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

Question

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.

Answer 1

I'm afraid it's not possible to change a blockchain's configuration after it has been set in motion.

Answer 2

you cant do this at the moment. i dont know if they plan to implement an addon to enable this, but in MC19 it is not possible. i was testing various values of "target-block-time" to see how it affects performance on my chain and i had to make a new one and load a bunch of assets into it every time i try a new value.

it would be awesome to be able to edit the parameters live or at least shut down all nodes and edit params and restart them but right now to do this you have to run the CLONE command.

Answer 3

Once the genesis block is created using the params.dat file, it is locked and cannot be modified. There are few params which can be modified in the local node defined as run time paramters as defined in (http://www.multichain.com/developers/runtime-parameters/) using the console command, however the "target-block-time" cannot be changed as this is locked in the genesis block creation process and all the other nodes follow the defined params. I think the only way is to create a new chain and define the preferred param values. Also if "target-block-time" is allowed to be changed, it could create security issues wherein a node would make an attempt to reduce this time and add blocks in an undesired manner. I think this is one of the important parameter needed be examined and configured based on the environment where the chain is going to be setup.