tree 1276ce08dd648b170aedad27191f9b9bd8a2aafb
parent 6c4815c02fc9f69fb4862e299603c58c9155612a
author Hengfeng Li <hengfeng@google.com> 1587018892 +1000
committer Hengfeng Li <hengfeng@google.com> 1587104977 +0000

spanner: fix incorrect decreasing metrics

This issue happens when the number of sessions is downsizing to a
smaller value during a health recyling period (10 mins). When the
session pool does not need this many sessions, the health maintainer
will adjust the number of sessions to a lower number.

The current implementation to decrease numReads and numWrites is
incorrect because `p.idleList.Remove` and `p.idleWriteList.Remove`
always return a non-nil value. This leads to a decrease for both
metrics at the same time.

Change-Id: Ie21c30200559ebbe95ec09c65e7e54040fcf0cfc
Reviewed-on: https://code-review.googlesource.com/c/gocloud/+/54830
Reviewed-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Knut Olav Løite <koloite@gmail.com>