How do I change the validator configuration?

An example configuration file is at sawtooth-core/validator/etc/txnvalidator.js.example. Copy that file to a new file in the same directory and make changes to the new file. When starting the txnvalidator, use the –config argument to reference the configuration file, In this example, we have copied the txnvalidator.js.example file to single- node.js and modified it:

$ cd /project/sawtooth-core
$ ./bin/txnvalidator -v --config validator/etc/single-node.js

Multiple config files can be overlaid, and all of the settings in the config file can be overridden on the command line, but that’s beyond the scope of this answer.

What configuration changes should I make to run a single validator?

Copy the file sawtooth-core/validator/etc/txnvalidator.js.example to single-node.js and make the following changes:

TargetWaitTime The desired mean inter-block commit time across the network. While the default is 30 seconds, we recommend 5 seconds for development and experimenting.

InitialWaitTime This is only important when starting the first node which will initialize the ledger (i.e. GenesisLedger is true). This will often be the case when testing. We recommend setting it to the same value as TargetWaitTime.