 1, 10000 do

for i = 1, 100000000 do

--for i = 1, 10000000000 do

x = x + i

end

ngx.say("ok2")

}

}

location /bar3 {

content_by_lua_block {

--ngx.sleep(1)

local x = 0

--for i = 1, 10000 do

for i = 1, 100000000 do

--for i = 1, 10000000000 do

x = x + i

end

ngx.say("ok3")

}

}

location /bar4 {

content_by_lua_block {

--ngx.sleep(1)

--os.execute("sleep " .. 1)

local x = 0

--for i = 1, 10000 do

for i = 1, 100000000 do

--for i = 1, 10000000000 do

x = x + i

end

ngx.say("ok4")

}

}

location /bar5 {

content_by_lua_block {

--ngx.sleep(1)

--os.execute("sleep " .. 1)

local x = 0

--for i = 1, 10000 do

for i = 1, 100000000 do

--for i = 1, 10000000000 do

x = x + i

end

ngx.say("ok5")

}

}

# redirect server error pages to the static page /50x.html

#

error_page 500 502 503 504 /50x.html;

location = /50x.html {

root html;

}

# proxy the PHP scripts to Apache listening on 127.0.0.1:80

#

#location ~ \.php$ {

# proxy_pass http://127.0.0.1;

#}

# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000

#

#location ~ \.php$ {

# root html;

# fastcgi_pass 127.0.0.1:9000;

# fastcgi_index index.php;

# fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name;

# include fastcgi_params;

#}

# deny access to .htaccess files, if Apache's document root

# concurs with nginx's one

#

#location ~ /\.ht {

# deny all;

#}

}

# another virtual host using mix of IP-, name-, and port-based configuration

#

#server {

# listen 8000;

# listen somename:8080;

# server_name somename alias another.alias;

# location / {

# root html;

# index index.html index.htm;

# }

#}

# HTTPS server

#

#server {

# listen 443 ssl;

# server_name localhost;

# ssl_certificate cert.pem;

# ssl_certificate_key cert.key;

# ssl_session_cache shared:SSL:1m;

# ssl_session_timeout 5m;

# ssl_ciphers HIGH:!aNULL:!MD5;

# ssl_prefer_server_ciphers on;

# location / {

# root html;

# index index.html index.htm;

# }

#}

}

结果：

发现调用耗时没有变化，并且nginx work进程是单线程的，capture_multi，将subrequest 请求都交由当前进程执行ngx_http_lua_post_subrequest 方法，因此优化有限，lua只是通过携程做了一点点优化吧，但是当子查询做纯粹的计算的时候，根本达不到并发效果。

我的实验过程是否合理？？？麻烦大神指教

wd

hi,

看了一下没看到你是怎么得出没什么效果的，我看文档的意思是，使用 multi 的执行时间会是子请求里面最长的那个，如果不用 multi 的话，那按说应该是所有时间的和。你有计算过这个时间吗？

On Tue, Aug 6, 2019 at 3:29 PM 阮新余 <think...@gmail.com> wrote:

背景：
我们工作环境中使用了，openresty ，在一次代码优化中有人提出使用capture_multi 代替 capture 可以做到并行调用子查询 https://github.com/openresty/lua-nginx-module#ngxlocationcapture_multi。我提出质疑并且查看openresty 源码，然后写了一个demo做为佐证。

具体代码：

#user nobody;
worker_processes 3;

#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;

#pid logs/nginx.pid;

events {
worker_connections 1024;
}

http {
include mime.types;
default_type application/octet-stream;

#log_format main '$remote_addr - $remote_user [$time_local] "$request" '
# '$status $body_bytes_sent "$http_referer" '
# '"$http_user_agent" "$http_x_forwarded_for"';

#access_log logs/access.log main;

sendfile on;
#tcp_nopush on;

#keepalive_timeout 0;
keepalive_timeout 65;

#gzip on;

server {
listen 80;
server_name localhost;

#charset koi8-r;

#access_log logs/host.access.log main;

location ~ \.html {
# lua_code_cache off;
content_by_lua_block {
--ngx.print("{'errno':9001}")
local t1 = ngx.now()
res1, res2, res3, res4, res5, res6 = ngx.location.capture_multi{
{ "/bar", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar2", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar3", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar4", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar5", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar", { method = ngx.HTTP_POST, body = "hello" } },
}
--res1 = ngx.location.capture(
-- '/bar',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res2 = ngx.location.capture(
-- '/bar2',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res4 = ngx.location.capture(
-- '/bar4',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res3 = ngx.location.capture(
-- '/bar3',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res5 = ngx.location.capture(
-- '/bar5',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res6 = ngx.location.capture(
-- '/bar',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )

local t2 = ngx.now()
ngx.print('--t1----'..t2..'----') -- 输出1487053211.321,1487053211.321
ngx.print("<br>")
ngx.print('--t2----'..t2..'----') -- 输出1487053211.321,1487053211.321
ngx.print("<br>")
ngx.print('------'..t2-t1..'----') -- 输出1487053211.321,1487053211.321
ngx.print("<br>")
ngx.print(res1.body)
ngx.print("----------")
ngx.print("<br>")
ngx.print(res2.body)
ngx.print("----------")
ngx.print("<br>")
ngx.print(res3.body)
ngx.print("----------")
ngx.print("<br>")
ngx.print(res4.body)
ngx.print("----------")
ngx.print("<br>")
ngx.print(res5.body)
ngx.print("----------")
ngx.print("<br>")
--ngx.print(res6.body)
ngx.print("----------")
ngx.print("<br>")
return
}
} #error_page 404 /404.html;

location /bar {
content_by_lua_block {
-- ngx.sleep(1)
--os.execute("sleep " .. 1)
local x = 0
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok")
}
}

location /bar2 {
content_by_lua_block {
--ngx.sleep(1)
--os.execute("sleep " .. 1)
local x = 0
--for i = 1, 10000 do
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok2")
}
}

location /bar3 {
content_by_lua_block {
--ngx.sleep(1)
local x = 0
--for i = 1, 10000 do
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok3")
}
}

location /bar4 {
content_by_lua_block {
--ngx.sleep(1)
--os.execute("sleep " .. 1)
local x = 0
--for i = 1, 10000 do
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok4")
}
}

location /bar5 {
content_by_lua_block {
--ngx.sleep(1)
--os.execute("sleep " .. 1)
local x = 0
--for i = 1, 10000 do
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok5")
}
}
# redirect server error pages to the static page /50x.html
#
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}

# proxy the PHP scripts to Apache listening on 127.0.0.1:80
#
#location ~ \.php$ {
# proxy_pass http://127.0.0.1;
#}

# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
#location ~ \.php$ {
# root html;
# fastcgi_pass 127.0.0.1:9000;
# fastcgi_index index.php;
# fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name;
# include fastcgi_params;
#}

# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
}

# another virtual host using mix of IP-, name-, and port-based configuration
#
#server {
# listen 8000;
# listen somename:8080;
# server_name somename alias another.alias;

# location / {
# root html;
# index index.html index.htm;
# }
#}

# HTTPS server
#
#server {
# listen 443 ssl;
# server_name localhost;

# ssl_certificate cert.pem;
# ssl_certificate_key cert.key;

# ssl_session_cache shared:SSL:1m;
# ssl_session_timeout 5m;

# ssl_ciphers HIGH:!aNULL:!MD5;
# ssl_prefer_server_ciphers on;

# location / {
# root html;
# index index.html index.htm;
# }
#}

}

结果：
发现调用耗时没有变化，并且nginx work进程是单线程的，capture_multi，将subrequest 请求都交由当前进程执行ngx_http_lua_post_subrequest 方法，因此优化有限，lua只是通过携程做了一点点优化吧，但是当子查询做纯粹的计算的时候，根本达不到并发效果。

我的实验过程是否合理？？？麻烦大神指教

thinkleesion

我计算过时间通过浏览器查看的耗时，单个的串行的调用 capture 与一次调用capture_multi 是一样的，你可以看我conf的配置。

On Tuesday, August 6, 2019 at 4:44:15 PM UTC+8, wd wrote:

hi,

看了一下没看到你是怎么得出没什么效果的，我看文档的意思是，使用 multi 的执行时间会是子请求里面最长的那个，如果不用 multi 的话，那按说应该是所有时间的和。你有计算过这个时间吗？

On Tue, Aug 6, 2019 at 3:29 PM 阮新余 <thinkl...@gmail.com> wrote:
背景：
我们工作环境中使用了，openresty ，在一次代码优化中有人提出使用capture_multi 代替 capture 可以做到并行调用子查询 https://github.com/openresty/lua-nginx-module#ngxlocationcapture_multi。我提出质疑并且查看openresty 源码，然后写了一个demo做为佐证。

具体代码：

#user nobody;
worker_processes 3;

#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;

#pid logs/nginx.pid;

events {
worker_connections 1024;
}

http {
include mime.types;
default_type application/octet-stream;

#log_format main '$remote_addr - $remote_user [$time_local] "$request" '
# '$status $body_bytes_sent "$http_referer" '
# '"$http_user_agent" "$http_x_forwarded_for"';

#access_log logs/access.log main;

sendfile on;
#tcp_nopush on;

#keepalive_timeout 0;
keepalive_timeout 65;

#gzip on;

server {
listen 80;
server_name localhost;

#charset koi8-r;

#access_log logs/host.access.log main;

location ~ \.html {
# lua_code_cache off;
content_by_lua_block {
--ngx.print("{'errno':9001}")
local t1 = ngx.now()
res1, res2, res3, res4, res5, res6 = ngx.location.capture_multi{
{ "/bar", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar2", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar3", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar4", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar5", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar", { method = ngx.HTTP_POST, body = "hello" } },
}
--res1 = ngx.location.capture(
-- '/bar',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res2 = ngx.location.capture(
-- '/bar2',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res4 = ngx.location.capture(
-- '/bar4',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res3 = ngx.location.capture(
-- '/bar3',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res5 = ngx.location.capture(
-- '/bar5',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res6 = ngx.location.capture(
-- '/bar',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )

local t2 = ngx.now()
ngx.print('--t1----'..t2..'----') -- 输出1487053211.321,1487053211.321
ngx.print("<br>")
ngx.print('--t2----'..t2..'----') -- 输出1487053211.321,1487053211.321
ngx.print("<br>")
ngx.print('------'..t2-t1..'----') -- 输出1487053211.321,1487053211.321
ngx.print("<br>")
ngx.print(res1.body)
ngx.print("----------")
ngx.print("<br>")
ngx.print(res2.body)
ngx.print("----------")
ngx.print("<br>")
ngx.print(res3.body)
ngx.print("----------")
ngx.print("<br>")
ngx.print(res4.body)
ngx.print("----------")
ngx.print("<br>")
ngx.print(res5.body)
ngx.print("----------")
ngx.print("<br>")
--ngx.print(res6.body)
ngx.print("----------")
ngx.print("<br>")
return
}
} #error_page 404 /404.html;

location /bar {
content_by_lua_block {
-- ngx.sleep(1)
--os.execute("sleep " .. 1)
local x = 0
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok")
}
}

location /bar2 {
content_by_lua_block {
--ngx.sleep(1)
--os.execute("sleep " .. 1)
local x = 0
--for i = 1, 10000 do
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok2")
}
}

location /bar3 {
content_by_lua_block {
--ngx.sleep(1)
local x = 0
--for i = 1, 10000 do
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok3")
}
}

location /bar4 {
content_by_lua_block {
--ngx.sleep(1)
--os.execute("sleep " .. 1)
local x = 0
--for i = 1, 10000 do
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok4")
}
}

location /bar5 {
content_by_lua_block {
--ngx.sleep(1)
--os.execute("sleep " .. 1)
local x = 0
--for i = 1, 10000 do
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok5")
}
}
# redirect server error pages to the static page /50x.html
#
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}

# proxy the PHP scripts to Apache listening on 127.0.0.1:80
#
#location ~ \.php$ {
# proxy_pass http://127.0.0.1;
#}

# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
#location ~ \.php$ {
# root html;
# fastcgi_pass 127.0.0.1:9000;
# fastcgi_index index.php;
# fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name;
# include fastcgi_params;
#}

# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
}

# another virtual host using mix of IP-, name-, and port-based configuration
#
#server {
# listen 8000;
# listen somename:8080;
# server_name somename alias another.alias;

# location / {
# root html;
# index index.html index.htm;
# }
#}

# HTTPS server
#
#server {
# listen 443 ssl;
# server_name localhost;

# ssl_certificate cert.pem;
# ssl_certificate_key cert.key;

# ssl_session_cache shared:SSL:1m;
# ssl_session_timeout 5m;

# ssl_ciphers HIGH:!aNULL:!MD5;
# ssl_prefer_server_ciphers on;

# location / {
# root html;
# index index.html index.htm;
# }
#}

}

结果：
发现调用耗时没有变化，并且nginx work进程是单线程的，capture_multi，将subrequest 请求都交由当前进程执行ngx_http_lua_post_subrequest 方法，因此优化有限，lua只是通过携程做了一点点优化吧，但是当子查询做纯粹的计算的时候，根本达不到并发效果。

我的实验过程是否合理？？？麻烦大神指教

thinkleesion

并且我查看过源码，和我实验的结果一致，就是capture_multi 没有起到优化的作用

On Tuesday, August 6, 2019 at 5:27:11 PM UTC+8, GoldenMountain wrote:

我计算过时间通过浏览器查看的耗时，单个的串行的调用 capture 与一次调用capture_multi 是一样的，你可以看我conf的配置。

On Tuesday, August 6, 2019 at 4:44:15 PM UTC+8, wd wrote:
hi,

看了一下没看到你是怎么得出没什么效果的，我看文档的意思是，使用 multi 的执行时间会是子请求里面最长的那个，如果不用 multi 的话，那按说应该是所有时间的和。你有计算过这个时间吗？

On Tue, Aug 6, 2019 at 3:29 PM 阮新余 <thinkl...@gmail.com> wrote:
背景：
我们工作环境中使用了，openresty ，在一次代码优化中有人提出使用capture_multi 代替 capture 可以做到并行调用子查询 https://github.com/openresty/lua-nginx-module#ngxlocationcapture_multi。我提出质疑并且查看openresty 源码，然后写了一个demo做为佐证。

具体代码：

#user nobody;
worker_processes 3;

#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;

#pid logs/nginx.pid;

events {
worker_connections 1024;
}

http {
include mime.types;
default_type application/octet-stream;

#log_format main '$remote_addr - $remote_user [$time_local] "$request" '
# '$status $body_bytes_sent "$http_referer" '
# '"$http_user_agent" "$http_x_forwarded_for"';

#access_log logs/access.log main;

sendfile on;
#tcp_nopush on;

#keepalive_timeout 0;
keepalive_timeout 65;

#gzip on;

server {
listen 80;
server_name localhost;

#charset koi8-r;

#access_log logs/host.access.log main;

location ~ \.html {
# lua_code_cache off;
content_by_lua_block {
--ngx.print("{'errno':9001}")
local t1 = ngx.now()
res1, res2, res3, res4, res5, res6 = ngx.location.capture_multi{
{ "/bar", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar2", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar3", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar4", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar5", { method = ngx.HTTP_POST, body = "hello" } },
{ "/bar", { method = ngx.HTTP_POST, body = "hello" } },
}
--res1 = ngx.location.capture(
-- '/bar',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res2 = ngx.location.capture(
-- '/bar2',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res4 = ngx.location.capture(
-- '/bar4',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res3 = ngx.location.capture(
-- '/bar3',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res5 = ngx.location.capture(
-- '/bar5',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )
--res6 = ngx.location.capture(
-- '/bar',
-- { method = ngx.HTTP_POST, body = 'hello' }
-- )

local t2 = ngx.now()
ngx.print('--t1----'..t2..'----') -- 输出1487053211.321,1487053211.321
ngx.print("<br>")
ngx.print('--t2----'..t2..'----') -- 输出1487053211.321,1487053211.321
ngx.print("<br>")
ngx.print('------'..t2-t1..'----') -- 输出1487053211.321,1487053211.321
ngx.print("<br>")
ngx.print(res1.body)
ngx.print("----------")
ngx.print("<br>")
ngx.print(res2.body)
ngx.print("----------")
ngx.print("<br>")
ngx.print(res3.body)
ngx.print("----------")
ngx.print("<br>")
ngx.print(res4.body)
ngx.print("----------")
ngx.print("<br>")
ngx.print(res5.body)
ngx.print("----------")
ngx.print("<br>")
--ngx.print(res6.body)
ngx.print("----------")
ngx.print("<br>")
return
}
} #error_page 404 /404.html;

location /bar {
content_by_lua_block {
-- ngx.sleep(1)
--os.execute("sleep " .. 1)
local x = 0
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok")
}
}

location /bar2 {
content_by_lua_block {
--ngx.sleep(1)
--os.execute("sleep " .. 1)
local x = 0
--for i = 1, 10000 do
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok2")
}
}

location /bar3 {
content_by_lua_block {
--ngx.sleep(1)
local x = 0
--for i = 1, 10000 do
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok3")
}
}

location /bar4 {
content_by_lua_block {
--ngx.sleep(1)
--os.execute("sleep " .. 1)
local x = 0
--for i = 1, 10000 do
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok4")
}
}

location /bar5 {
content_by_lua_block {
--ngx.sleep(1)
--os.execute("sleep " .. 1)
local x = 0
--for i = 1, 10000 do
for i = 1, 100000000 do
--for i = 1, 10000000000 do
x = x + i
end
ngx.say("ok5")
}
}
# redirect server error pages to the static page /50x.html
#
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}

# proxy the PHP scripts to Apache listening on 127.0.0.1:80
#
#location ~ \.php$ {
# proxy_pass http://127.0.0.1;
#}

# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
#location ~ \.php$ {
# root html;
# fastcgi_pass 127.0.0.1:9000;
# fastcgi_index index.php;
# fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name;
# include fastcgi_params;
#}

# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
}

# another virtual host using mix of IP-, name-, and port-based configuration
#
#server {
# listen 8000;
# listen somename:8080;
# server_name somename alias another.alias;

# location / {
# root html;
# index index.html index.htm;
# }
#}

# HTTPS server
#
#server {
# listen 443 ssl;
# server_name localhost;

# ssl_certificate cert.pem;
# ssl_certificate_key cert.key;

# ssl_session_cache shared:SSL:1m;
# ssl_session_timeout 5m;

# ssl_ciphers HIGH:!aNULL:!MD5;
# ssl_prefer_server_ciphers on;

# location / {
# root html;
# index index.html index.htm;
# }
#}

}

结果：
发现调用耗时没有变化，并且nginx work进程是单线程的，capture_multi，将subrequest 请求都交由当前进程执行ngx_http_lua_post_subrequest 方法，因此优化有限，lua只是通过携程做了一点点优化吧，但是当子查询做纯粹的计算的时候，根本达不到并发效果。

我的实验过程是否合理？？？麻烦大神指教

zchao1995

Hello!

如果子请求都是计算型的任务，意义就不大了，毕竟 Nginx 每个进程只有主线程在执行事件循环处理请求。如果子请求完成一些 I/O 操作，那 caputre_multi 应该会有效果的。

thinkleesion

十分感谢，我也在猜想，openresty 使用协程对一些操作进行了挂起，但是具体的IO 类型我等一下做一些实验包括网络IO,与文件IO看一下，我再conf中试过用ngx.sleep 与 os.execute("sleep " .. n) 做过实验，想必如果需要做IO也必须是openresty 做的封装。

On Tuesday, August 6, 2019 at 5:32:11 PM UTC+8, tokers wrote:

Hello!

如果子请求都是计算型的任务，意义就不大了，毕竟 Nginx 每个进程只有主线程在执行事件循环处理请求。如果子请求完成一些 I/O 操作，那 caputre_multi 应该会有效果的。

thinkleesion

我通过子查询改用proxy upstream的方式调用，并且将每一个upstream设置一个独立的端口，用http_load 进行压测。效果如下：

single proxy

3026 fetches, 1021 max parallel, 572437 bytes, in 10.0008 seconds

189.173 mean bytes/connection

302.574 fetches/sec, 57238.9 bytes/sec

msecs/connect: 269.022 mean, 3020.23 max, 4.067 min

msecs/first-response: 1559.44 mean, 9401.86 max, 3.003 min

2396 bad byte counts

HTTP response codes:

code 200 -- 1925

multi proxy

4065 fetches, 1021 max parallel, 681905 bytes, in 10.0001 seconds

167.75 mean bytes/connection

406.495 fetches/sec, 68189.7 bytes/sec

msecs/connect: 117.222 mean, 3047.4 max, 4.061 min

msecs/first-response: 766.097 mean, 9776.42 max, 3.814 min

3196 bad byte counts

HTTP response codes:

code 200 -- 3077

同样的请求未拆分成proxy upstream时：

single

2867 fetches, 1021 max parallel, 344944 bytes, in 10.0002 seconds

120.315 mean bytes/connection

286.695 fetches/sec, 34493.8 bytes/sec

msecs/connect: 180.252 mean, 3042.2 max, 4.31 min

msecs/first-response: 1162.6 mean, 9417.37 max, 3.391 min

1341 bad byte counts

HTTP response codes:

code 200 -- 1940

multi

2624 fetches, 1021 max parallel, 276846 bytes, in 10.0002 seconds

105.505 mean bytes/connection

262.395 fetches/sec, 27684 bytes/sec

msecs/connect: 821.346 mean, 4308.39 max, 4.281 min

msecs/first-response: 1086.87 mean, 7551.03 max, 40.953 min

1387 bad byte counts

HTTP response codes:

code 200 -- 1558

由此可以看出拆分出多个upstream（端口）比同一端口使用子查询效果要好，并且多个upstream中使用multi_capture 具有优化的效果，同一端口使用并且子查询的计算型操作较多，multi_capture优化效果不大。

On Tuesday, August 6, 2019 at 5:37:09 PM UTC+8, GoldenMountain wrote:

十分感谢，我也在猜想，openresty 使用协程对一些操作进行了挂起，但是具体的IO 类型我等一下做一些实验包括网络IO,与文件IO看一下，我再conf中试过用ngx.sleep 与 os.execute("sleep " .. n) 做过实验，想必如果需要做IO也必须是openresty 做的封装。

On Tuesday, August 6, 2019 at 5:32:11 PM UTC+8, tokers wrote:
Hello!

如果子请求都是计算型的任务，意义就不大了，毕竟 Nginx 每个进程只有主线程在执行事件循环处理请求。如果子请求完成一些 I/O 操作，那 caputre_multi 应该会有效果的。