f one node is slow, all the operation PerformMultiGet is slow
That kind of make sense; total time is the worst time plus the rest. You may get better performance by skipping the bulk methods in this case and using TPL if it will work for you. Checkout this post for example: Couchbase performance (misconfiguration or something else?) - #8 by jmorris
This slowdown may coming from other bottleneck (connection …). In my
subject, when it occured, i can see an increase of number connection
That is a big increase in connections. The client does have a connection pool that will grow to a max size, but that seems excessive.
-Jeff