Re: Question about lua-resty-redis

agentzh · 2012-07-17T02:24:32+00:00

Hello! On Sun, Jul 15, 2012 at 11:19 PM, lyerwtyr <lye...@gmail.com> wrote: > 你好貌似srcache-nginx-module 这&#x4E2A...

Re: Question about lua-resty-redis

agentzh

Hello!

On Mon, Jul 16, 2012 at 3:19 AM, Veniamin Gvozdikov wrote:
> I have a few questions about the resty redis.
>
> This's code for example:
>
> array = {"h1234", "h5678"}
>
> local res, err = red:mget(array)
> if res then
>     print("res: ", cjson.encode(res))
> end
>
> When'll mget with use the array? And I'll want out from mget:
>
> -- Output: [{"h1234":"test"}, {"h5678":"test1"}]
>

That's because the Redis server just returns the list of values
without the original keys specified in the request. See the official
redis documentation for the "mget" command:

    http://redis.io/commands/mget

I prefer keeping lua-resty-redis as thin as possible to maximize
speed. So if you really want to bind the original keys with the value
arrays, just construct the hash-like Lua table yourself ;)

BTW, I'm cc'ing the openresty mailing list:
https://groups.google.com/group/openresty/ You're very welcome to join
it and discuss openresty and nginx related questions there ;)

Best regards,
-agentzh

g.veniamin

Hello!

Thank you for reply :). I've read about openresty today. It's very
interesting, openresty included a lot extensions and any patches. I'll
try it later.

2012/7/16 agentzh <age...@gmail.com>:
> Hello!
>
> On Mon, Jul 16, 2012 at 3:19 AM, Veniamin Gvozdikov wrote:
>> I have a few questions about the resty redis.
>>
>> This's code for example:
>>
>> array = {"h1234", "h5678"}
>>
>> local res, err = red:mget(array)
>> if res then
>>     print("res: ", cjson.encode(res))
>> end
>>
>> When'll mget with use the array? And I'll want out from mget:
>>
>> -- Output: [{"h1234":"test"}, {"h5678":"test1"}]
>>
>
> That's because the Redis server just returns the list of values
> without the original keys specified in the request. See the official
> redis documentation for the "mget" command:
>
>     http://redis.io/commands/mget
>
> I prefer keeping lua-resty-redis as thin as possible to maximize
> speed. So if you really want to bind the original keys with the value
> arrays, just construct the hash-like Lua table yourself ;)
>
> BTW, I'm cc'ing the openresty mailing list:
> https://groups.google.com/group/openresty/ You're very welcome to join
> it and discuss openresty and nginx related questions there ;)
>
> Best regards,
> -agentzh



-- 
Regards,
Veniamin

g.veniamin

Hi everybody,

I have problems with resty-redis:

My testing code:

local redis = require "resty.redis"
local json  = require "cjson"
local red = redis:new()

-- local socket = "unix:/tmp/redis.sock"
-- local ok, err = red:connect(socket)

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

if not ok then
    ngx.log(ngx.ERR, socket .. ' ' .. err)
    ngx.say("failed to connect: ", err)
    return
end
result, err = red:hmset(test, name,3, ololo, 2, desc, 1)

res, err = red:hmget(test, name)
if not ok then
	ngx.say("failed to get: ", err)
	return
end

ngx.say(res)

If I'll using the hmset/hmget i haven't request.

Tcpdump output:

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on lo, link-type EN10MB (Ethernet), capture size 65535 bytes
22:35:18.141220 IP 127.0.0.1.59817 > 127.0.0.1.6379: Flags [S], seq
1761501990, win 32792, options [mss 16396,sackOK,TS val 1424521229 ecr
0,nop,wscale 5], length 0
E..<.+@.@.!.............h.c&..............@....
........
22:35:18.141233 IP 127.0.0.1.6379 > 127.0.0.1.59817: Flags [S.], seq
3856732996, ack 1761501991, win 32768, options [mss 16396,sackOK,TS
val 1424521229 ecr 1424521229,nop,wscale 5], length 0
E..<..@.@.<................Dh.c'....-.....@....
....
22:35:18.141246 IP 127.0.0.1.59817 > 127.0.0.1.6379: Flags [.], ack 1,
win 1025, options [nop,nop,TS val 1424521229 ecr 1424521229], length 0
E..4.,@.@.!.............h.c'...E...........
T.x
22:35:18.141721 IP 127.0.0.1.59817 > 127.0.0.1.6379: Flags [P.], seq
1:16, ack 1, win 1025, options [nop,nop,TS val 1424521229 ecr
1424521229], length 15
E..C.-@.@.!.............h.c'...E.....7.....
*8x
$5
hmset

22:35:18.141732 IP 127.0.0.1.6379 > 127.0.0.1.59817: Flags [.], ack
16, win 1024, options [nop,nop,TS val 1424521229 ecr 1424521229],
length 0
E..4kH@.@..y...............Eh.c6...........
T.x

It's correct output with use redis-cli:

E..<..@.@.<.............y.!....E....<c....@....
T...T.......
22:44:55.585859 IP localhost.59820 > localhost.6379: Flags [.], ack 1,
win 1025, options [nop,nop,TS val 1424665590 ecr 1424665590], length 0
E..4n.@.@..................Ey.!.....!......
T...T...
22:44:56.743897 IP localhost.59820 > localhost.6379: Flags [P.], seq
1:78, ack 1, win 1025, options [nop,nop,TS val 1424665880 ecr
1424665590], length 77
E...n.@.@..................Ey.!......u.....
T...T...*8
$5
hmset
$4
test
$4
name
$1
3
$5
ololo
$1
2
$4
desc
$1
1

22:44:56.743904 IP localhost.6379 > localhost.59820: Flags [.], ack
78, win 1024, options [nop,nop,TS val 1424665880 ecr 1424665880],
length 0
E..4..@.@...............y.!................
T...T...
22:44:56.744034 IP localhost.6379 > localhost.59820: Flags [P.], seq
1:6, ack 78, win 1024, options [nop,nop,TS val 1424665880 ecr
1424665880], length 5
E..9..@.@...............y.!..........-.....
T...T...+OK


We've HMSET without args. :(

Thank you.

-- 
Regards,
Veniamin

agentzh

Hello!

On Tue, Jul 17, 2012 at 11:46 AM, Veniamin Gvozdikov
<g.ve...@googlemail.com> wrote:
> I have problems with resty-redis:
>

Is there anything interesting in your nginx's logs/error.log file?

> My testing code:
>
> local redis = require "resty.redis"
> local json  = require "cjson"
> local red = redis:new()
>
> -- local socket = "unix:/tmp/redis.sock"
> -- local ok, err = red:connect(socket)
>
> local ok, err = red:connect("127.0.0.1", 6379)
>
> if not ok then
>     ngx.log(ngx.ERR, socket .. ' ' .. err)
>     ngx.say("failed to connect: ", err)
>     return
> end
> result, err = red:hmset(test, name,3, ololo, 2, desc, 1)
>

I don't see you assigned values to the Lua variables "test", "name",
"ololo", and "desc". Do you really mean the Lua string literals here?
That is,

    result, err = red:hmset("test", "name", 3, "ololo", 2, "desc", 1)

In your code, if you do not assign to those Lua variables, then they
all take the Lua nil value, resulting in zero arguments to the hmset
command that you've observed.

Best regards,
-agentzh

g.veniamin

Good morning,

2012/7/17 agentzh <age...@gmail.com>:
> Hello!
>
> On Tue, Jul 17, 2012 at 11:46 AM, Veniamin Gvozdikov
> <g.ve...@googlemail.com> wrote:
>> I have problems with resty-redis:
>>
>
> Is there anything interesting in your nginx's logs/error.log file?
>
>> My testing code:
>>
>> local redis = require "resty.redis"
>> local json  = require "cjson"
>> local red = redis:new()
>>
>> -- local socket = "unix:/tmp/redis.sock"
>> -- local ok, err = red:connect(socket)
>>
>> local ok, err = red:connect("127.0.0.1", 6379)
>>
>> if not ok then
>>     ngx.log(ngx.ERR, socket .. ' ' .. err)
>>     ngx.say("failed to connect: ", err)
>>     return
>> end
>> result, err = red:hmset(test, name,3, ololo, 2, desc, 1)
>>
>
> I don't see you assigned values to the Lua variables "test", "name",
> "ololo", and "desc". Do you really mean the Lua string literals here?
> That is,
>
>     result, err = red:hmset("test", "name", 3, "ololo", 2, "desc", 1)
>

Is helps me. Please fix it on github:

syntax: red:hmset(myhash, field1, value1, field2, value2, ...)

syntax: red:hmset(myhash, { field1 = value1, field2 = value2, ... })

> In your code, if you do not assign to those Lua variables, then they
> all take the Lua nil value, resulting in zero arguments to the hmset
> command that you've observed.
>
> Best regards,
> -agentzh

Thank you!


-- 
Regards,
Veniamin

agentzh

Hello!

On Tue, Jul 17, 2012 at 9:50 PM, Veniamin Gvozdikov
<g.ve...@googlemail.com> wrote:
>
> Is helps me. Please fix it on github:
>
> syntax: red:hmset(myhash, field1, value1, field2, value2, ...)
>
> syntax: red:hmset(myhash, { field1 = value1, field2 = value2, ... })
>

I don't think the documentation requres fixes. It's by intention to
use Lua variables here instead of Lua literals. Use of uninitialized
Lua variables is obviously a programming mistake for a Lua programmer
;)

Best regards,
-agentzh