Monitoring a Node: LiveView Mode

The node can be launched both in Simple mode and LiveView mode. When the node is launched in LiveView mode, the user sees node’s TUI (Textual User Interface) right in the terminal.

Please note that LiveView mode can be activated on Unix systems only; it does not work on Windows.

Node Configuration

To activate LiveView mode, please open node’s configuration file and find an option ViewMode. Set it to LiveView:

ViewMode: LiveView

After starting, you will see the TUI:

TUI

Exit

To stop the node running in LiveView mode, press Q (or q) key. It is possible to stop it using Ctrl+C keys as well.

Color Theme

It is possible to change the color theme of the TUI.

Press L (or l) to set the light theme:

TUI Light

Press D (or d) to set the dark theme (the default one).

Top Line

The top line of TUI contains two important fields:

  1. release corresponds to the protocol node uses. For example, Byron corresponds to RealPBFT.

  2. Port shows the local port of this node. This port is taken from the topology the node is running with.

Node Info

The right column of the TUI displays basic node info:

  • version - node’s full version (the same version as from cardano-node --version command).

  • commit - commit node was built from.

  • platform - the platform node runs on (Linux, Windows, or Darwin).

  • uptime - the time how long the node is running.

Blockchain Info

The right column of the TUI displays blockchain info:

  • epoch / slot - epoch shows the number of current epoch, slot shows the number of the current slot in this epoch.

  • block number - the number of the last block in the existing blockchain.

  • chain density - blockchain density, in percent.

Forge Info

The right column of the TUI displays forge info:

  • blocks minted - the number of blocks minted by this node.

  • slots lead - the number of slots when this node was a leader.

  • slots missed - the number of slots this node missed as a leader (so block wasn’t minted).

  • cannot lead - the number of cases when this node could not mint a block (for example, because of the invalid key).

Transactions Info

The right column of the TUI displays transactions info:

  • TXs processed - the number of processed transactions. Technically it is the number of transactions that are already removed from the mempool, so we can treat them as completely processed.

Peers Info

The right column of the TUI displays peers info:

  • peers - the number of connected peers.

And if you press P (or p) key, you will see another TUI window with the list of connected peers. This list contains information about every peer:

  • Address - peer’s endpoint (IP-address and port).

  • Status - peer’s status (shutdown, aberrant, fetching or ready).

  • Slot - The maximum slot of a block that has ever been in flight for this peer.

  • In flight: Reqs - the number of block fetch requests that are currently in-flight.

  • In flight: Blocks - the points for the set of blocks currently in-flight.

  • In flight: Bytes - the sum of the byte count of blocks expected from all in-flight fetch requests.

To return to the main TUI window, please press Esc key.

Mempool Info

There are two progress bars that display mempool-related info:

  • Mempool (Bytes) - real mempool’s capacity, in bytes.

  • Mempool (Txs) - calculated mempool’s capacity, in transactions.

Please note that the number on Mempool (Txs) progress bar shows the number of transactions that currently are in the mempool. After these transactions will be processed, this number will be set to 0 again.

Resources Info

There are progress bars that display resources used by node’s process:

  • Memory usage - memory used, in MB.

  • CPU usage - CPU usage, in percents.

  • Disk R - read-operations’ rate on the hard drive, in KB/s.

  • Disk W - write-operations’ rate on the hard drive, in KB/s.

  • Network In - input-operations’ rate on the network, in KB/s.

  • Network Out - output-operations’ rate on the network, in KB/s.

Please note that the value at the right corner of the progress bar shows the maximum rate being measured.