Node Configuration

Apart from a few options like block time, epoch length, and slot length which are provided through Yaci CLI, other devnet node-related configurations can be configured through the node.properties file. The configurations defined in the node.properties file will be used during devnet node creation.

For zip based installation, this file is located under installation directory config/node.properties.

For curl based installation, this file is located under $HOME/.yaci-devkit/config/node.properties.

Please refer to the config/node.properties file for all the node specific configurations.

Example of few key configurations:

nodeMode

nodeMode controls how DevKit starts the local network.

nodeMode=companion

Supported Yano-backed modes:

• companion: Yano bootstraps the network, then hands over to the Haskell node. This is the default mode.
• yano-only: Yano runs as the only node, and Yaci Store syncs directly from Yano.

See Node Modes for details about when to use each mode.

securityParam

To set the security parameter for the node. Default value is 300. (300 blocks)

To change the configuration, add to the node.properties file

securityParam=<int value>

Note: If you want to stop your node for some time and restart it later without a reset, allowing it to continue from where it left off and use existing data, you may want to set securityParam to a higher value. Otherwise, the node may get stuck and you need to reset the node.

Let's say you want to stop your node and start the node again next day to continue from where it left off, then you can set securityParam to a higher values like 86400 for 1 sec block time.

maxKESEvolutions and slotsPerKESPeriod

Defaults are 62 and 10000000. The node derives the current KES period as slot / slotsPerKESPeriod, and an operational certificate expires once the periods elapsed since it was issued exceed maxKESEvolutions.

In companion mode the bootstrap shifts genesis back by whole epochs and then catches up to wall clock, so the chain starts at a high slot number. At the mainnet slotsPerKESPeriod of 129600 that shift alone consumes a large share of the evolutions before the devnet produces its first real block, and the share grows with epoch length. The large period keeps a devnet inside KES period 0 for its whole life.

The trade-off is that a DevKit devnet does not exercise KES rotation. Set both to mainnet-like values (62 and 129600) if that is what you want to test:

maxKESEvolutions=62
slotsPerKESPeriod=129600

stabilityWindowFactor

When securityParam is left at 0, DevKit derives it from the epoch length so that the stability window (3k/f slots) covers this fraction of the epoch:

securityParam = epochLength * activeSlotsCoeff * stabilityWindowFactor / 3

The default is 0.5, half an epoch. The Haskell block producer can only check leadership for slots within 3k/f of its chain tip, so a gap in block production longer than that (the host asleep, the container stopped) freezes the chain until it is reset. This factor times the epoch's wall-clock length is therefore the devnet's idle tolerance. Raising it buys tolerance without a longer epoch:

stabilityWindowFactor=0.7

Values up to about 0.7 are sound: 4k/f must stay below the epoch length for the epoch nonce schedule, and the rewards calculation needs the stability window inside the epoch. Setting securityParam explicitly bypasses this derivation.

traceChainSyncClient

Whether the node logs its chain-sync client (TraceChainSyncClient). Default false. Set to true to see why a node rejects a bootstrap chain during a Yano handover. It logs every header received from a peer, so expect a busier log on multi-node devnets.

peerSharing

To enable or disable peer sharing. Default value is true.

Note: More configurations can be found in node.properties file.