makes cache mode configurable

this makes the cache mode in the sqlite connection
string configurable. the default also changed from
shared to private to solve #107272 but allow the user
to use shared if performance is more important.

ref #10727

conf/defaults.ini

@@ -103,6 +103,9 @@ server_cert_name =
 # For "sqlite3" only, path relative to data_path setting
 path = grafana.db
 
+# For "sqlite3" only. cache mode setting used for connecting to the database
+cache_mode = private
+
 #################################### Session #############################
 [session]
 # Either "memory", "file", "redis", "mysql", "postgres", "memcache", default is "file"

conf/sample.ini

@@ -99,6 +99,9 @@
 # Set to true to log the sql calls and execution times.
 log_queries =
 
+# For "sqlite3" only. cache mode setting used for connecting to the database. (private, shared)
+;cache_mode = private
+
 #################################### Session ####################################
 [session]
 # Either "memory", "file", "redis", "mysql", "postgres", default is "file"

docs/sources/installation/configuration.md

@@ -250,6 +250,12 @@ Sets the maximum amount of time a connection may be reused. The default is 14400
 
 Set to `true` to log the sql calls and execution times.
 
+### cache_mode
+
+For "sqlite3" only. [Shared cache](https://www.sqlite.org/sharedcache.html) setting used for connecting to the database. (private, shared)
+Defaults to private.
+
+
 <hr />
 
 ## [security]

pkg/services/sqlstore/sqlstore.go

@@ -243,7 +243,7 @@ func (ss *SqlStore) buildConnectionString() (string, error) {
 			ss.dbCfg.Path = filepath.Join(ss.Cfg.DataPath, ss.dbCfg.Path)
 		}
 		os.MkdirAll(path.Dir(ss.dbCfg.Path), os.ModePerm)
-		cnnstr = "file:" + ss.dbCfg.Path + "?cache=shared&mode=rwc"
+		cnnstr = fmt.Sprintf("file:%s?cache=%s&mode=rwc", ss.dbCfg.Path, ss.dbCfg.CacheMode)
 	default:
 		return "", fmt.Errorf("Unknown database type: %s", ss.dbCfg.Type)
 	}
@@ -319,6 +319,8 @@ func (ss *SqlStore) readConfig() {
 	ss.dbCfg.ClientCertPath = sec.Key("client_cert_path").String()
 	ss.dbCfg.ServerCertName = sec.Key("server_cert_name").String()
 	ss.dbCfg.Path = sec.Key("path").MustString("data/grafana.db")
+
+	ss.dbCfg.CacheMode = sec.Key("cache_mode").MustString("private")
 }
 
 func InitTestDB(t *testing.T) *SqlStore {
@@ -391,13 +393,20 @@ func IsTestDbPostgres() bool {
 }
 
 type DatabaseConfig struct {
-	Type, Host, Name, User, Pwd, Path, SslMode string
-	CaCertPath                                 string
-	ClientKeyPath                              string
-	ClientCertPath                             string
-	ServerCertName                             string
-	ConnectionString                           string
-	MaxOpenConn                                int
-	MaxIdleConn                                int
-	ConnMaxLifetime                            int
+	Type             string
+	Host             string
+	Name             string
+	User             string
+	Pwd              string
+	Path             string
+	SslMode          string
+	CaCertPath       string
+	ClientKeyPath    string
+	ClientCertPath   string
+	ServerCertName   string
+	ConnectionString string
+	MaxOpenConn      int
+	MaxIdleConn      int
+	ConnMaxLifetime  int
+	CacheMode        string
 }