We use the Ping method to check periodically if the service is available, and if not, to try and auto-connect in case it is a temporary connection issue.
I am encountering an issue on closing a running server where a call to an in-progress Ping fails with a panic: Session already closed rather than an expected error return.
What version of MongoDB are you using (mongod --version)?
db version v3.6.11
git version: b4339db12bf57ffee5b84a95c6919dbd35fe31c9
OpenSSL version: OpenSSL 1.0.2o-fips 27 Mar 2018
allocator: tcmalloc
modules: none
build environment:
distmod: 2008plus-ssl
distarch: x86_64
target_arch: x86_64
What version of Go are you using (go version)?
go version go1.11.9 windows/amd64
What operating system and processor architecture are you using (go env)?
set GOARCH=amd64
set GOBIN=D:\Development\Go\bin
set GOCACHE=C:\Users\XXXXX\AppData\Local\go-build
set GOEXE=.exe
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOOS=windows
set GOPATH=D:\Development\work\go
set GOPROXY=
set GORACE=
set GOROOT=D:\Development\Go
set GOTMPDIR=
set GOTOOLDIR=D:\Development\Go\pkg\tool\windows_amd64
set GCCGO=gccgo
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=C:\Users\XXXXX\AppData\Local\Temp\go-build398815790=/tmp/go-build -gno-record-gcc-switches
What did you do?
// Create the session and Dial Mongo
var mgoSession *mgo.Session
configDBOnce.Do(func() {
// Dial Mongo - get session
mgoSession, err = mgo.Dial(dbHost)
if err != nil {
return
}
// Check session is alive
err = mgoSession.Ping()
if err != nil {
return
}
// Make sure session alive by pinging MongoDB every second and refreshing session if needed
KeepAlive(dbName, mgoSession)
ConfigDB = &MongoDB{mgoSession.DB(dbName)}
})
// KeepAlive pings MongoDB every interval and refreshes session if needed
func KeepAlive(dbName string, mgoSession *mgo.Session) {
go func() {
for {
time.Sleep(time.Second * 5)
if err := mgoSession.Ping(); err != nil {
log.Print(fmt.Sprintf("Lost Mongo connection to %s: %s. Restoring...", dbName, err))
mgoSession.Refresh()
}
}
}()
}
When sending a terminate to the server, the following panic is thrown rather than the err being returned from .Ping() to be handled gracefully.
We use the Ping method to check periodically if the service is available, and if not, to try and auto-connect in case it is a temporary connection issue.
I am encountering an issue on closing a running server where a call to an in-progress Ping fails with a panic: Session already closed rather than an expected error return.
What version of MongoDB are you using (
mongod --version)?What version of Go are you using (
go version)?What operating system and processor architecture are you using (
go env)?What did you do?
When sending a terminate to the server, the following panic is thrown rather than the err being returned from .Ping() to be handled gracefully.