dont-use-fsync real world impact

[Simon Hobson]

Bob Harold <rharolde at umich.edu> wrote:

> If you have a failover pair, then changes to one server get sent to the other server, and I expect that to be immediate (but don't know that for sure), so if one server fails, you would only lose a few seconds or less.  In that case would running without fsync be reasonable?

AIUI failover updates are "instant" but there's a config option to batch them. Similarly IIRC there's now a config option to batch lease file updates/fsyncs ? Both these config options being there to allow adjustment of the performance/security tradeoff.

But you do raise a good point, with failover you have a near instantly updated backup of the leases. Apart from the obvious, there have been some interesting suggestions in the past for how that could be used.