Debugging

CometBFT debug kill

CometBFT comes with a debug sub-command that allows you to kill a live CometBFT process while collecting useful information in a compressed archive. The information includes the configuration used, consensus state, network state, the node’ status, the WAL, and even the stack trace of the process before exit. These files can be useful to examine when debugging a faulty CometBFT process.

cometbft debug kill <pid> </path/to/out.zip> --home=</path/to/app.d>

will write debug info into a compressed archive. The archive will contain the following:

├── config.toml
├── consensus_state.json
├── net_info.json
├── stacktrace.out
├── status.json
└── wal

Under the hood, debug kill fetches info from /status, /net_info, and /dump_consensus_state HTTP endpoints, and kills the process with -6, which catches the go-routine dump.

CometBFT debug dump

Also, the debug dump sub-command allows you to dump debugging data into compressed archives at a regular interval. These archives contain the goroutine and heap profiles in addition to the consensus state, network info, node status, and even the WAL.

cometbft debug dump </path/to/out> --home=</path/to/app.d>

will perform similarly to kill except it only polls the node and dumps debugging data every frequency seconds to a compressed archive under a given destination directory. Each archive will contain:

├── consensus_state.json
├── goroutine.out
├── heap.out
├── net_info.json
├── status.json
└── wal

Note: goroutine.out and heap.out will only be written if a profile address is provided and is operational. This command is blocking and will log any error.