15:01:08 GMT <PSUser2> anyone here?
15:01:22 GMT <PSUser2> i've got a problem with redis
15:01:50 GMT <PSUser2> 2 threads concurent access to redis queues
15:02:15 GMT <PSUser2> anyone, please?
15:02:32 GMT <PSUser2> i don't want to write the whole story any nobody's here to read
15:24:15 GMT <minus> PSUser2: redis is single threaded, so no problem on that side
15:24:28 GMT <minus> but that not being a problem should be kind of obvious anyway
15:24:41 GMT <PSUser2> do you have 2 minutes to explain you what i encounter?
15:24:47 GMT <minus> sure thing
15:25:37 GMT <minus> (but in the channel please)
15:26:27 GMT <PSUser2> while one thread reads an element from a sorted set, and moves it to another key, the other thread reads the same element, but without the score.
15:26:54 GMT <PSUser2> i've used multi/exec to read+move the element
15:27:10 GMT <PSUser2> but somehow the other thread gets to read the element that is being moved
15:27:59 GMT <minus> how do you move it? if that involves having the value client-side it won't help
15:28:23 GMT <PSUser2> i move it be recreating it
15:28:35 GMT <PSUser2> i've discovered 5 minutes ago this method
15:28:36 GMT <PSUser2> smove
15:28:41 GMT <PSUser2> maybe this will help
15:29:12 GMT <minus> that's for normal sets only
15:30:03 GMT <PSUser2> not the ones with score?
15:30:14 GMT <minus> not with sorted sets, no
15:30:28 GMT <minus> try, it'll probably give you an error
15:30:52 GMT <minus> to read+move you currently use zrangebyscore + zadd?
15:30:57 GMT <PSUser2> ok, so i move it be reading first the score, then recreating it, then deleting it from the source queue
15:31:09 GMT <PSUser2> but i have multi and exec wrapped
15:31:27 GMT <minus> that doesn't work if you need the value client-side to do that
15:31:42 GMT <minus> smove or rpoplpush-style commands would only work for that
15:32:03 GMT <minus> the other option is to do the three commands you have in a lua script. that's atomic and guarantees no other client will get the valyue
15:33:07 GMT <PSUser2> rpoplpush, does it return the element with the top score?
15:33:28 GMT <minus> that only works for lists, you can't use it on sorted sets either
15:33:34 GMT <PSUser2> ah
15:33:54 GMT <PSUser2> ok, so lua script. never heard of it. :) i'll check now
15:34:10 GMT <minus> see the EVAL command
15:49:53 GMT <PSUser2> minus, does this look legit? http://pastebin.com/J63beVwc
15:50:21 GMT <minus> you should use the KEYS for keys
15:51:21 GMT <minus> PSUser2: ZRANGE has an WITHSCORES argument you can use to get the score in one call
15:51:28 GMT <minus> otherwise it looks fine
15:51:54 GMT <PSUser2> i don;t know what do you mean by KEYS for keys
15:51:58 GMT <minus> actually, zrange returns a list, so you'll have to index into that (index 1, because lua)
15:52:28 GMT <minus> you call EVAL with two different types or arguments, ARGV and KEYS, check the docs
15:52:53 GMT <PSUser2> ok, but i don't use any keys here
15:53:09 GMT <minus> queue_src and queue_dst are keys
15:53:13 GMT <PSUser2> i only want it to return to me the top element, and move it to another queue
15:53:16 GMT <PSUser2> aaa
15:53:19 GMT <PSUser2> my bad
15:53:21 GMT <PSUser2> sorry
15:53:28 GMT <PSUser2> i'm sorry
15:53:38 GMT <minus> it's not strictly necessary, but might cause problems when working with redis cluster i think
15:54:02 GMT <minus> if you're using redis 3.2, redis-cli has a lua debugger mode, that might help
15:54:05 GMT <PSUser2> if i use zrange with -1 -1, do i still need that index?
15:54:15 GMT <minus> (i've never used it, but debugging redis lua scripts otherwise is a pain)
15:54:24 GMT <minus> it still returns a list, yes
16:16:31 GMT <PSUser2> i've managed to make the lua script to work, thank you minus
16:16:39 GMT <minus> you're welcome :)
16:16:40 GMT <PSUser2> now i'm trying to integrate it in perl
16:17:01 GMT <minus> uh, good luck with that
16:17:56 GMT <PSUser2> thank you