I have the user IDs of the people who were actually overpaid (were able to make a successful withdrawal).  Working on contacting them now.

It was only the merged mining server.  Unfortunately, because shares were being paid 25 BTC each (even if it was only for about 1 minute, and even though reject rates were 99.9%), these erroneous payouts completely emptied the hot wallet, which was recently increased in size due to how much the pool had grown (unfortunately, with PPS, hot wallets can't be nearly as small as other methods).

PAYOUT ERRORS - A SUMMARY

Earlier this evening, the merged mining server was being moved to bitcoin 0.8.  One major problem in this was that by default, bitcoind 0.8 will redownload the blockchain in the new database format.  This started happening while the server was still online.  As a result, the pool server was passing out work for blocks from the early days of Bitcoin, where difficulty was in the single digits.

This only lasted about 2 minutes, but in that time, a huge number of users were credited for shares at low difficulties that they should not have been credited for.  These users then withdrew the funds, or an automatic payout happened.  The hot wallet was completely emptied, and the blame is entirely on me for not thinking this could have happened in the few seconds that bitcoind was redownloading the blockchain before I cancelled it and copied the complete chain from another server.



MY ACCOUNT BALANCE IS NOW NEGATIVE?

If your account balance is negative because you withdrew coins, PLEASE contact me to return them.  I can't force you to, Bitcoin has no chargebacks, but this is a significant blow to the pool in a period where luck has been terrible enough for the last week.

Payouts are currently frozen.  Something very big has broken and I need to find out what.  Some users were able to withdraw significantly more than they should have.

For clarity, I'd define the "default/standard" for BTC Guild fee policy as:  Satoshi Client (0. Default.  IE:  We do not impose a non-standard fee requirement, just whatever the most current client defaults to.

Merged Mining server is temporarily offline, sorry for the unannounced downtime.  It should be back up within 15 minutes hopefully.

Until you let miners exclusively add/remove what transactions they mine in your pool, you're not decentralized.  Last I checked, that isn't available on your pool.

In about 10 hours the PPLNS shifts will be increased from 3 million shares to 6 million to reduce per-shift variance, and also reduce the number of shifts being completed each day, in response to the huge surges in growth the pool has seen in recent weeks.  The 3 million shares worked out to roughly 1 hour per shift back at 4 TH/s.  We're now bumping up against 12 TH/s, and Avalons are definitely showing up all over which will take us even higher soon.

I will be actively monitoring the pool during the change so I can intervene if something goes wrong on the calculations.  I've been reviewing all of the reward display/calculation functions to make sure nothing is hard coded, and that the rewards should split properly when some shifts are larger than others.

Yes, 0.8 is amazing at how fast it can process blocks, and additionally how fast it responds with a template for a new block after an LP.  One thing I've noticed specifically is with more pools moving beyond 250,000 bytes, the time it takes pools to push out new work at a block change has increased dramatically, because bitcoind isn't having to re-prioritize/select as many transactions that weren't included in the prior block.

You haven't seen anything yet.  This month is going to be one hell of a ride.  Avalons are starting to show up in greater numbers.  At the very least it will be fun to see the Top 10 pools shuffle around in rank as the hash power finds new homes.

The 5 main categories I see as being useful:
  1) Max block size
  2) Min block size (Any block not this big will include ANY transaction, based on priority, regardless of fee)
  3) Priority block size (Space reserved specifically for high priority+no/low fee transactions)
  4) Minimum fee
  5) TX Discrimination (like how a few pools refuse to include transactions sent to 1dice...)


BTC Guild Settings:
  1) 750,000
  2) 150,000
  3) 100,000
  4) Standard satoshi client fee processing and transaction prioritization
  5) No transactions blocked, ignored, or throttled

I try, but I seem to keep winning

Max bet isn't up to 500 on those stakes

I'm providing the response as it relates to Bitcoin (since this is the Bitcoin forum, not Alternate Currency forum).  The same concepts apply for LTC, just on a much smaller scale since the network (and thus difficulty) is extremely small in comparison.

Solo mining is technically always the highest payout on average.  The problem is a matter of scale.  At 1 GH/s on the Bitcoin network at this difficulty, it would take you about 8 months to find a block.  You get the payment all at once, nothing before you find it.  It could take you 4 years.  It could take you 4 minutes.  But "on average" it would be around 8 months.

The question is are you willing to make a gamble with that kind of payoff time, and are you really sure the market & network speed will be roughly stable during those 8 months?  Because if you don't find a block early when network difficulty is rising, that 8 month average will keep increasing.  If the market crashes before you find your block, you'll end up with less USD/EUR/etc. than you would have if you had been mining at a pool and selling the whole time.

Think of it as lotto numbers.  The pool picks a first batch of numbers, and you fill in the second while mining for them.  Solo mining, you pick all the numbers.  So if you had been solo mining, it doesn't mean you would have found the blocks.  You may have found even more, you may not have found one yet.

If mining pools were not around, you would probably see significantly fewer miners.  I don't know many people who would like to burn that much in electricity to play in a lottery.  Without pools (assuming the same network speed) at 1 GH/s, you would on average get paid 25 BTC every ~8 months.  If you have bad luck, that could be 4+ years.  Good luck, maybe in a few minutes.

Pools allow you to avoid that kind of variance (which is terrifying these days given how much hash power is required).   And most pools offer things like email alerts when miners stop working, which means you don't need your own internal monitoring system.  They also mean you don't have to run a full bitcoind node on your LAN in order to generate coins.

If you're referring to 'Discarded Work' stat on cgminer, that is a completely useless statistic over the Stratum interface, and has no influence on performance.

A few IPs and multiple machines on a single worker are fine.  BTC Guild's automatic detection of botnets uses very permissive settings.  I do manual inspection on occasion, but the activity you described does not sound like it would be a problem.

I've had good luck on Dice over the last few weeks.  After tonight I think I'm going to call it quits while I'm in the green at ~700 BTC.  Would hate to lose it all back.