Configuration

The PN configuration is to create a data directory and set up several values in the configuration file kpnd.conf.

1. Create a PN Data Directory

2. Install node key

3. Install static-node.json

4. Configure the PN with kpnd.conf.

PN Data Directory Creation

Considering the fact that the size of Klaytn blockchain data is always increased, it is recommended to use a big enough storage. You may need to create the directory on your desired path.

$ mkdir -p /var/kpnd/data

Install Node Key

In order to operate a PN, a nodekey is required. The KPN binary will create a new one for you if you do not have it. If you have one, you need to put your nodekey into the PN data directory. The way to create a nodekey is in the "Before You Install" section. The following command line copies the nodekey into the PN data directory.

$ cp nodekey /var/kpnd/data

Install static-nodes.json

The static-nodes.json should be created from the PN operator. It contains the addresses that your PN is connected to. It is recommended to add the addresses including your CN and a PN from another Core Cell. Please contact to the Klaytn official email for more details ([e-mail] for Cypress or [e-mail] for Baobab).

static-nodes.json

[
  "kni://4f2f47f3bf35a2c576d3345e6e9c49b147d510c05832d2458709f63c3c90c76ead205975d944ed65e77dd4c6f63ebe1ef21d60da95952bc1e200e7487f4d9e1b@10.11.2.101:32323?discport=0&ntype=cn",
  "kni://8dee912aeda2ccfaa4fe421f015d4d75c2e3fd4aab75fa399b42767caad33531e57f3356b4a4af374593e33ec4320e1325aa2390a7be2489fa6b5724894680eb@10.11.2.102:32323?discport=0&ntype=pn"
]

The node URI of the PN is in the "Before You Install" section. (Note: This IP address is different from CN public IP.) The following command line copies the static-nodes.json file into the PN data directory.

$ cp static-nodes.json /var/kpnd/data

Update the Configuration File

Configuration File Location:

• For the archive distribution, the config directory location defaults to $INSTALL_PATH/kpn-linux-amd64/conf/.

• For the package distribution, the config directory defaults to /etc/kpnd/conf/.

Add Data Directory

You should update the the data directory environment variable $DATA_DIR on the configuration file kpnd.conf.

...
DATA_DIR=/var/kpnd/data
...

Fast Sync (Optional)

Each PN maintains a copy of the network's chain data. If a node is out of sync, it can obtain this data from other nodes in the network -- a process known as syncing. When a new PN is first started, it must download the entire chain data from the network.

To accelerate this process, you may perform a fast sync by downloading a snapshot of the chain data before starting the PN. This can dramatically reduce the time the PN will spend syncing on first start.

Download the latest chaindata snapshot from the Cypress snapshot archive or Baobab snapshot archive. Before starting kpnd, extract the snapshot inside the DATA_DIR you configured in kpnd.conf.

For example:

$ tar -C /var/kpnd/data -xvf klaytn-cypress-chaindata-latest.tar.gz

Or,

$ tar -C /var/kpnd/data -xvf klaytn-baobab-chaindata-latest.tar.gz

After the data is extracted, you may start the PN normally.