Running in production ===================== Logging ------- Default logging level (``main:info,state:info,*:``) should suffice for normal operation mode. Read `this post __` for details on how to configure ``log_level`` config variable. Some of the modules can be found `here <./how-to-read-logs.html#list-of-modules>__`. If you're trying to debug Tendermint or asked to provide logs with debug logging level, you can do so by running tendermint with ``--log_level="*:debug"``. Consensus WAL ------------- Consensus module writes every message to the WAL (write-ahead log). It also issues fsync syscall through `File#Sync __` for messages signed by this node (to prevent double signing). Under the hood, it uses `autofile.Group __`, which rotates files when those get too big (> 10MB). The total maximum size is 1GB. We only need the latest block and the block before it, but if the former is dragging on across many rounds, we want all those rounds. Replay ~~~~~~ Consensus module will replay all the messages of the last height written to WAL before a crash (if such occurs). The private validator may try to sign messages during replay because it runs somewhat autonomously and does not know about replay process. For example, if we got all the way to precommit in the WAL and then crash, after we replay the proposal message, the private validator will try to sign a prevote. But it will fail. That's ok because we’ll see the prevote later in the WAL. Then it will go to precommit, and that time it will work because the private validator contains the ``LastSignBytes`` and then we’ll replay the precommit from the WAL. Make sure to read about `WAL corruption <./specification/corruption.html#wal-corruption>__` and recovery strategies.