关于redis连接池的疑问

samuelyao314

配置如下

[samuel@localhost nginx]$ cat conf/nginx.conf

worker_processes 1;

error_log logs/error.log error;

events {

worker_connections 1024;

}

http {

lua_shared_dict ngx_cache 1m;

server {

listen 8080;

lua_code_cache off;

location ~ ^/api/([\w_]+) {

content_by_lua_file lua/$1.lua;

}

源码如下 [samuel@localhost nginx]$ cat lua/test_redis.lua

-- https://moonbingbing.gitbooks.io/openresty-best-practices/content/redis/auth_connect.html

local redis = require "resty.redis"

local red = redis:new()

red:set_timeout(1000) -- 1 sec

local ok, err = red:connect("127.0.0.1", 6379)

if not ok then

ngx.say("failed to connect: ", err)

return

end

local count, err = red:get_reused_times()

ngx.log(ngx.ERR, "get_reused_times: " .. count)

local ok, err = red:set("dog", "an animal")

if not ok then

ngx.say("failed to set dog: ", err)

return

end

ngx.say("set result: ", ok)

local res, err = red:get("dog")

if not res then

ngx.say("failed to get dog: ", err)

return

end

if res == ngx.null then

ngx.say("dog not found.")

return

end

ngx.say("dog: ", res)

local ok, err = red:set_keepalive(10000, 1)

if not ok then

ngx.say("failed to set keepalive ", err)

return

end

操作如下：连续3次 curl 127.0.0.1:8080/api/test_redis

[samuel@localhost resty]$ netstat -tnp | grep 6379

(Not all processes could be identified, non-owned process info

will not be shown, you would have to be root to see it all.)

tcp 0 0 127.0.0.1:40108 127.0.0.1:6379 TIME_WAIT -

tcp 0 0 127.0.0.1:40116 127.0.0.1:6379 TIME_WAIT -

tcp 0 0 127.0.0.1:40112 127.0.0.1:6379 TIME_WAIT -

请问为什么是有3个TIME_WAIT 状态的连接啊。我的理解是应该只有1个客户度连接。

wzxjohn

看你的错误日志，你确定你的 Redis Get Set 操作成功了么？如果 Get 或 Set 失败，你的代码会直接 return，走不到连接池这句的。

On Wednesday, January 11, 2017 at 1:20:21 PM UTC+8, samuel...@gmail.com wrote:

配置如下

[samuel@localhost nginx]$ cat conf/nginx.conf
worker_processes 1;
error_log logs/error.log error;
events {
worker_connections 1024;
}

http {
lua_shared_dict ngx_cache 1m;

server {
listen 8080;

lua_code_cache off;

location ~ ^/api/([\w_]+) {
content_by_lua_file lua/$1.lua;
}

}
}

源码如下 [samuel@localhost nginx]$ cat lua/test_redis.lua

-- https://moonbingbing.gitbooks.io/openresty-best-practices/content/redis/auth_connect.html
local redis = require "resty.redis"
local red = redis:new()

red:set_timeout(1000) -- 1 sec

local ok, err = red:connect("127.0.0.1", 6379)
if not ok then
ngx.say("failed to connect: ", err)
return
end

local count, err = red:get_reused_times()
ngx.log(ngx.ERR, "get_reused_times: " .. count)

local ok, err = red:set("dog", "an animal")
if not ok then
ngx.say("failed to set dog: ", err)
return
end

ngx.say("set result: ", ok)

local res, err = red:get("dog")
if not res then
ngx.say("failed to get dog: ", err)
return
end

if res == ngx.null then
ngx.say("dog not found.")
return
end

ngx.say("dog: ", res)

local ok, err = red:set_keepalive(10000, 1)
if not ok then
ngx.say("failed to set keepalive ", err)
return
end

操作如下：连续3次   curl 127.0.0.1:8080/api/test_redis

[samuel@localhost resty]$ netstat -tnp | grep 6379
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
tcp 0 0 127.0.0.1:40108 127.0.0.1:6379 TIME_WAIT -
tcp 0 0 127.0.0.1:40116 127.0.0.1:6379 TIME_WAIT -
tcp 0 0 127.0.0.1:40112 127.0.0.1:6379 TIME_WAIT -

请问为什么是有3个TIME_WAIT 状态的连接啊。我的理解是应该只有1个客户度连接。

doujiang24

Hello,

另外需要注意的一个点：

连接池是每 worker 的，如果你开了多个 worker，那么也可能不会复用到

2017-01-11 14:57 GMT+08:00 John Stephen <wzx...@gmail.com>:

看你的错误日志，你确定你的 Redis Get Set 操作成功了么？如果 Get 或 Set 失败，你的代码会直接 return，走不到连接池这句的。

On Wednesday, January 11, 2017 at 1:20:21 PM UTC+8, samuel...@gmail.com wrote:
配置如下

[samuel@localhost nginx]$ cat conf/nginx.conf
worker_processes 1;
error_log logs/error.log error;
events {
worker_connections 1024;
}

http {
lua_shared_dict ngx_cache 1m;

server {
listen 8080;

lua_code_cache off;

location ~ ^/api/([\w_]+) {
content_by_lua_file lua/$1.lua;
}

}
}

源码如下 [samuel@localhost nginx]$ cat lua/test_redis.lua

-- https://moonbingbing.gitbooks.io/openresty-best-practices/content/redis/auth_connect.html
local redis = require "resty.redis"
local red = redis:new()

red:set_timeout(1000) -- 1 sec

local ok, err = red:connect("127.0.0.1", 6379)
if not ok then
ngx.say("failed to connect: ", err)
return
end

local count, err = red:get_reused_times()
ngx.log(ngx.ERR, "get_reused_times: " .. count)

local ok, err = red:set("dog", "an animal")
if not ok then
ngx.say("failed to set dog: ", err)
return
end

ngx.say("set result: ", ok)

local res, err = red:get("dog")
if not res then
ngx.say("failed to get dog: ", err)
return
end

if res == ngx.null then
ngx.say("dog not found.")
return
end

ngx.say("dog: ", res)

local ok, err = red:set_keepalive(10000, 1)
if not ok then
ngx.say("failed to set keepalive ", err)
return
end

操作如下：连续3次   curl 127.0.0.1:8080/api/test_redis

[samuel@localhost resty]$ netstat -tnp | grep 6379
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
tcp 0 0 127.0.0.1:40108 127.0.0.1:6379 TIME_WAIT -
tcp 0 0 127.0.0.1:40116 127.0.0.1:6379 TIME_WAIT -
tcp 0 0 127.0.0.1:40112 127.0.0.1:6379 TIME_WAIT -

请问为什么是有3个TIME_WAIT 状态的连接啊。我的理解是应该只有1个客户度连接。

--

doujiang24

Hello

我错了，没看到你配置了只有一个 worker

2017-01-11 18:45 GMT+08:00 DeJiang Zhu <douj...@gmail.com>:

Hello,

另外需要注意的一个点：
连接池是每 worker 的，如果你开了多个 worker，那么也可能不会复用到

2017-01-11 14:57 GMT+08:00 John Stephen <wzx...@gmail.com>:
看你的错误日志，你确定你的 Redis Get Set 操作成功了么？如果 Get 或 Set 失败，你的代码会直接 return，走不到连接池这句的。

On Wednesday, January 11, 2017 at 1:20:21 PM UTC+8, samuel...@gmail.com wrote:
配置如下

[samuel@localhost nginx]$ cat conf/nginx.conf
worker_processes 1;
error_log logs/error.log error;
events {
worker_connections 1024;
}

http {
lua_shared_dict ngx_cache 1m;

server {
listen 8080;

lua_code_cache off;

location ~ ^/api/([\w_]+) {
content_by_lua_file lua/$1.lua;
}

}
}

源码如下 [samuel@localhost nginx]$ cat lua/test_redis.lua

-- https://moonbingbing.gitbooks.io/openresty-best-practices/content/redis/auth_connect.html
local redis = require "resty.redis"
local red = redis:new()

red:set_timeout(1000) -- 1 sec

local ok, err = red:connect("127.0.0.1", 6379)
if not ok then
ngx.say("failed to connect: ", err)
return
end

local count, err = red:get_reused_times()
ngx.log(ngx.ERR, "get_reused_times: " .. count)

local ok, err = red:set("dog", "an animal")
if not ok then
ngx.say("failed to set dog: ", err)
return
end

ngx.say("set result: ", ok)

local res, err = red:get("dog")
if not res then
ngx.say("failed to get dog: ", err)
return
end

if res == ngx.null then
ngx.say("dog not found.")
return
end

ngx.say("dog: ", res)

local ok, err = red:set_keepalive(10000, 1)
if not ok then
ngx.say("failed to set keepalive ", err)
return
end

操作如下：连续3次   curl 127.0.0.1:8080/api/test_redis

[samuel@localhost resty]$ netstat -tnp | grep 6379
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
tcp 0 0 127.0.0.1:40108 127.0.0.1:6379 TIME_WAIT -
tcp 0 0 127.0.0.1:40116 127.0.0.1:6379 TIME_WAIT -
tcp 0 0 127.0.0.1:40112 127.0.0.1:6379 TIME_WAIT -

请问为什么是有3个TIME_WAIT 状态的连接啊。我的理解是应该只有1个客户度连接。

--

samuelyao314

redis访问是正常的，可以从curl返回看出

[samuel@localhost lua]$ curl 127.0.0.1:8080/api/test_redis

set result: OK

dog: an animal

samuelyao314

我设置的连接池大小是1。我调整成100.结果还是一样的。

[samuel@localhost lua]$ netstat -tnp | grep 6379

(Not all processes could be identified, non-owned process info

will not be shown, you would have to be root to see it all.)

tcp 0 0 127.0.0.1:44952 127.0.0.1:6379 TIME_WAIT -

tcp 0 0 127.0.0.1:44956 127.0.0.1:6379 TIME_WAIT -

tcp 0 0 127.0.0.1:44948 127.0.0.1:6379 TIME_WAIT -

tcp 0 0 127.0.0.1:44944 127.0.0.1:6379 TIME_WAIT -

我的理解，不应该是 TIME_WAIT状态啊。而且只有1个客户端连接才对

doujiang24

Hello

仔细翻了下你的配置，问题出在这里：

lua_code_cache off;

在 code_cache off 的情况下，连接池是不生效的（此时 LuaJIT 的 VM 每请求都会重新初始化了）

这个或许也应该在最佳实践里说明一下？

在 2017年1月12日上午10:27， <samue...@gmail.com>写道：

我设置的连接池大小是1。我调整成100.结果还是一样的。

[samuel@localhost lua]$ netstat -tnp | grep 6379
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
tcp 0 0 127.0.0.1:44952 127.0.0.1:6379 TIME_WAIT -
tcp 0 0 127.0.0.1:44956 127.0.0.1:6379 TIME_WAIT -
tcp 0 0 127.0.0.1:44948 127.0.0.1:6379 TIME_WAIT -
tcp 0 0 127.0.0.1:44944 127.0.0.1:6379 TIME_WAIT -

我的理解，不应该是 TIME_WAIT状态啊。而且只有1个客户端连接才对

--