MultiChain Developer Q&A - Recent questions tagged max-std-op-return-size

uploading and retrieval of file from MC2.0 Alpha 3

Thu, 28 Jun 2018 19:02:47 +0000

Hi we are using multichain 2.0 alpha 3 version, as explained three parameters have been changed, we are able to crunch file upto 2 MB now, but while verifying/ retriving the file from streams, the values turn to be NULL, Pl help where are we wrong

in am not been able to find maxshowndata & gettxoutdata

{
"chain-protocol" : "multichain",
"chain-description" : "MultiChain chain1",
"root-stream-name" : "root",
"root-stream-open" : true,
"chain-is-testnet" : false,
"target-block-time" : 15,
"maximum-block-size" : 20097500,
"maximum-chunk-size" : 1048576,
"maximum-chunk-count" : 1024,
"default-network-port" : 9731,
"default-rpc-port" : 9730,
"anyone-can-connect" : false,
"anyone-can-send" : false,
"anyone-can-receive" : false,
"anyone-can-receive-empty" : true,
"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-arbitrary-outputs" : false,
"allow-p2sh-outputs" : true,
"allow-multisig-outputs" : true,
"setup-first-blocks" : 60,
"mining-diversity" : 0.300000000001,
"admin-consensus-upgrade" : 0.500000000001,
"admin-consensus-admin" : 0.500000000001,
"admin-consensus-activate" : 0.500000000001,
"admin-consensus-mine" : 0.500000000001,
"admin-consensus-create" : 1e-12,
"admin-consensus-issue" : 1e-12,
"lock-admin-mine-rounds" : 10,
"mining-requires-peers" : true,
"mine-empty-rounds" : 10.000000000001,
"mining-turnover" : 0.500000000001,
"first-block-reward" : -1,
"initial-block-reward" : 0,
"reward-halving-interval" : 52560000,
"reward-spendable-delay" : 1,
"minimum-per-output" : 0,
"maximum-per-output" : 100000000000000,
"minimum-offchain-fee" : 0,
"minimum-relay-fee" : 0,
"native-currency-multiple" : 100000000,
"skip-pow-check" : false,
"pow-minimum-bits" : 8,
"target-adjust-freq" : -1,
"allow-min-difficulty-blocks" : false,
"only-accept-std-txs" : true,
"max-std-tx-size" : 20097500,
"max-std-op-returns-count" : 32,
"max-std-op-return-size" : 20097152,
"max-std-op-drops-count" : 5,
"max-std-element-size" : 40000,
"chain-name" : "chain1",
"protocol-version" : 20003,
"network-message-start" : "f8e4f7ed",
"address-pubkeyhash-version" : "00a3a284",
"address-scripthash-version" : "0580bcad",
"private-key-version" : "801d6d29",
"address-checksum-value" : "c8835e5c",
"genesis-pubkey" : "034475839d78341a573659ab10ea846b568dacd5a3de19f379fb8c8855ded0170f",
"genesis-version" : 1,
"genesis-timestamp" : 1530198132,
"genesis-nbits" : 536936447,

Standard Transaction Defenitions in params file

Mon, 06 Feb 2017 18:12:08 +0000

What should be the max-std-tx-size if OP_RETURN count = 10 and OP_RETURN size = 8MB?
(I have set max block size to 32 MB, should I decrease OP_RETURN count if max block size is 32MB? )

following are the entries in the params file:

# Standard transaction definitions

only-accept-std-txs = true              # Only accept and relay transactions which qualify as 'standard'.
max-std-tx-size = 4194304               # Maximum size of standard transactions, in bytes. (1024 - 10000000)
max-std-op-returns-count = 10           # Maximum number of OP_RETURN metadata outputs in standard transactions. (0 - 1024)
max-std-op-return-size = 8388608        # Maximum size of OP_RETURN metadata in standard transactions, in bytes. (0 - 8388608)
max-std-op-drops-count = 5              # Maximum number of OP_DROPs per output in standard transactions. (0 - 100)
max-std-element-size = 600              # Maximum size of data elements in standard transactions, in bytes. (128 - 32768)

Can we change the "target-block-time" to a new value ?

Mon, 18 Apr 2016 12:25:55 +0000

Can we change the "target-block-time" parameter in the params.dat of an existing chain? I understand that if thats possible it needs to be synced across all the nodes in the chain, which might be a challenge.
but do we have a facility if in case we want to change any of the parameter. Another possible candidate is the "max-std-op-return-size". I was testing with private chains and the requirement of modifying the op-return-size appeared later and I had to clone the chain and modify the paramater.

However , I wanted to check if the reload of configuration is supported.

I tried modifying the params.dat after shutting down the node, but multichaind threw the following error message:

ERROR: Parameter set for blockchain <chain> is invalid.