[9 TH] Bitparking Pool, DGM 0%,vardiff,stratum,Merge Mining

[gog1]

Are block transaction fees associated with the block included in reward if you are mining on DGM?

[Krak]

Are block transaction fees associated with the block included in reward if you are mining on DGM?

Do you pay out BTC mining transaction fees to miners on DGM?

Not at this stage, no. I plan to run for a while and ensure that fees cover the DGM operation taking into account the fact that the pool pays for orphans - I don't think other DGM pools do this. I'll revisit the decision after that.

It was only 3 posts up.

[doublec]

On Sunday, 28 April 2013 at 09:20:00 the pool will have 5-10 minutes of downtime as my hosting provider does some network maintenance. During this time the pool won't be reachable so please ensure you have a backup set.

[Chemicalbro]

I'm not a math whiz so obviously I didn't work out the DGM formula, but can you explain this excerpt from estimated payout?

9b82df0   0.00917350   2400   1761
f4b05c10   0.00962449   2252   1652
b0b1c641   0.00865581   1912   1403
3ca5c166   0.00776793   1741   1277
62403c5c   0.02521335   1648   1209 <-----
0681e43d   0.00665353   1524   1118
ff548d9a   0.00586897   1378   1011
52671f51   0.00428931   1248   915

Why would this one be so much more? The "capacitor" that much more full? Seems strange.

[doublec]

Why would this one be so much more? The "capacitor" that much more full? Seems strange.

It'll be because they've found more shares in total and the capacitor is fuller. It also depends on when they mined. The payout they're getting will depending how much of short blocks and long blocks they participated in. Overall it'll average out. I wrote the following to help clear it up to someone in email:

It depends on the pool luck. If the pool has a lot of long blocks, as
happened in the last few blocks, then payouts will be less. This is
because DGM adjusts the variance so the pool operator doesn't bear too
much of the cost of long blocks. The payouts are then adjusted back
the other way when short blocks occur so you end up gaining it back.
If you stop mining the DGM system will continue to pay out in future
blocks until again you are back to what you would be with PPS (but
better off due to the lower fee). You can see this with the 'estimate'
on the user stats page. Even if you didn't DGM mine for a block it
remains with a value that decreases in future blocks.

Currently, over the last 6 blocks the pool has been solving blocks on
average at 2.3 times difficulty. This means the pool is paying out
2.3x as much per share as it is earning on PPS. This is why DGM rates
are appearing low at the moment. It will settle once we get a few
shorter blocks.

[pyra-proxy]

Is the pps pool and the dgm pool working together or are they mining seperately?  Does the d=x customizable difficulty work with dgm?  I took it off just in case and saw difficulty is at 16 right now, but I'd prefer to lower it if I could.

[doublec]

Is the pps pool and the dgm pool working together or are they mining seperately?  Does the d=x customizable difficulty work with dgm?  I took it off just in case and saw difficulty is at 16 right now, but I'd prefer to lower it if I could.

The d=x customizable difficulty does work with DGM. Yes, the default difficulty on the stratum servers is 16 and I recommend you lower it or increase it as needed. I'd really like to implement automatic difficulty adjustment at some point.

The PPS and DGM pools are working together. This way DGM miners don't need to wait weeks for a block to be found because of a smaller hash rate. The PPS pool contributes to DGM but when it comes to DGM payout time the PPS amount isn't paid out since miners are compensated at share submission time for the actual PPS rate. Here's an example of how that works. Currently we have a total of these shares:

Code:

PPS: 11,032.272
DGM:    387,956

The estimated DGM stats are:

Code:

All PPS miners:  27.05527705
All DGM miners:  1.07672230
Total:               28.13199935

You'll notice the estimated payment for DGM miners divided by the number of shares is an effective PPS rate of 277.5 satoshis which is slightly above the actual PPS of 272 due to the fee and the block solve luck.

[doublec]

On Sunday, 28 April 2013 at 09:20:00 the pool will have 5-10 minutes of downtime as my hosting provider does some network maintenance. During this time the pool won't be reachable so please ensure you have a backup set.

Just a reminder that the pool will be unreachable for 10 minutes or so as my service provider does some network maintenance. This happens in about 5 minutes.

[doublec]

Pool is back up. Let me know if you find any issues.

[doublec]

So, now the good news of DGM being implemented is announced...here comes the bad news. As I've mentioned before the motivation for implementing this was to reduce PPS usage to reduce pool risk and not require a large reserve to avoid pool bankruptcy. This is my current thinking on the changes to be made. Comments welcome.

With PPS the pool is taking the brunt of high variance and bad luck. This places great strain on the pool reserves. The high cost of bitcoins makes it difficult to purchase the amounts necessary to enable a stable reserve to reduce the risk of bankruptcy. To get a 1 in 100 chance of bankruptcy a 2.5% fee PPS pool needs 2,302 BTC in reserves. At 5% it needs 1,151 BTC reserve.

The risk of ruin is too high at the current 2.5% rate and I want to see the pool continue. When prices were low it wasn't so bad since I could just purchase more coins for the reserve, not so much now. To that end I plan to increase the PPS fee to 5%. This will happen in increments of about 1% per day for the next 3 days to give miners a chance to notice and either switch to DGM, which has a 1.5% fee, or change to another pool.
  
The getwork server will switch over to using the DGM method and will not offer PPS. It will by default refer stratum supporting miners to the stratum DGM server. Users that want to mine at the higher fee on the PPS server can connect directly to the PPS stratum server.

Some features to note of DGM:

• Your earnings work like a capacitor. When you start mining it needs to charge so initial earnings are lower than expected. When fully charged they reach a normal level of earning. When you stop mining you continue to receive earnings until it is discharged. The end result should be equivalent to PPS with a 1.5% fee.
• Payments are made to your balance when a block is found. If the round is short you may get more than the PPS rate. If a series of long rounds occurs then your payments may be less than PPS. Overall it will average out.
• The risk to the pool is much lower making it more likely to survive while balancing with low variance for miners. These parameters (more risk to pool, less to miners) can be tweaked and we can adjust it over time.
• At 1.5% fee you should earn more on DGM than PPS with consistent mining.
• The DGM server will continue to pay orphans as if they hadn't occurred. I'll need to monitor the orphan rate here to see if the fee needs to be adjusted for it.

The math behind the Double Geometric Method is explained in this bitcointalk post

Stratum users can switch between the 5% PPS and the 1.5% DGM any time by switching to the right server:

• DGM: stratum+tcp://mmpool.bitparking.com:4333
• DGM: stratum+tcp://stratum2.bitparking.com:4333
• DGM: http://mmpool.bitparking.com:15098
• PPS: stratum+tcp://mmpool.bitparking.com:3333
• PPS: stratum+tcp://stratum2.bitparking.com:3333

       
The alternate coins that are merge mined will continue to be paid using PPS whether you are mining on a DGM or a PPS server. I may revisit whether to change these to DGM at a later time but for now the pool has adequate reserves.

[doublec]

Yet another long block. The last 5 blocks have averaged 2.4x difficulty, ouch.

As discussed above, I've implemented the first part of the switch. The getwork mining is now on DGM and the stratum headers it sends points to the DGM stratum servers. The first PPS fee increment has happened, increasing to 3.5%. Some users have expressed concern that DGM earnings are lower than on PPS. The last 5 blocks, since announcing DGM, have averaged 2.4x difficulty which is why PPS payments seem high compared to DGM. Once we get some shorter blocks it'll even out. I've kept the alternate coin PPS rate at 2.5% for now.

[stryder]

As a reminder, you said that you will provide info about block duration. Are you working on that? Users could track pool luck and decide how to mine

[Krak]

As a reminder, you said that you will provide info about block duration. Are you working on that? Users could track pool luck and decide how to mine

Luck history has no effect on future luck.

[doublec]

As a reminder, you said that you will provide info about block duration. Are you working on that? Users could track pool luck and decide how to mine

Yes, it's on the list of things to do. It makes the "past blocks" stats a bit less useful without it.

[stryder]

As a reminder, you said that you will provide info about block duration. Are you working on that? Users could track pool luck and decide how to mine

Luck history has no effect on future luck.

Yes, you are right, but if pool luck is bigger, more miners would choose this pool. That means blocks would be found faster which is relevant for DGM. Of course, if pool luck is smaller...

[doublec]

A bitparking user not happy with the fee increase on PPS asks, Why do pools charge fees?. My response is here.

[zapeta]

A bitparking user not happy with the fee increase on PPS asks, Why do pools charge fees?. My response is here.

Personally I don't think a 1.5% pool fee on DGM is too much (of course, I wouldn't complain if it were reduced either!), especially considering you are still providing PPS payouts for the merged mining portion, you have to cover hardware costs, and for your time.  Fees on the PPS side should be set high enough to cover long rounds, whatever percentage that ends up coming out to.  I don't want to see a situation where fees paid on the DGM side are used to subsidize fees that users on the PPS side should be paying.  PPS is a very risky payout scheme for the pool operator and it would probably be best to eliminate it all together.

[firefop]

Personally I think DMG is a dead end... not good for miners but ok for the pool.

Why don't you simply use eligius' payout schema so the pool can never go broke? It's at least fair and easy to understand. My primary issue with most payment schemes are that they punish users when they have punish miners who have downtime --- more than they reward miners who don't have downtime. Which is why I only mine on pure pps or prop pools. Although I would make an exception for elegius... except I want to be able to register a username and have more stats than having to search for a payment address.

If you were to use that with the existing "lock in payment addresses" for each worker/user that would be a winner.

[kwaaak]

Switched to DGM.

Please start paying out txfees, too

[pyra-proxy]

I'm looking forward to the move to DGM... I'm hoping all the alts get that as well and maybe get 0% fee on alts :-) and after profitability evaluations take place, tx fees also get passed onto miners.  1.5% btc fee, 0% alt fees, tx fees passed on, all dgm.... I could live with that :-)