During some investigation on another issue we were testing the current master branch (22646d953d8106e567b1da9aab98b627a2fb204f) with some of our loadtests and we receive panics from here:
https://github.com/mongodb/mongo-go-driver/blob/master/x/mongo/driver/topology/pool.go#L416
{"app":"matchmaking-api","env":"test","error":"connection() : auth error: sasl conversation error: unable to authenticate using mechanism \"SCRAM-SHA-1\": context canceled","game":"","message":"could not return all matchmakings for filter [map[game:pubg region:EU] map[game:csgo region:EU]]","severity":"ERROR","showAllGames":false,"timestamp":{"seconds":1567596173,"nanos":165825408},"userID":"admin","version":"SNAPSHOT"}{"app":"matchmaking-api","env":"test","error":"connection() : auth error: sasl conversation error: unable to authenticate using mechanism \"SCRAM-SHA-1\": context canceled","game":"","message":"could not return all matchmakings for filter [map[game:pubg region:EU] map[game:csgo region:EU]]","severity":"ERROR","showAllGames":false,"timestamp":{"seconds":1567596173,"nanos":165825408},"userID":"admin","version":"SNAPSHOT"}panic: runtime error: invalid memory address or nil pointer dereference[signal SIGSEGV: segmentation violation code=0x1 addr=0x18 pc=0xb4b970] goroutine 2848 [running]:go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*pool).closeConnection(0xc0000c5080, 0xc0008fd600, 0x0, 0x0) /home/bwilsonhunt/go/pkg/mod/go.mongodb.org/mongo-driver@v1.1.1-0.20190903130008-22646d953d81/x/mongo/driver/topology/pool.go:416 +0xb0go.mongodb.org/mongo-driver/x/mongo/driver/topology.connectionCloseFunc.func1(0xc0008fd600) /home/bwilsonhunt/go/pkg/mod/go.mongodb.org/mongo-driver@v1.1.1-0.20190903130008-22646d953d81/x/mongo/driver/topology/pool.go:119 +0x37created by go.mongodb.org/mongo-driver/x/mongo/driver/topology.connectionCloseFunc /home/bwilsonhunt/go/pkg/mod/go.mongodb.org/mongo-driver@v1.1.1-0.20190903130008-22646d953d81/x/mongo/driver/topology/pool.go:119 +0x61
It happens consistently accross all the pods.
This is the mongo connection string used:
```
mongodb://xx:xxxx@xxx:27017,xxx:27017,xxxx:27017/matchmaking-service?ssl=true&authSource=admin&maxPoolSize=100&minPoolSize=10
```
- is depended on by
-
GODRIVER-1297 Opening new connections takes a long time
- Closed