The idea is that all peers eventually have the same collection of log entries, with an agreed-upon sort method. Currently that sort method is time stamps.
When it’s time to have identical replicas, a log entry must be appended that says the log is closed. Once all peers have this, the log is now immutable and can be treated as such. An example of this (for a payroll system) is a collection of entries for time clock in and outs, payroll taxes withheld, direct deposits to employees, etc when it’s time to do a payroll. The log is closed and that data can never be altered, but now the data can be relied on by someone else.
Conceptually this is surprisingly similar to the type of internal logs a typical database like PostgreSQL keeps.
When it’s time to have identical replicas, a log entry must be appended that says the log is closed. Once all peers have this, the log is now immutable and can be treated as such. An example of this (for a payroll system) is a collection of entries for time clock in and outs, payroll taxes withheld, direct deposits to employees, etc when it’s time to do a payroll. The log is closed and that data can never be altered, but now the data can be relied on by someone else.
Conceptually this is surprisingly similar to the type of internal logs a typical database like PostgreSQL keeps.