Topic: [9 TH] Bitparking Pool, DGM 0%,vardiff,stratum,Merge Mining - page 65. (Read 163780 times)

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.

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.

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

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.

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:


The estimated DGM stats are:


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.

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.

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:

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.

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.

It was only 3 posts up.

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

WAY off topic I know but long time BitParking user here and I generally leave my stats page open...well, always...and I was wondering...with the recent changes to the stats page...how hard might it be to add a silly option like some sort of live chat with other members who are lame, I mean awesome like me and leave their stats page open all day long...



Just a couple pennies worth of silly...thanks for listening and keep up the great work!

Congrats to the last two 50k score DGM winners, '70421325' and '227164b6', who got paid a 2 BTC and 1 BTC bonus respectively. Thanks to all for participating!

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.

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

They still use PPS. Mining on DGM will still earn the alt coins but the rewards for them are given using PPS. I may offer DGM for them later but I'll see how DGM goes with BTC for now.

How are altcoin payments processed for DGM users? Are they still using PPS, or is it possible to use the same DGM score for those?

Congrats to number 3 in the 50k DGM club, '6600bcec', who has been paid a 4 BTC bonus. Yes, it was supposed to be 3 BTC but I misclicked, oops. Only two to go and the next share values close to 50k are close. 21560, 20452, 20128 and 17,853.

Congrats to '255e8151' who hit 50,000 shares and has been paid a 4BTC bonus. The next 3 getting close to 50k have share values of 45400, 20,800, and 19,800.

I've made the necessary pool changes to make the DGM share count accurate and this will be rolled out after the next block or so. You'll then see the number of shares for the DGM payments and the PPS payments separately on the page and the API.

Yes, good idea. I'll add that.