MultiChain Developer Q&A - Recent questions tagged pow

Is it possible to start a new chain with a specific difficulty?

Thu, 23 Nov 2023 02:25:02 +0000

We already have a chain running using permissionless PoW. We called that the "testnet". Soon we would like to migrate to a "mainnet". Essentially, it will be just cloning the existing "testnet". All of the miners will move over to that new chain. Since we have established a good difficulty value, we would like to start the new chain with that same value. getmininginfo returns:
{
    "blocks" : 3788,
    "currentblocksize" : 1000,
    "currentblocktx" : 0,
    "difficulty" : 1.52587890625e-5,
    "errors" : "",
    "genproclimit" : 1,
    "networkhashps" : 14351024,
    "pooledtx" : 0,
    "testnet" : false,
    "chain" : "main",
    "generate" : true,
    "hashespersec" : 1015190
}

createfrom [from-address] upgrade [upgrade-name] false [new-params]

Thu, 17 Mar 2022 07:59:18 +0000

./multichain-cli.exe msis001 createfrom 1ApCtNaicZ6uYwtsoaZezPiR5ixSbmt6DJV1wz upgrade pow false {"pow-minimum-bits":9}
{"method":"createfrom","params":["1ApCtNaicZ6uYwtsoaZezPiR5ixSbmt6DJV1wz","upgrade","pow",false,"{pow-minimum-bits:9}"],"id":"65795770-1647503153","chain_name":"msisthesis001"}

error code: -8
error message:
Invalid custom fields, expecting object

When trying to change parameters, I am getting this error, Kindly suggest what I am missing, I tried the url https://www.multichain.com/developers/upgrading-nodes-chains/ to reach to this point and now stucked. If an example is shared, it would help a lot

Mining stopped on round robin when node revoked and new node granted

Thu, 13 May 2021 10:16:45 +0000

Mining has stopped, after revoking one address and granting another and two of the nodes by accident got new IP. I noticed also that the logs contain a lot of timeout when connecting to IP, that are not listed in peers, and ports seem to be random. I have added nodes and removed nodes by ip.

In a nutshell, all 3 nodes have the same blocks, getpeerinfo shows the same nodes, permissions show the same addresses, but -1 for all sync headers/blocks and the mining wont resume.

Running listpermissions mine * true
This address 1bWg4k.. is *new* and has been granted with mine.
Mining for this address was revoked "1aXHYV..."

All three nodes have the same 3 addresses.

[
    {
        "address" : "1En1g5...",
        "for" : null,
        "type" : "mine",
        "startblock" : 0,
        "endblock" : 4294967295
    },
    {
        "address" : "1Yjcr4...",
        "for" : null,
        "type" : "mine",
        "startblock" : 0,
        "endblock" : 4294967295
    },
    {
        "address" : "1bWg4k...",
        "for" : null,
        "type" : "mine",
        "startblock" : 0,
        "endblock" : 4294967295
    }
]

All nodes have the last 5 blocks.

NOTE: Block 11185 address (miner) has been revoked.

[
    {
        "hash" : "0094e62c5a5625b2498afb12380169f5e6d4139f27358e6dff17a81ca0ebe8b5",
        "miner" : "1Yjcr4...",
        "confirmations" : 5,
        "height" : 11183,
        "time" : 1620402689,
        "txcount" : 8
    },
    {
        "hash" : "00b93e84a241b61f4594fc5c018ed0ca0a1abb356e2ab75a7f03b3efa4b58f16",
        "miner" : "1En1g5...",
        "confirmations" : 4,
        "height" : 11184,
        "time" : 1620402736,
        "txcount" : 1
    },
    {
        "hash" : "00bd0c65b5ae2536e4a949598b50b7f7768d5e493535c796c01ca970ee5b6396",
        "miner" : "1aXHYV...", <- this node has been revoked
        "confirmations" : 3,
        "height" : 11185,
        "time" : 1620406320,
        "txcount" : 2
    },
    {
        "hash" : "0079265b34d729fde68fa6711da1c65e863e234a427d2491dee099c3975eff32",
        "miner" : "1Yjcr4...",
        "confirmations" : 2,
        "height" : 11186,
        "time" : 1620406364,
        "txcount" : 1
    },
    {
        "hash" : "009bc6a7edaf92e49e53bc9c61ceaa603c88dc1f165376be285f05815f4ba606",
        "miner" : "1En1g5...",
        "confirmations" : 1,
        "height" : 11187,
        "time" : 1620755260,
        "txcount" : 2
    }
]

[
    {
        "id" : 6,
        "addr" : "172.31..:5000",
        "addrlocal" : "172.31.5.117:63070",
        "services" : "0000000000000001",
        "lastsend" : 1620899387,
        "lastrecv" : 1620899387,
        "bytessent" : 15965,
        "bytesrecv" : 12112,
        "conntime" : 1620898029,
        "pingtime" : 0.07813200,
        "version" : 70002,
        "subver" : "/MultiChain:0.1.0.9/",
        "handshakelocal" : "1Yjcr4...",
        "handshake" : "1En1g5...",
        "inbound" : false,
        "startingheight" : 11187,
        "banscore" : 0,
        "synced_headers" : 11187,
        "synced_blocks" : 11187,
        "inflight" : [
        ],
        "whitelisted" : false
    },
    {
        "id" : 7,
        "addr" : "54.246..:50136",
        "addrlocal" : "52.215.211.244:5000",
        "services" : "0000000000000001",
        "lastsend" : 1620899389,
        "lastrecv" : 1620899389,
        "bytessent" : 9934,
        "bytesrecv" : 9935,
        "conntime" : 1620898030,
        "pingtime" : 0.06250000,
        "version" : 70002,
        "subver" : "/MultiChain:0.1.0.9/",
        "handshakelocal" : "1Yjcr4...",
        "handshake" : "1En1g5...",
        "inbound" : true,
        "startingheight" : 11187,
        "banscore" : 0,
        "synced_headers" : -1,
        "synced_blocks" : -1,
        "inflight" : [
        ],
        "whitelisted" : false
    },
    {
        "id" : 8,
        "addr" : "34.254..:5000",
        "addrlocal" : "52.215..:63091",
        "services" : "0000000000000001",
        "lastsend" : 1620899391,
        "lastrecv" : 1620899391,
        "bytessent" : 14688,
        "bytesrecv" : 10461,
        "conntime" : 1620898093,
        "pingtime" : 0.09370900,
        "version" : 70002,
        "subver" : "/MultiChain:0.1.0.9/",
        "handshakelocal" : "1Yjcr4...",
        "handshake" : "1bWg4k...",
        "inbound" : false,
        "startingheight" : 11187,
        "banscore" : 0,
        "synced_headers" : -1,
        "synced_blocks" : -1,
        "inflight" : [
        ],
        "whitelisted" : false
    },
    {
        "id" : 9,
        "addr" : "172.31..:62172",
        "addrlocal" : "172.31..:5000",
        "services" : "0000000000000001",
        "lastsend" : 1620899387,
        "lastrecv" : 1620899387,
        "bytessent" : 8924,
        "bytesrecv" : 10048,
        "conntime" : 1620898094,
        "pingtime" : 0.09370900,
        "version" : 70002,
        "subver" : "/MultiChain:0.1.0.9/",
        "handshakelocal" : "1Yjcr4...",
        "handshake" : "1bWg4k...",
        "inbound" : true,
        "startingheight" : 11187,
        "banscore" : 0,
        "synced_headers" : -1,
        "synced_blocks" : -1,
        "inflight" : [
        ],
        "whitelisted" : false
    }
]

"anyone-can-connect" : false,
    "anyone-can-send" : false,
    "anyone-can-receive" : false,
    "anyone-can-receive-empty" : false,
    "anyone-can-create" : false,
    "anyone-can-issue" : false,
    "anyone-can-mine" : false,
    "anyone-can-activate" : false,
    "anyone-can-admin" : false,
    "support-miner-precheck" : true,
    "allow-p2sh-outputs" : true,
    "allow-multisig-outputs" : true,
    "setup-first-blocks" : 60,
    "mining-diversity" : 1.00000000,
    "admin-consensus-upgrade" : 0.50000000,
    "admin-consensus-admin" : 0.25000000,
    "admin-consensus-activate" : 0.25000000,
    "admin-consensus-mine" : 0.50000000,
    "admin-consensus-create" : 0.00000000,
    "admin-consensus-issue" : 0.00000000,
    "lock-admin-mine-rounds" : 10,
    "mining-requires-peers" : true,
    "mine-empty-rounds" : 0.20000000,

Probability of a fork with round-robin consesus

Fri, 16 Feb 2018 08:25:51 +0000

Lets say we have a blockchain with 5 nodes, all running on the exact same configs, and mining-diversity is set to 0.5

Now during the first round of mining. any of the 5 nodes can mine the next block. Since there is no PoW, won't all the 5 nodes have an equal chance of creating a block at the same time? (as all params and system config is identical).

Even for subsequent rounds, when more than 1 node is eligible to create the next block, what stops them from creating a block at the exact same time?

Or is there some negligible amount of work involved which creates the difference? And if yes, to what extent? Are internal adjustments made to this if forks keep occuring?

Round Robin Weaknesses

Wed, 14 Feb 2018 09:58:43 +0000

I have a Blockchain set up with 3 nodes. Everyone has mining permissions.

As I understand it right, the round robin selects one of the three nodes with permission to validate a new block.

So the selected node has full power of defining what is valid and what is not, right?

What if the selected node tries to fraud the system? The other nodes won't check in addition for validation, right?

round-robin and pow

Wed, 07 Jun 2017 01:41:45 +0000

Acorrding to the Multichain White Paper, the private blockchain uses a round-robin schedule and a mining diversity threshold, instead of the proof of work.

We have some questions:

1) If we create a bitcoin-style blockchain, in which "chain-protocol = bitcoin; anyone-can-connect = true; anyone-can-mine = true...". Should we still use the round-robin schedule? Is it safer or more effective than PoW?

2) In the round-robin schedule, What are the basic objects of scheduling? the IP address of the node server or the wallet addresses of the node server?
If it is the later, a node server have created many,many wallet addresses of mine -permission, whether will it have more mine right and rate than other nodes?