To summarize, edit logs are replicated, but it happens via interaction with a separate set of daemons called the journal nodes. The active persists its edit logs to a majority of journal nodes (deployed in multiple). The standby reads the edits from the journal nodes and applies them locally.
The separate journal nodes provide redundancy, so that edits don't need to be blocked if a single node dies. By continuously reading the edits, the standby can stay up to date with changes applied at the active and failover quickly if needed.
On Sat, Nov 9, 2013 at 7:29 PM, origin <[EMAIL PROTECTED]> wrote:
> Hey guys: > I was curious that why Active NameNode do not repilcation edits log to > Standby NameNode like MySQL dose?
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