params.dat - What parameters can I change freely after creating a blockchain?

Question

Hello,

I have a question.

We have a file parms.dat:

~/.multichain/myblockchain/params.dat

What parameters can I change in this file freely after creating a blockchain?

Are there any parameters that I can not absolutely change after creating a blockchain?

I understand that they probably belong to those about the genesis block section. But some other? Will I find out some information about this?

Answer 1

In MultiChain 1.x in general you cannot change any parameter, once the chain has started. We're working on making this much more flexible for 2.x, now in development. MultiChain 1.0.1 provides the beginnings of this functionality, letting you change the blockchain protocol version only.

Comments

So now what parameters can be changed in 2.x?

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The list is documented in the "help create" message, where upgrades are described. It is also in the documentation for the create API (where type=upgrade) on this page: https://www.multichain.com/developers/json-rpc-api/

Here is the list reproduced:

protocol-version
target-block-time
maximum-block-size
maximum-chunk-size
maximum-chunk-count
all max-std-*
all anyone-can-* except mine and admin

To prevent abrupt changes in blockchain capacity and performance, target-block-time cannot be changed more than once per 100 blocks and all capacity-related parameters cannot be changed to less than half or more than double their previous size.