Implement Stratum protocol for share difficulty

[Nexus9090]

Recently started minining using a BitAxe Gamma on eusolo.ckpool.org

Found that the pool difficulty issued to it is on the low side, typically between 900-1100, I was expecting the pool to issue difficulty in the region of 2000-3000 for 1.2TH/s

Having asked the question to -ck on Bitcointalk, he suggested that the only mining software that currently correctly supports requesting a particular difficulty is CGMiner, which is what I use on most of my rigs.

Is it possible to add the correct stratum protocol requests to adjust the requested pool difficulty for ESPMiner.

Many Thanks

Garry

[MyOwn2C]

If pool supports custom diff, then just use different port or use -d in password.
no AxeOS software changes needed.

[mutatrum]

Looking at the cgminer code a bit further, AxeOS only sends the suggest_difficulty after it has been authorised. When postponing the suggest to after that, ckpool does pick it up. There's another issue with ckpool however, that it takes about 60 seconds for the pool to actually accept the lower difficulty shares. This always happens, but now it's on the first minute of boot, instead after 5 minutes when ckpool lowers the difficulty. See this log:

I (15351) stratum_api: tx: {"id": 1, "method": "mining.configure", "params": [["version-rolling"], {"version-rolling.mask": "ffffffff"}]}
I (15361) stratum_api: tx: {"id": 2, "method": "mining.subscribe", "params": ["bitaxe/BM1370/v2.7.0-35-g42d58e7"]}
I (15381) stratum_api: tx: {"id": 3, "method": "mining.authorize", "params": ["bc1q######################################.bitaxe", "x"]}
I (15561) stratum_task: rx: {"result":{"version-rolling":true,"version-rolling.mask":"1fffe000"},"id":1,"error":null}
I (15751) stratum_task: rx: {"result":[[["mining.notify","691ac652"]],"c83b0269",8],"id":2,"error":null}
I (15761) stratum_task: rx: {"params":[10000],"id":null,"method":"mining.set_difficulty"}
I (15901) stratum_task: rx: {"params":[10000],"id":null,"method":"mining.set_difficulty"}
I (15921) stratum_task: rx: {"result":true,"error":null,"id":3}
I (15941) stratum_api: tx: {"id": 4, "method": "mining.suggest_difficulty", "params": [1000]}
I (16151) stratum_task: rx: {"params":[1000],"id":null,"method":"mining.set_difficulty"}

I (23631) asic_result: Ver: 2248A000 Nonce 82C9022C diff 10911.4 of 10000.
I (23631) stratum_api: tx: {"id": 5, "method": "mining.submit", "params": ["bc1q######################################.bitaxe", "679d5e0200047c7e", "0f00000000b7ce3f", "681db9a1", "82c9022c", "0248a000"]}
I (23841) stratum_task: rx: {"result":true,"error":null,"id":5}

I (36761) asic_result: Ver: 23F0A000 Nonce 06AB0428 diff 2331.3 of 1000.
I (36761) stratum_api: tx: {"id": 6, "method": "mining.submit", "params": ["bc1q######################################.bitaxe", "679d5e0200047c7f", "0000000000b7ce3f", "681db9bf", "06ab0428", "03f0a000"]}
I (36981) stratum_task: rx: {"reject-reason":"Above target","result":false,"error":null,"id":6}

I (40121) asic_result: Ver: 2235C000 Nonce FDD5039A diff 5201.7 of 1000.
I (40121) stratum_api: tx: {"id": 7, "method": "mining.submit", "params": ["bc1q######################################.bitaxe", "679d5e0200047c7f", "0700000000b7ce3f", "681db9bf", "fdd5039a", "0235c000"]}
I (40331) stratum_task: rx: {"reject-reason":"Above target","result":false,"error":null,"id":7}

I (41651) asic_result: Ver: 228A6000 Nonce 1259004A diff 1667.3 of 1000.
I (41651) stratum_api: tx: {"id": 8, "method": "mining.submit", "params": ["bc1q######################################.bitaxe", "679d5e0200047c7f", "0a00000000b7ce3f", "681db9bf", "1259004a", "028a6000"]}
I (41861) stratum_task: rx: {"reject-reason":"Above target","result":false,"error":null,"id":8}

I (42971) asic_result: Ver: 20586000 Nonce 7A6804D4 diff 16923.9 of 1000.
I (42971) stratum_api: tx: {"id": 9, "method": "mining.submit", "params": ["bc1q######################################.bitaxe", "679d5e0200047c7f", "0d00000000b7ce3f", "681db9bf", "7a6804d4", "00586000"]}
I (43181) stratum_task: rx: {"result":true,"error":null,"id":9}

I (51121) asic_result: Ver: 22342000 Nonce BF8D053E diff 2005.6 of 1000.
I (51121) stratum_api: tx: {"id": 10, "method": "mining.submit", "params": ["bc1q######################################.bitaxe", "679d5e0200047c7f", "1d00000000b7ce3f", "681db9bf", "bf8d053e", "02342000"]}
I (51331) stratum_task: rx: {"reject-reason":"Above target","result":false,"error":null,"id":10}

I (62211) asic_result: Ver: 234B0000 Nonce 7EF602E2 diff 1079.5 of 1000.
I (62211) stratum_api: tx: {"id": 11, "method": "mining.submit", "params": ["bc1q######################################.bitaxe", "679d5e0200047c7f", "3300000000b7ce3f", "681db9bf", "7ef602e2", "034b0000"]}
I (62421) stratum_task: rx: {"reject-reason":"Above target","result":false,"error":null,"id":11}

I (69561) asic_result: Ver: 217EE000 Nonce CBA20104 diff 1389.6 of 1000.
I (69561) stratum_api: tx: {"id": 12, "method": "mining.submit", "params": ["bc1q######################################.bitaxe", "679d5e0200047c80", "0600000000b7ce3f", "681db9dd", "cba20104", "017ee000"]}
I (69781) stratum_task: rx: {"result":true,"error":null,"id":12}

id 12 is the first message accepted on the 1000 difficulty, about 54 seconds after login.

I'll make a PR.

[Nexus9090]

Thanks for taking time to look into this, its appreciated.

The initial request for a suggested diff also gets ignored for the first few submissions even with CGMiner, it usually gets adopted after 4-5 shares have been submitted, so from that perspective I think the delay is pool side.

Not really an issue so long as it then later adopts the requested difficulty. I dont think the shares get rejected under CGMiner like you've described with ESP-Miner, but even so if its only the first few shares its not a big problem.

Also, hopefully you'll be able to make this a programmable option on the pool set-up page.

I was always told that the correct difficulty calculation was 2.5*GH/s so with the Gamma running around 1-1.2TH/s I'd expect to see that settle around 2000-3000

Thanks for your help.

[mutatrum]

You mean have the difficulty suggestion as a config option? That's doable. Would make it easier for people running their own pool as well, they can align the values.

[Nexus9090]

Yes, exactly.

I was just thinking it could be added as an extra field in the settings dialog page under stratum password

"Suggested Difficulty", set a default of 1000. If the box is left empty just fall back to default. That'll give best result I think.

Thanks 👍

[skot]

I think a suggest difficulty number field (with a default of 1000) in the pool settings tab of AxeOS would be awesome.

Afaik this value will need to be stored in nvs.

[mutatrum]

This has been added in #1064