I'm getting TONS of duplicate shares. What's the cause?, I didn't see that on other pools.
This can be caused by cgminer inadvertently mining two different coins at the same time, as it only maintains one block table internally.
But this would only occur
if you are not receiving enough work from your active (and in most cases primary) server,
and you have backup servers configured,
and you have not specified the FAILOVER-ONLY option -- as cgminer by default will send some work to backup pools in an attempt to keep maximize efficiency when the active server is unable to provide enough work to maximize your hashing efficiency. But if that backup server is mining a different coin, and even wafflepool's various servers are not mining the same coin at the same time, then that internal table will become corrupted and cgminer will often produce duplicate shares as a result. (Or it could also result from quotas causing same, but very few people actually try to use them so I doubt this would be relevant.)
poolwaffle is looking into a server efficiency issue right now, and based upon his past performance, he will very likely have a solution very soon.
poolwaffle, may I suggest that you try to determine if there is a correlation between the times people say they are witnessing these idle periods and the times we actually solve a block and submit it to a blockchain? As it could be very well be the same issue you noticed with the old server code wearing a different mask. e.g. solved block gets submitted to blockchain and everything stalls until it provides us with more work. If that is the case, perhaps provide us with work for a different coin in the meantime?
It seems unlikely, in fact we fixed the issue that was giving us duplicate shares on the old system (we're seeing almost none now). Some users I've seen however submit nonstop duplicate shares (literally 100%) even minutes after new work has been given (and _many_ new works given). Leading me to believe its just a very misconfigured miner.
fabrizziop, what % are you seeing of duplicate shares, and how often?
One thing I'm working through with someone else seeing their miner stall out, is with the new stratum servers we re-send the same work request after 30 seconds (some miners were disconnecting/reconnecting if they didn't hear from the server in 30 seconds - not sure why). This fixed things in testing, but it might be causing issues with other miners we hadn't tested. I've got a patch here that may fix it, but don't want to launch a new stratum immediately before going to bed, so it will go in in the morning and we'll see what that changes