Currently the discovery url is just one endpoint. But actually it
should be the same as the etcdctl, which means that it should be
a list of endpoints. When one endpoint is down, the clientv3 can
fail over to the next endpoint automatically.
To avoid inconsistant behavior during cluster upgrade we are feature
gating persistance behind cluster version. This should ensure that
all cluster members are upgraded to v3.6 before changing behavior.
To allow backporting this fix to v3.5 we are also introducing flag
--experimental-enable-lease-checkpoint-persist that will allow for
smooth upgrade in v3.5 clusters with this feature enabled.
When a unary request takes more than predefined duration, this request
is defined as "expensive" and a warning is printed. The expensive request
duration is hard-coded to 300 ms. It can be not enough for example
for transactions with a lot of operations. The warnings just blow up
the log files and reduce throughput.
This fix allows user to configure the "expensive" request duration.
Signed-off-by: Alexey Roytman <roytman@il.ibm.com>
Motivation:
- ServerConfig is part of 'embed' public API, while etcdserver is more 'internal'
- EtcdServer is already too big and config is pretty wide-spread leaf
if we were to split etcdserver (e.g. into pre & post-apply part).
