construct/doc/TROUBLESHOOTING.md

TROUBLESHOOTING

Recovering from broken configurations

If your server ever fails to start from an errant conf item: you can override any item using an environmental variable before starting the program. To do this simply replace the '.' characters with '_' in the name of the item when setting it in the environment. The name is otherwise the same, including its lower case.

Recovering from database corruption

In very rare cases after a hard crash the journal cannot completely restore data before the crash. Due to the design of rocksdb and the way we apply it for Matrix, data is lost in chronological order starting from the most recent transaction (matrix event). The database is consistent for all events up until the first corrupt event, called the point-in-time.

When any loss has occurred the daemon will fail to start normally. To enable point-in-time recovery use the command-line option -pitrecdb at the next invocation.