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Questions tagged [getwork]

Refering to the getwork protocol used by bitcoind.

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23 votes
2 answers
28k views

What is the extraNonce?

This question helps identify the various components of the getwork "data" field, but I'm curious where the extraNonce comes from. My hunch is it's the first four bytes of the second half of the data, ...
9 votes
2 answers
52k views

What options are there to combine mining over multiple computers?

Assuming you have multiple (30+) computers, what options are there available to do a distributed solo-mine? Can I have them all checking into one bitcoin application over the network, or do I need to ...
1 vote
1 answer
157 views

Can Bitcoin Core 0.9.5 still fully sync?

Solo Linux GPU bitcoin miner here (doing it for fun not profit so please, no 'what's the point' answers). Working mining software for this purpose is far and few in between, but I have been able to ...
6 votes
1 answer
371 views

bitcoind and rollntime support

According to this page: https://en.bitcoin.it/wiki/Poolservers bitcoind's rollntime support is 'Supported, but not advertised'. I am taking that to mean that it doesn't provide the X-Roll-NTime ...
9 votes
3 answers
3k views

How do I keep my miners from doing duplicate work?

Someone has n machines to mine for bitcoins. What's the simplest way to ensure that mining work isn't duplicated? (Will separate machines naturally work on different hashes even with the same ...
1 vote
2 answers
197 views

Unable to execute getwork logic in java

I was going through this post in stack exchange How can I code a Bitcoin JSON-RPC “getwork” request in Java? I tried to write a simple snippet for just the getwork json rpc. public static void ...
0 votes
1 answer
452 views

Bitcoin pool with GETWORK support

I study bitcoin and found a simple open source miner on githab. It runs on the CPU, and uses the outdated GetWork protocol, but it's enough to study. Is there now a bitcoin pool that still supports ...
2 votes
1 answer
21k views

Cpuminer problem: empty reply from server

When I run the following command: minerd.exe -o http://eu-stratum.btcguild.com:3333 -u username_1 -p password -a sha256d -R 2 I get this: 2 miner threads started, using 'sha256d' algorithm. Binding ...
2 votes
1 answer
18k views

GUI Miner no responses to getwork, and Verification failed

I just starting with mining today I have everything set up for slush pool on GUIMiner - v2012-12-03 . I'm not sure what is wrong but this is what the console says 2013-06-21 01:37:26: Listener for "...
1 vote
1 answer
1k views

What does nonce mean?

I'm trying to learn how litecoins work (and learn new programming language at same time by writing a crappy little miner). I'm stuck with getdata. Here http://litecoin.info/wiki/Scrypt it says that ...
1 vote
0 answers
615 views

GetWork / Stratum

I want to try to use my Bitcoin miner (ANTMiner S4) to generate SHA256 hashes of arbitrary byte orders -- The first question is "is this possible?" If so, the best way I can see to do it is to ...
0 votes
1 answer
1k views

Mining: GetWork, Get Nonce, ???, Submit Hash?

I make a getwork request and get back data, hash1, midstate, and target. Mining on a KC705 development FPGA board, and following the readme.md file here: https://github.com/progranism/Open-Source-FPGA-...
1 vote
0 answers
423 views

Litecoin getwork specification, endianness

Please help me with getwork protocol for litecoin miner.There is mixed info online about endiannes of data provided by getwork and data that should be submitted to mining pools. According to https://...
0 votes
0 answers
729 views

Get work on custom solo mining software

I'm making a bitcoin solo miner, what is the URL to get the current block header a with JSON call? I also need the URL where the work will be sent if a valid solution is found. Right now I'm trying ...
3 votes
1 answer
3k views

Please explain getwork

Request: POST / HTTP/1.1 Host: de.btcguild.com:8332 Accept: */* Accept-Encoding: deflate, gzip Content-type: application/json X-Mining-Extensions: longpoll midstate rollntime submitold Content-Length:...
2 votes
1 answer
1k views

Should I use getwork or getblocktemplate

I am working on an fpga mining device just for fun. I realized that there is a getblocktemplate function which replaces the getwork Json-rpc call. So do I need to switch over to it and change all the ...
0 votes
2 answers
382 views

What is miner supposed to do when waiting for longpoll

i am coding simple miner. I succesfully implemented Getwork in basic form. Next thing is gonna be Longpolling. If i understand correctly longpoll is just connection that is waiting for next block. So,...
-2 votes
1 answer
2k views

Difference between getwork and getblocktemplate? [duplicate]

What are the differences between getwork and getblocktemplate? Who identified the need for the new protocol? Who were the primary contributors to its creation?
2 votes
1 answer
329 views

Pre-requisites for calling Getwork

I'm a novice to bitcoin trying to learn mining. I know that in order to get the value (header) to hash, you call Getwork. I have seen the bitcoin wiki page for it and read some relevant threads on ...
5 votes
3 answers
5k views

How can I code a Bitcoin JSON-RPC "getwork" request in Java?

I'm not entirely sure whether to ask this question on Bitcoin-SE or Stack Overflow, but I decided to post it here due to the direct relevancy of the question to Bitcoin and the general prominence of ...
4 votes
1 answer
798 views

Is my idea of getwork protocol for bitminer right?

I am trying to understand the idea behind getwork protocol, by sniffing my communication with a bitminter miner pool. Previously I have read the discussion here, but looking at my packets, I think ...
4 votes
2 answers
191 views

How soon does bitcoind incorporate locally solved blocks into its 'getwork' output?

If one sends a solved block to bitcoind server using getmemorypool or getwork, and right after that requests a new block using the same API call, what will the server respond with? Assuming the data ...
2 votes
1 answer
1k views

Miners - HTTP JSON-RPC or JSON-RPC?

Does the main miner software used currently use HTTP JSON-RPC, or JSON-RPC? That is, do they use HTTP calls to obtain getwork, or TCP/IP?
5 votes
1 answer
7k views

How does one mine Namecoins?

In order to mine Bitcoins, one needs to start the bitcoind with "-server" flag and later request from it a getwork to solve. Does the Namecoin client operate in the same way, or is there some specific ...
5 votes
1 answer
445 views

Getwork - can the miner increment timestamp?

When requesting getwork from bitcoind or a pool, the miner is expected to be incrementing the nonce value of the block, but can it also increment the timestamp value, or would such tempering cause a ...
2 votes
1 answer
249 views

Does the getwork id value do anything?

When sending a getwork request, one always includes an id value. Does this value have any meaning? Will it cause problems to have multiple miners use the same id? Furthermore, if I wanted to send some ...
2 votes
3 answers
1k views

Bitcoin pool and getwork data validity

Bitcoin pools need to check data returned with getwork for validity (proper hashing result, etc.). Bitcoind that issues the initial getworks is also able to perform some data checking, but it might ...
4 votes
1 answer
2k views

What are midstate and hash1 used for in mining?

The first answer here does a good job explaining how the SHA-256 function requires more than one input (an initial one is specified by to the SHA-256 specs). As far as I understand it, the "midstate" ...
2 votes
2 answers
444 views

Mining software not using Json-RPC?

Is there some mining software out there that doesn't use Json-RPC as a communication method with the mining pool? If so, what protocol are they using?
6 votes
1 answer
2k views

Example accepted getwork function input and output?

I'm looking for example getwork input and output of a successful block hash to verify a getwork client I've implemented. I'd also accept suggestions on better ways to verify this. I've looked at ...
3 votes
2 answers
138 views

Could many large forks cause a DoS attack on the miner?

Suppose it was possible to influence a miner to create many forks. My understanding is that a miner won't retransmit the fork, but will track it internally. Where is this information saved in a ...
5 votes
1 answer
2k views

What are the internal details of GetWork() .. the foundation of Bitcoin mining?

According to this answer GetWork() sends "a chunk of data containing the block data, including the randomized bits, and the nonce (the bit which the miner changes)." Can anyone provide details on ...
7 votes
1 answer
4k views

How does a miner perform hashing?

I'm trying to walk my way through the process by which a miner hashes. Let's say the getwork request returns a data field of: ...
5 votes
2 answers
7k views

Protocols for use between mining clients and mining pool servers

Which protocols are there for mining clients to communicate with mining pool servers? How do they compare?
3 votes
1 answer
754 views

How does the rate of getwork requests correlate with the hashrate of a miner?

In a setup where a standard bitcoind serves full difficulty targets to some mining nodes, how can I calculate the hashrate of a mining node from looking at the rate of getwork requests? Does this ...
6 votes
1 answer
3k views

What is the standard protocol for pools/miners?

The Bitcoin client protocol is well documented in the Bitcoin Wiki, but I can't find much on the protocol used by pools and miners. Is it described anywhere?
1 vote
1 answer
219 views

What is the origin of the data that the bitcoin algorithm operates on?

According to the bitcoin wiki, the data used comes from calling getwork. getwork is a JSON-RPC defined at https://en.bitcoin.it/wiki/Getwork as "An RPC method used by a miner to get hashing work to ...
1 vote
1 answer
265 views

Block Hashing Data

Guys I have a few points that are not clear for me. 1) In the link below it says there are some fields we have to combine and hash. However when I get a work by saying getwork from a pool. What I get ...
3 votes
1 answer
844 views

Do pool servers communicate with bitcoind, and in what capacity?

I'm trying to understand how the whole process flows. Here's how I currently understand it working. Mining client -> Pool server -> Bitcoind getwork: Mining client calls getwork from ...
-1 votes
1 answer
263 views

work source hash rate smaller than worker hash rate

Why would my Work Source hash rate be smaller than my worker output hashing rate? I'm using MBPM and my work sources Hashrate is always lower than my X6500Hotplug Hashrate. I'm just looking for a ...
1 vote
1 answer
1k views

I am unable to figure the getwork api

I called bitcoind getwork slightly earlier in the day and this is what I got: { "midstate" : "6d8b2d759123e7311c552f0c99f6d520378062ac7a14fb11f6d433779d282faf", "data" : "...
2 votes
1 answer
323 views

How are pools protected from a client "pretending" to mine?

I understand that the GetWork JSON API is used to get a block that needs to be hashed. I also understand there are many pool payout methods (PPS, etc). With regard to mining clients and the pool ...
3 votes
2 answers
2k views

Pool getwork "target"?

In a getwork request, bitcoind sends a target corresponding to the current block's bits value. Do the major pools send the same target as one would expect from bitcoind, difficulty of "1" target, or ...
2 votes
1 answer
297 views

Getwork and GetMemoryPool - why is previous block hash different?

When I called: print bitcoin.getmemorypool() print bitcoin.getwork() using Python JSON for a testnet BitcoinQT server, I got the following responces: {'previousblockhash': '...
5 votes
1 answer
1k views

In Getwork, how does one calculate the value of Hash1?

(I know the hash1 and midstate are eventually going to be deprecated, but I'm a little curious about them) In Getwork there is a field hash1. From a sample call to bitcoind I received its value as: '...
5 votes
1 answer
2k views

JSON-RPC getwork data field

I recently tried playing around with the getwork command for JSON-RPC and I'm trying to understand what I got out of it. According to the API Call List wiki entry, the "data" field should contain the ...