func (s *S) TestPrimaryShutdownOnAuthShard(c *C) { if *fast { c.Skip("-fast") } // Dial the shard. session, err := mgo.Dial("localhost:40203") c.Assert(err, IsNil) defer session.Close() // Login and insert something to make it more realistic. session.DB("admin").Login("root", "rapadura") coll := session.DB("mydb").C("mycoll") err = coll.Insert(bson.M{"n": 1}) c.Assert(err, IsNil) // Dial the replica set to figure the master out. rs, err := mgo.Dial("root:rapadura@localhost:40031") c.Assert(err, IsNil) defer rs.Close() // With strong consistency, this will open a socket to the master. result := &struct{ Host string }{} err = rs.Run("serverStatus", result) c.Assert(err, IsNil) // Kill the master. host := result.Host s.Stop(host) // This must fail, since the connection was broken. err = rs.Run("serverStatus", result) c.Assert(err, Equals, io.EOF) // This won't work because the master just died. err = coll.Insert(bson.M{"n": 2}) c.Assert(err, NotNil) // Refresh session and wait for re-election. session.Refresh() for i := 0; i < 60; i++ { err = coll.Insert(bson.M{"n": 3}) if err == nil { break } c.Logf("Waiting for replica set to elect a new master. Last error: %v", err) time.Sleep(500 * time.Millisecond) } c.Assert(err, IsNil) count, err := coll.Count() c.Assert(count > 1, Equals, true) }
func (s *S) TestTopologySyncWithSlaveSeed(c *C) { // That's supposed to be a slave. Must run discovery // and find out master to insert successfully. session, err := mgo.Dial("localhost:40012") c.Assert(err, IsNil) defer session.Close() coll := session.DB("mydb").C("mycoll") coll.Insert(M{"a": 1, "b": 2}) result := struct{ Ok bool }{} err = session.Run("getLastError", &result) c.Assert(err, IsNil) c.Assert(result.Ok, Equals, true) // One connection to each during discovery. Master // socket recycled for insert. stats := mgo.GetStats() c.Assert(stats.MasterConns, Equals, 1) c.Assert(stats.SlaveConns, Equals, 2) // Only one socket reference alive, in the master socket owned // by the above session. c.Assert(stats.SocketsInUse, Equals, 1) // Refresh it, and it must be gone. session.Refresh() stats = mgo.GetStats() c.Assert(stats.SocketsInUse, Equals, 0) }
func (s *S) TestSetModeMonotonicAfterStrong(c *C) { // Test that a strong session shifting to a monotonic // one preserves the socket untouched. session, err := mgo.Dial("localhost:40012") c.Assert(err, IsNil) defer session.Close() // Insert something to force a connection to the master. coll := session.DB("mydb").C("mycoll") err = coll.Insert(M{"a": 1}) c.Assert(err, IsNil) session.SetMode(mgo.Monotonic, false) // Wait since the sync also uses sockets. for len(session.LiveServers()) != 3 { c.Log("Waiting for cluster sync to finish...") time.Sleep(5e8) } // Master socket should still be reserved. stats := mgo.GetStats() c.Assert(stats.SocketsInUse, Equals, 1) // Confirm it's the master even though it's Monotonic by now. result := M{} cmd := session.DB("admin").C("$cmd") err = cmd.Find(M{"ismaster": 1}).One(&result) c.Assert(err, IsNil) c.Assert(result["ismaster"], Equals, true) }
func (s *S) TestDirectToUnknownStateMember(c *C) { session, err := mgo.Dial("localhost:40041?connect=direct") c.Assert(err, IsNil) defer session.Close() session.SetMode(mgo.Monotonic, true) result := &struct{ Host string }{} err = session.Run("serverStatus", result) c.Assert(err, IsNil) c.Assert(strings.HasSuffix(result.Host, ":40041"), Equals, true) // We've got no master, so it'll timeout. session.SetSyncTimeout(5e8 * time.Nanosecond) coll := session.DB("mydb").C("mycoll") err = coll.Insert(M{"test": 1}) c.Assert(err, ErrorMatches, "no reachable servers") // Slave is still reachable. result.Host = "" err = session.Run("serverStatus", result) c.Assert(err, IsNil) c.Assert(strings.HasSuffix(result.Host, ":40041"), Equals, true) }
func (s *S) TestSelectServers(c *C) { if !s.versionAtLeast(2, 2) { c.Skip("read preferences introduced in 2.2") } session, err := mgo.Dial("localhost:40011") c.Assert(err, IsNil) defer session.Close() session.SetMode(mgo.Eventual, true) var result struct{ Host string } session.Refresh() session.SelectServers(bson.D{{"rs1", "b"}}) err = session.Run("serverStatus", &result) c.Assert(err, IsNil) c.Assert(hostPort(result.Host), Equals, "40012") session.Refresh() session.SelectServers(bson.D{{"rs1", "c"}}) err = session.Run("serverStatus", &result) c.Assert(err, IsNil) c.Assert(hostPort(result.Host), Equals, "40013") }
func (s *S) TestDirect(c *C) { session, err := mgo.Dial("localhost:40012?connect=direct") c.Assert(err, IsNil) defer session.Close() // We know that server is a slave. session.SetMode(mgo.Monotonic, true) result := &struct{ Host string }{} err = session.Run("serverStatus", result) c.Assert(err, IsNil) c.Assert(strings.HasSuffix(result.Host, ":40012"), Equals, true) stats := mgo.GetStats() c.Assert(stats.SocketsAlive, Equals, 1) c.Assert(stats.SocketsInUse, Equals, 1) c.Assert(stats.SocketRefs, Equals, 1) // We've got no master, so it'll timeout. session.SetSyncTimeout(5e8 * time.Nanosecond) coll := session.DB("mydb").C("mycoll") err = coll.Insert(M{"test": 1}) c.Assert(err, ErrorMatches, "no reachable servers") // Slave is still reachable. result.Host = "" err = session.Run("serverStatus", result) c.Assert(err, IsNil) c.Assert(strings.HasSuffix(result.Host, ":40012"), Equals, true) }
func (s *S) TestAuthAddUserReplaces(c *C) { session, err := mgo.Dial("localhost:40002") c.Assert(err, IsNil) defer session.Close() admindb := session.DB("admin") err = admindb.Login("root", "rapadura") c.Assert(err, IsNil) mydb := session.DB("mydb") err = mydb.AddUser("myuser", "myoldpass", false) c.Assert(err, IsNil) err = mydb.AddUser("myuser", "mynewpass", true) c.Assert(err, IsNil) admindb.Logout() err = mydb.Login("myuser", "myoldpass") c.Assert(err, ErrorMatches, "auth fails") err = mydb.Login("myuser", "mynewpass") c.Assert(err, IsNil) // ReadOnly flag was changed too. err = mydb.C("mycoll").Insert(M{"n": 1}) c.Assert(err, ErrorMatches, "unauthorized") }
func (s *S) TestAuthAddUser(c *C) { session, err := mgo.Dial("localhost:40002") c.Assert(err, IsNil) defer session.Close() admindb := session.DB("admin") err = admindb.Login("root", "rapadura") c.Assert(err, IsNil) mydb := session.DB("mydb") err = mydb.AddUser("myruser", "mypass", true) c.Assert(err, IsNil) err = mydb.AddUser("mywuser", "mypass", false) c.Assert(err, IsNil) err = mydb.Login("myruser", "mypass") c.Assert(err, IsNil) admindb.Logout() coll := session.DB("mydb").C("mycoll") err = coll.Insert(M{"n": 1}) c.Assert(err, ErrorMatches, "unauthorized") err = mydb.Login("mywuser", "mypass") c.Assert(err, IsNil) err = coll.Insert(M{"n": 1}) c.Assert(err, IsNil) }
func (s *S) TestAuthLoginSwitchUser(c *C) { session, err := mgo.Dial("localhost:40002") c.Assert(err, IsNil) defer session.Close() admindb := session.DB("admin") err = admindb.Login("root", "rapadura") c.Assert(err, IsNil) coll := session.DB("mydb").C("mycoll") err = coll.Insert(M{"n": 1}) c.Assert(err, IsNil) err = admindb.Login("reader", "rapadura") c.Assert(err, IsNil) // Can't write. err = coll.Insert(M{"n": 1}) c.Assert(err, ErrorMatches, "unauthorized") // But can read. result := struct{ N int }{} err = coll.Find(nil).One(&result) c.Assert(err, IsNil) c.Assert(result.N, Equals, 1) }
func (s *S) TestAuthLoginLogout(c *C) { // Test both with a normal database and with an authenticated shard. for _, addr := range []string{"localhost:40002", "localhost:40203"} { session, err := mgo.Dial(addr) c.Assert(err, IsNil) defer session.Close() admindb := session.DB("admin") err = admindb.Login("root", "rapadura") c.Assert(err, IsNil) admindb.Logout() coll := session.DB("mydb").C("mycoll") err = coll.Insert(M{"n": 1}) c.Assert(err, ErrorMatches, "unauthorized|need to login|not authorized .*") // Must have dropped auth from the session too. session = session.Copy() defer session.Close() coll = session.DB("mydb").C("mycoll") err = coll.Insert(M{"n": 1}) c.Assert(err, ErrorMatches, "unauthorized|need to login|not authorized .*") } }
func (s *S) TestAuthUpserUserOtherDBRoles(c *C) { if !s.versionAtLeast(2, 4) { c.Skip("UpsertUser only works on 2.4+") } session, err := mgo.Dial("localhost:40002") c.Assert(err, IsNil) defer session.Close() admindb := session.DB("admin") err = admindb.Login("root", "rapadura") c.Assert(err, IsNil) ruser := &mgo.User{ Username: "******", Password: "******", OtherDBRoles: map[string][]mgo.Role{"mydb": []mgo.Role{mgo.RoleRead}}, } err = admindb.UpsertUser(ruser) c.Assert(err, IsNil) defer admindb.RemoveUser("myruser") admindb.Logout() err = admindb.Login("myruser", "mypass") coll := session.DB("mydb").C("mycoll") err = coll.Insert(M{"n": 1}) c.Assert(err, ErrorMatches, "unauthorized|not authorized .*") err = coll.Find(nil).One(nil) c.Assert(err, Equals, mgo.ErrNotFound) }
func (s *S) TestAuthLoginChangePassword(c *C) { session, err := mgo.Dial("localhost:40002") c.Assert(err, IsNil) defer session.Close() admindb := session.DB("admin") err = admindb.Login("root", "rapadura") c.Assert(err, IsNil) mydb := session.DB("mydb") err = mydb.AddUser("myuser", "myoldpass", false) c.Assert(err, IsNil) err = mydb.Login("myuser", "myoldpass") c.Assert(err, IsNil) err = mydb.AddUser("myuser", "mynewpass", true) c.Assert(err, IsNil) err = mydb.Login("myuser", "mynewpass") c.Assert(err, IsNil) admindb.Logout() // The second login must be in effect, which means read-only. err = mydb.C("mycoll").Insert(M{"n": 1}) c.Assert(err, ErrorMatches, "unauthorized") }
func (s *S) TestGridFSRemove(c *C) { session, err := mgo.Dial("localhost:40011") c.Assert(err, IsNil) defer session.Close() db := session.DB("mydb") gfs := db.GridFS("fs") file, err := gfs.Create("myfile.txt") c.Assert(err, IsNil) file.Write([]byte{'1'}) file.Close() file, err = gfs.Create("myfile.txt") c.Assert(err, IsNil) file.Write([]byte{'2'}) file.Close() err = gfs.Remove("myfile.txt") c.Assert(err, IsNil) _, err = gfs.Open("myfile.txt") c.Assert(err == mgo.ErrNotFound, Equals, true) n, err := db.C("fs.chunks").Find(nil).Count() c.Assert(err, IsNil) c.Assert(n, Equals, 0) }
func (s *S) TestGridFSOpen(c *C) { session, err := mgo.Dial("localhost:40011") c.Assert(err, IsNil) defer session.Close() db := session.DB("mydb") gfs := db.GridFS("fs") file, err := gfs.Create("myfile.txt") c.Assert(err, IsNil) file.Write([]byte{'1'}) file.Close() file, err = gfs.Create("myfile.txt") c.Assert(err, IsNil) file.Write([]byte{'2'}) file.Close() file, err = gfs.Open("myfile.txt") c.Assert(err, IsNil) defer file.Close() var b [1]byte _, err = file.Read(b[:]) c.Assert(err, IsNil) c.Assert(string(b[:]), Equals, "2") }
func (s *S) TestPrimaryShutdownEventual(c *C) { if *fast { c.Skip("-fast") } session, err := mgo.Dial("localhost:40021") c.Assert(err, IsNil) defer session.Close() result := &struct{ Host string }{} err = session.Run("serverStatus", result) c.Assert(err, IsNil) master := result.Host session.SetMode(mgo.Eventual, true) // Should connect to the master when needed. coll := session.DB("mydb").C("mycoll") err = coll.Insert(M{"a": 1}) c.Assert(err, IsNil) // Kill the master. s.Stop(master) // Should still work, with the new master now. coll = session.DB("mydb").C("mycoll") err = coll.Insert(M{"a": 1}) c.Assert(err, IsNil) err = session.Run("serverStatus", result) c.Assert(err, IsNil) c.Assert(result.Host, Not(Equals), master) }
func (s *S) TestGridFSReadChunking(c *C) { session, err := mgo.Dial("localhost:40011") c.Assert(err, IsNil) defer session.Close() db := session.DB("mydb") gfs := db.GridFS("fs") file, err := gfs.Create("") c.Assert(err, IsNil) id := file.Id() file.SetChunkSize(5) n, err := file.Write([]byte("abcdefghijklmnopqrstuv")) c.Assert(err, IsNil) c.Assert(n, Equals, 22) err = file.Close() c.Assert(err, IsNil) file, err = gfs.OpenId(id) c.Assert(err, IsNil) b := make([]byte, 30) // Smaller than the chunk size. n, err = file.Read(b[:3]) c.Assert(err, IsNil) c.Assert(n, Equals, 3) c.Assert(b[:3], DeepEquals, []byte("abc")) // Boundary in the middle. n, err = file.Read(b[:4]) c.Assert(err, IsNil) c.Assert(n, Equals, 4) c.Assert(b[:4], DeepEquals, []byte("defg")) // Boundary at the end. n, err = file.Read(b[:3]) c.Assert(err, IsNil) c.Assert(n, Equals, 3) c.Assert(b[:3], DeepEquals, []byte("hij")) // Larger than the chunk size, with 3 chunks. n, err = file.Read(b) c.Assert(err, IsNil) c.Assert(n, Equals, 12) c.Assert(b[:12], DeepEquals, []byte("klmnopqrstuv")) n, err = file.Read(b) c.Assert(n, Equals, 0) c.Assert(err == io.EOF, Equals, true) err = file.Close() c.Assert(err, IsNil) }
func (s *S) TestAuthURLWrongCredentials(c *C) { session, err := mgo.Dial("mongodb://*****:*****@localhost:40002/") if session != nil { session.Close() } c.Assert(err, ErrorMatches, "auth fails") c.Assert(session, IsNil) }
func (s *S) TestAuthURL(c *C) { session, err := mgo.Dial("mongodb://*****:*****@localhost:40002/") c.Assert(err, IsNil) defer session.Close() err = session.DB("mydb").C("mycoll").Insert(M{"n": 1}) c.Assert(err, IsNil) }
func (s *S) TestGridFSOpenNext(c *C) { session, err := mgo.Dial("localhost:40011") c.Assert(err, IsNil) defer session.Close() db := session.DB("mydb") gfs := db.GridFS("fs") file, err := gfs.Create("myfile1.txt") c.Assert(err, IsNil) file.Write([]byte{'1'}) file.Close() file, err = gfs.Create("myfile2.txt") c.Assert(err, IsNil) file.Write([]byte{'2'}) file.Close() var f *mgo.GridFile var b [1]byte iter := gfs.Find(nil).Sort("-filename").Iter() ok := gfs.OpenNext(iter, &f) c.Assert(ok, Equals, true) c.Check(f.Name(), Equals, "myfile2.txt") _, err = f.Read(b[:]) c.Assert(err, IsNil) c.Assert(string(b[:]), Equals, "2") ok = gfs.OpenNext(iter, &f) c.Assert(ok, Equals, true) c.Check(f.Name(), Equals, "myfile1.txt") _, err = f.Read(b[:]) c.Assert(err, IsNil) c.Assert(string(b[:]), Equals, "1") ok = gfs.OpenNext(iter, &f) c.Assert(ok, Equals, false) c.Assert(iter.Err(), IsNil) c.Assert(f, IsNil) // Do it again with a more restrictive query to make sure // it's actually taken into account. iter = gfs.Find(bson.M{"filename": "myfile1.txt"}).Iter() ok = gfs.OpenNext(iter, &f) c.Assert(ok, Equals, true) c.Check(f.Name(), Equals, "myfile1.txt") ok = gfs.OpenNext(iter, &f) c.Assert(ok, Equals, false) c.Assert(iter.Err(), IsNil) c.Assert(f, IsNil) }
func getConnection(url string) (*mgo.Session, error) { session, err := mgo.Dial(url) if err != nil { return nil, err } session.SetMode(mgo.Monotonic, true) session.SetSafe(&mgo.Safe{}) // so we get an ErrNotFound error when deleting an absent key return session, nil }
func (mgw *MongoWrapper) getConnection() (*mgo.Session, error) { // TODO(mpl): do some "client caching" as in mysql, to avoid systematically dialing? session, err := mgo.Dial(mgw.url()) if err != nil { return nil, err } session.SetMode(mgo.Monotonic, true) session.SetSafe(&mgo.Safe{}) return session, nil }
func (s *S) TestAuthURLWithDatabase(c *C) { session, err := mgo.Dial("mongodb://*****:*****@localhost:40002") c.Assert(err, IsNil) defer session.Close() mydb := session.DB("mydb") err = mydb.AddUser("myruser", "mypass", true) c.Assert(err, IsNil) usession, err := mgo.Dial("mongodb://*****:*****@localhost:40002/mydb") c.Assert(err, IsNil) defer usession.Close() ucoll := usession.DB("mydb").C("mycoll") err = ucoll.FindId(0).One(nil) c.Assert(err, Equals, mgo.ErrNotFound) err = ucoll.Insert(M{"n": 1}) c.Assert(err, ErrorMatches, "unauthorized|not authorized .*") }
func (s *S) TestSetModeEventualIterBug(c *C) { session1, err := mgo.Dial("localhost:40011") c.Assert(err, IsNil) defer session1.Close() session1.SetMode(mgo.Eventual, false) coll1 := session1.DB("mydb").C("mycoll") const N = 100 for i := 0; i < N; i++ { err = coll1.Insert(M{"_id": i}) c.Assert(err, IsNil) } c.Logf("Waiting until secondary syncs") for { n, err := coll1.Count() c.Assert(err, IsNil) if n == N { c.Logf("Found all") break } } session2, err := mgo.Dial("localhost:40011") c.Assert(err, IsNil) defer session2.Close() session2.SetMode(mgo.Eventual, false) coll2 := session2.DB("mydb").C("mycoll") i := 0 iter := coll2.Find(nil).Batch(10).Iter() var result struct{} for iter.Next(&result) { i++ } c.Assert(iter.Close(), Equals, nil) c.Assert(i, Equals, N) }
func (s *S) SetUpSuite(c *C) { mgo.SetDebug(true) mgo.SetStats(true) s.StartAll() session, err := mgo.Dial("localhost:40001") c.Assert(err, IsNil) s.build, err = session.BuildInfo() c.Check(err, IsNil) session.Close() }
func getOpCounters(server string) (c *OpCounters, err error) { session, err := mgo.Dial(server + "?connect=direct") if err != nil { return nil, err } defer session.Close() session.SetMode(mgo.Monotonic, true) result := struct{ OpCounters }{} err = session.Run("serverStatus", &result) return &result.OpCounters, err }
// mongoSession returns an *mgo.Session or nil if c.dbtype is // not "mongo" or if there was an error. func (c *dbinitCmd) mongoSession() (*mgo.Session, error) { if c.dbType != "mongo" { return nil, nil } url := "" if c.user == "" || c.password == "" { url = c.host } else { url = c.user + ":" + c.password + "@" + c.host + "/" + c.dbName } return mgo.Dial(url) }
func (s *S) TestNewSession(c *C) { session, err := mgo.Dial("localhost:40001") c.Assert(err, IsNil) defer session.Close() // Do a dummy operation to wait for connection. coll := session.DB("mydb").C("mycoll") err = coll.Insert(M{"_id": 1}) c.Assert(err, IsNil) // Tweak safety and query settings to ensure other has copied those. session.SetSafe(nil) session.SetBatch(-1) other := session.New() defer other.Close() session.SetSafe(&mgo.Safe{}) // Clone was copied while session was unsafe, so no errors. otherColl := other.DB("mydb").C("mycoll") err = otherColl.Insert(M{"_id": 1}) c.Assert(err, IsNil) // Original session was made safe again. err = coll.Insert(M{"_id": 1}) c.Assert(err, NotNil) // With New(), each session has its own socket now. stats := mgo.GetStats() c.Assert(stats.MasterConns, Equals, 2) c.Assert(stats.SocketsInUse, Equals, 2) // Ensure query parameters were cloned. err = otherColl.Insert(M{"_id": 2}) c.Assert(err, IsNil) // Ping the database to ensure the nonce has been received already. c.Assert(other.Ping(), IsNil) mgo.ResetStats() iter := otherColl.Find(M{}).Iter() c.Assert(err, IsNil) m := M{} ok := iter.Next(m) c.Assert(ok, Equals, true) err = iter.Err() c.Assert(err, IsNil) // If Batch(-1) is in effect, a single document must have been received. stats = mgo.GetStats() c.Assert(stats.ReceivedDocs, Equals, 1) }
func (s *S) TestAuthLoginCachingAcrossPoolWithLogout(c *C) { // Now verify that logouts are properly flushed if they // are not revalidated after leaving the pool. session, err := mgo.Dial("localhost:40002") c.Assert(err, IsNil) defer session.Close() admindb := session.DB("admin") err = admindb.Login("root", "rapadura") c.Assert(err, IsNil) // Add another user to test the logout case at the same time. mydb := session.DB("mydb") err = mydb.AddUser("myuser", "mypass", true) c.Assert(err, IsNil) err = mydb.Login("myuser", "mypass") c.Assert(err, IsNil) // Just some data to query later. err = session.DB("mydb").C("mycoll").Insert(M{"n": 1}) c.Assert(err, IsNil) // Give socket back to pool. session.Refresh() // Brand new session, should use socket from the pool. other := session.New() defer other.Close() oldStats := mgo.GetStats() err = other.DB("mydb").Login("myuser", "mypass") c.Assert(err, IsNil) // Login was cached, so no ops. newStats := mgo.GetStats() c.Assert(newStats.SentOps, Equals, oldStats.SentOps) // Can't write, since root has been implicitly logged out // when the collection went into the pool, and not revalidated. err = other.DB("mydb").C("mycoll").Insert(M{"n": 1}) c.Assert(err, ErrorMatches, "unauthorized") // But can read due to the revalidated myuser login. result := struct{ N int }{} err = other.DB("mydb").C("mycoll").Find(nil).One(&result) c.Assert(err, IsNil) c.Assert(result.N, Equals, 1) }
func (s *S) TestAuthUpserUserUnsetFields(c *C) { if !s.versionAtLeast(2, 4) { c.Skip("UpsertUser only works on 2.4+") } session, err := mgo.Dial("localhost:40002") c.Assert(err, IsNil) defer session.Close() admindb := session.DB("admin") err = admindb.Login("root", "rapadura") c.Assert(err, IsNil) // Insert a user with most fields set. user := &mgo.User{ Username: "******", Password: "******", Roles: []mgo.Role{mgo.RoleRead}, OtherDBRoles: map[string][]mgo.Role{"mydb": []mgo.Role{mgo.RoleRead}}, } err = admindb.UpsertUser(user) c.Assert(err, IsNil) defer admindb.RemoveUser("myruser") // Now update the user with few things set. user = &mgo.User{ Username: "******", UserSource: "mydb", } err = admindb.UpsertUser(user) c.Assert(err, IsNil) // Everything that was unset must have been dropped. var userm M err = admindb.C("system.users").Find(M{"user": "******"}).One(&userm) c.Assert(err, IsNil) delete(userm, "_id") c.Assert(userm, DeepEquals, M{"user": "******", "userSource": "mydb", "roles": []interface{}{}}) // Now set password again... user = &mgo.User{ Username: "******", Password: "******", } err = admindb.UpsertUser(user) c.Assert(err, IsNil) // ... and assert that userSource has been dropped. err = admindb.C("system.users").Find(M{"user": "******"}).One(&userm) _, found := userm["userSource"] c.Assert(found, Equals, false) }
func (ins *instance) getConnection() (*mgo.Session, error) { if ins.session != nil { return ins.session, nil } // TODO(mpl): do some "client caching" as in mysql, to avoid systematically dialing? session, err := mgo.Dial(ins.url()) if err != nil { return nil, err } session.SetMode(mgo.Monotonic, true) session.SetSafe(&mgo.Safe{}) // so we get an ErrNotFound error when deleting an absent key ins.session = session return session, nil }