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It would be super nice if redis-lua development would keep up-to-date (more or less) with current Redis development.

Redis 2.0 is officially stable now and antirez strongly encourages the use of Redis 2.0 instead of 1.2.

For support hash command need another multibulk version:

if #args == 1 and type(args[1]) == 'table' then
    for k, v in pairs(args[1]) do

pls., add multibulk2 and change args[1] to args[2]

There is no close method or similar function for connection to redis. Does it cause any problems? Thanks!

With redis-3.2.1 (python library) I get the following error:

/usr/local/lib/python3.7/site-packages/redis_lua/script.py in <module>
     17 from functools import partial
     18 from redis.client import Script as RedisScript
---> 19 from redis.client import BasePipeline
     20
     21 from .exceptions import error_handler

ImportError: cannot import name 'BasePipeline' from 'redis.client' (/usr/local/lib/python3.7/site-packages/redis/client.py)

With redis-2.10.6 not.

Hi,

In redis-cli I use command:
> zrevrangebyscore key value 0 LIMIT 0 1

How to use the same in redis-lua?

the below code does not work with redis-lua because redis:pipeline() consider the variable "key" and "otherkey" as redis command instead of being part of the command parameter list.
Or am I missing something?
[quote]
local key="foo"
local otherkey="bar"
val1,val2 = lRedis:pipeline(function()
set_cardinality("k:" .. key .. ":list")
get("k:" .. otherkey .. ":val")
end)
lua: test.lua:x: unknown redis command: key
[/quote]

Given the code:

local client = redis.connect('redis://localhost:6379/9')

The expected result is that database #9 is either selected, or the connect should fail. This is standard in many other client libs for Redis.

This is similar to issue #44, where a password in the URL is also ignored.

Hi all,

I am a Lua 5.3 user and wonder if Lua 5.3 is supported by this lib.

Thanks

How about support for ReJSON https://oss.redislabs.com/redisjson/

list-max-ziplist-entries was removed (in 3.2-rc1 as far as I can tell). I cannot immediately figure out a different key that has been stable over a long time to replace it with. Alternatively we could make the test conditional on < versus > 3.2 and replace it with hash-max-ziplist-entries which exists at least in 3.2.5 and current unstable.

in redis.lua file, pipeline function Line 516
request is {}, empty, so #request get 0, it's a bad argument for table.insert

local REDIS = require 'redis'
local redis = REDIS.connect('127.0.0.1', 6379)
local v = redis:eval("local v = redis.call('get',KEYS[1]) return v",1,"v")
print(v)

v is 'nil' even though the command appears to be successful (no error thrown).

The same EVAL in redis-cli works ok....

127.0.0.1:6379[1]> set v value
OK
127.0.0.1:6379[1]> eval "local v = redis.call('get',KEYS[1]) return v" 1 "v"
"value"
127.0.0.1:6379[1]>

Am I misunderstanding the implementation of EVAL in your library? Is it even possible to get return values out of a script?

Best regards and thanks for a great library ... I'd just love to improve my work by using scripts as I'm reaching the limits of what I can do with transactions.

The package name is "Redis" while the file name is "redis.lua", which breaks usage like below:

local Redis = require "redis"
local redis = Redis.connect(...)

We'll get the error message: "attempt to index local 'Redis' (a boolean value)".

Hopefully you can do me a favor by fixing this ;)

Thanks!
-agentzh

example:
I issue command: redis:ping(), connection drops, it takes around 10s for main thread to resume, are there any workarounds?

it would be nice to have it as non-blocking library, where you could issue
commands like that

local callback=function(event)
local response=event.response
if response=="PONG" then return "pong"
elseif response=="TIMEOUT" then --do time-out-case stuff here --
elseif response=="ERROR" then --do error-case stuff here --
end
end

redis:ping(callback)

Hey guys thanks for all the good work. I am trying to connect to a Heroku Redis server using the provide URI but I am getting back an error. I am using the following:

redis.connect(redis://username:paswword@host:port)

But this just gives me back the following error:

lua: /usr/local/share/lua/5.2/redis.lua:380: redis error: NOAUTH Authentication required

Is it not possible to use the URI, or is there another way I should be trying to connect using the URI's provided data.

i check the lua redis client in https://github.com/agentzh/lua-resty-redis, it support 100% nonblocking behavior. because it uses cosocket api,

dose this client api support non blocking

thanks

Are there any plans to add support for connecting to a redis cluster? (Establish connections to all servers and select server based on a key hash)

Hi,
When redis down, connect function will failed without giving any return value.
How to handle this situation?
Thanks

I got a lot of Lua logic that need to write/read Redis in multiple thread(C call Lua). My original Redis-C client hold a connect pool with redis. Do I need the connect pool in redis-lua? or does the connect pool was required in redis-lua?

Is this library have a concept of connect pool? Do I need to mind the dispose of the connection?

Lua 5.1.5  Copyright (C) 1994-2012 Lua.org, PUC-Rio
> redis =require 'redis'
> r = redis.connect()
> =r:get('foo')
bar
> r:set(nil, 'bar')

it never returns. On the wire we see

*3
$3
SET
$3
bar

i.e. the key is simply skipped and Redis is waiting for the third argument.

Version is 2.0.4-1 from luarocks.

I might have overlooked something but I think redis-lua doesn't support Unix Sockets. Do you think it would be possible to add support for them?

I'm wondering whether you have considered adding luvit support, now that a stable branch exists. Any thoughts?

Thanks for the great Lua library, we use it throughout our application.

One feature we'd love to see is pub/sub support. At present, we're sending out the same data N times, once for each worker. It would be great to move that to a pub/sub system in the future.

Thanks very much!

I can only seem to connect to redis db 0.

I would like to connect to the redis db at index 15 at this uri redis://localhost:6379/15.

is this possible? if I was to open a PR to make this happen, where would changes need to be made?

Does this pipeline provide command for hmset in order to improve performance of using hmset to store large amounts of data in lua?

I have implemented the Redis pool. But sometimes (maybe 1 hour) the connection within the pool will fail to execute commands(Redis is running, not down), I think the connection is closed(may be by server or client), is there any way to maintain a longtime(maybe forever) connection?

redis-lua doesn't seem to be working with Lua 5.1.4, version that I'm using in my project.
when I try to connect, I get this error:

error loading module 'socket.core' from file '/usr/local/lib/lua/5.1/socket/core.so':
    dlopen(/usr/local/lib/lua/5.1/socket/core.so, 2): Symbol not found: _luaL_prepbuffsize
  Referenced from: /usr/local/lib/lua/5.1/socket/core.so
  Expected in: flat namespace
 in /usr/local/lib/lua/5.1/socket/core.so
stack traceback:
    [C]: ?
    [C]: in function 'require'
    /usr/local/share/lua/5.1/socket.lua:12: in main chunk
    [C]: in function 'require'
    /usr/local/share/lua/5.1/redis.lua:793: in function 'create_connection'
    /usr/local/share/lua/5.1/redis.lua:836: in function 'connect'
    stdin:1: in main chunk
    [C]: ?

As I'd like to deploy the fix for #29.

I use redis_connect(ip, port) to connect the Redis server(long time connection), then it works well, but about 10 minutes later,the connection is closed(active or passive, I don't know)

false : lua_scripts/lib/redis.lua:264: connection error: closed

And all the successive command are failed. I have browsed the out put of CLIENT LIST, and not list my client's IP, why this happened?

Hello.
Try to get some value from my db

print(client:select(0)) -- return true

value={}
value=client:hkeys("myhashtabe") -- like key field1 val1 field2 val2
for k,v in pairs(value) do
print(k.." "..v) -- return nothing
end

If I do this from redis-cli - everything works

redis_version:2.8.16

From the protocol docs:

The client library API should not return an empty string, but a nil object, when the server replies with a Null Bulk String. For example a Ruby library should return 'nil' while a C library should return NULL (or set a special flag in the reply object), and so forth.

There is no language on nils in commands, and sending an actual nil makes Redis complain. This leads me to believe there is simply no valid situation in which you pass nil to a command. Because of that, I think the 'map to empty' fix for #29 is wrong.

Exception in thread "main" com.naef.jnlua.LuaRuntimeException: D:\workspaces\luaWrokspace\test\src\redis.lua:793: attempt to index a boolean value
at com.naef.jnlua.LuaState.lua_pcall(Native Method)
at com.naef.jnlua.LuaState.call(LuaState.java:555)
at org.eclipse.ldt.support.lua51.internal.interpreter.JNLua51Launcher.run(JNLua51Launcher.java:128)
at org.eclipse.ldt.support.lua51.internal.interpreter.JNLua51DebugLauncher.main(JNLua51DebugLauncher.java:24)

Lua 5.0.3

Requiring redis.lua throws the error

/.../redis.lua:57: unexpected symbol near `...'

i read the readme file but there is no docs for expire time of key
client:set('foo', 'bar')

how to set expire time for key "foo" about 3 minutes

thank you

Currently ZRANGE ... WITHSCORES returns scores as strings. Since Redis scores are always float, would it not be a good idea to call tonumber() on them before returning them to the user?

Since Lua uses cooperative multitasking and is single-threaded in most environments, libraries like LuaSocket depend heavily on timeouts and doing small batches of work at a time.

As a Redis subscriber, I have a similar requirement, and want to receive notifications within a function call that has a max-runtime duration budget. So I set a LuaSocket timeout:

client.network.socket:settimeout(0.25)
for message, abort in client:pubsub({subscribe=topics}) do
  -- Handle message and abort
  if (my elapsed time budget is up) then return end
end

But the client library is currently unforgiving of LuaSocket timeout errors and treats them like a hard failure:

lua: .///mytestfile.lua:46: /usr/local/share/lua/5.2/redis.lua:271: attempt to index local 'payload' (a nil value)

Otherwise we're missing commands like SCAN, HSCAN etc.

Thanks

Lack of auto-reconnect causes major unreliability in production.

Why is that there is no re-connect like redis-rb?

One trivial solution is every time the client is called, to check for a live connection:

redis_client = Redis.connect('127.0.0.1', 6379)
function redis()
  local ok, err = pcall(redis_client:ping())
  if not ok then redis_client = Redis.connect('127.0.0.1', 6379); end

  return redis_client;
end

There are two problems with this approach:

• Keep calling pcall(redis_client:ping()) is not efficient.
• This does not work for the pubsub subscriber case.

I know this is not an active project, but I thought I'd report the error anyway.

The hmget command fails to retrieve a second argument if the first argument is nil. For example:

redis = require('redis')

local client = redis.connect()
client:hset(1, 'exists', 'yay!')
local _, exists = client:hmget(1, 'notexists', 'exists')
print(exists) -- should print 'yay!', but doesn't

You use tostring to convert numbers to the Redis protocol format. This does not work correctly with integers above 10^14:

> =tostring(10^14-1)
99999999999999
> =tostring(10^14)
1e+14

It is possible to support numbers up to about 2^53, i.e. about 9*10^15, by using string.format instead:

> =string.format("%d",10^14)
100000000000000

Everything above 2^53-1 or below 2^53+1 is dangerous anyway, because you start seeing this:

> x = 2^53
> =(x == x+1)
true

Not sure how the client should handle this.

I've been actively using your redis-lua library in my company's project. It's cool and simple, thanks for sharing it. Primarily we use it in lua script which is a plugin for advanced MTA, we're using. The problem we're experiencing is quite a number of segfaults (perhaps in luasocket) while creating connections to redis. Have you experienced such a behaviour? Maybe you can point me to some known bugs of luascoket.

Another thing, I've made a minor patch to you library setting timeout(1) for tcp socket in connect method.

Any insight would be appreciated.

-Konstantin

Hi.
I not found close redis function

I have wrapped the redis command as:

-- Lua 5.1.5
local function redis_cmd(cli, cmd, ...)
    local arg = {...}

    -- XXX: add here to avoid the first arg is `nil`,
    -- but do nothing with multi-cmd mode
    if #arg > 1 then    
        print(unpack(arg))
        assert(arg[1])
    end

    cmd = string.lower(cmd)
    local ok, res = nil, nil
    if #arg > 0 then
        ok, res = pcall(cli[cmd], cli, unpack(arg))
    else
        ok, res = pcall(cli[cmd], cli)
    end

    return ok, res
end

and I call redis_cmd like that:

local redis_cli = redis.connect('192.168.1.103', 6379)
local ok, res = redis_cmd(redis_cli, 'set', nil, 1)

while the command need 2 or more parameters(i.e., lrange, set, and so on), and the key is nil, the redis_cmd will hang there without any error message. And I added a if judgement(XXX:) on this situation, but while I call multi-set like this:

local ok, res = redis_cmd(redis_cli, 'mset', 'key', 2, nil, 1)

it still hang, I think my if statement do nothing with this situation. Is it a bug in redis.lua?

Add just for more information:
After testing in LuaJIT 2.0.1, the form:

local ok, res = redis_cmd(redis_cli, 'mset', 'key', 2, nil, 1)

will not hang and return true, but the form still hang.

local ok, res = redis_cmd(redis_cli, 'set', nil, 1)

Git update hist:

    commit 61e77607a39321017a7399be644ab7d33ce5c707
    Author: Pierre Chapuis <[email protected]>
    Date:   Mon Aug 19 16:25:51 2013 +0200

        Return score as a number when parsing response from ZINCRBY.

This library, will return true or false for all calls to EXISTS. However, this is not consistent with the return value for core redis. According to the documentation:

Return value

Integer reply, specifically:

• 1 if the key exists.
• 0 if the key does not exist.

Since Redis 3.0.3 the command accepts a variable number of keys and the return value is generalized:

• The number of keys existing among the ones specified as arguments. Keys mentioned multiple times and existing are counted multiple times.

When passing multiple keys, there is no way to determine how many of the keys exist.

Please include somewhere in documentation answers on these "Frequently asked" questions (change answers if I did not guess right):

Q: Does redis-lua attempt to reestablish connection if it is lost?
A: No

Q: Is transaction() inside pipeline() supported?
A: No

Q: Is it possible to use return nil, error_message strategy instead of throwing error() on every error?
A: No.

When strict is enabled an error is encountered in redis.lua on line 334.

redis.lua:334: assign to undeclared variable 's_argument'