Increase stability by exposing DB connection and pool properties

lib/caconfig.go

@@ -125,9 +125,13 @@ type CAInfo struct {
 
 // CAConfigDB is the database part of the server's config
 type CAConfigDB struct {
-	Type       string `def:"sqlite3" help:"Type of database; one of: sqlite3, postgres, mysql"`
-	Datasource string `def:"fabric-ca-server.db" help:"Data source which is database specific"`
-	TLS        tls.ClientTLSConfig
+	Type            string `def:"sqlite3" help:"Type of database; one of: sqlite3, postgres, mysql"`
+	Datasource      string `def:"fabric-ca-server.db" help:"Data source which is database specific"`
+	TLS             tls.ClientTLSConfig
+	MaxIdleConns    int           `def:"2" help:"Maximum number of connections in the idle pool; default is 2"`
+	MaxOpenConns    int           `def:"0" help:"Maximum number of open database connections; default is infinite or zero"`
+	ConnMaxIdleTime time.Duration `def:"15m" help:"Maximum amount of time a connection may be idle; default is infinite or zero"`
+	ConnMaxLifetime time.Duration `def:"30m" help:"Maximum amount of time a connection may be reused; default is infinite or zero"`
 }
 
 // Implements Stringer interface for CAConfigDB

lib/server/db/db.go

@@ -36,7 +36,10 @@ type FabricCADB interface {
 	Rebind(query string) string
 	MustBegin() *sqlx.Tx
 	Close() error
+	SetMaxIdleConns(n int)
 	SetMaxOpenConns(n int)
+	SetConnMaxLifetime(d time.Duration)
+	SetConnMaxIdleTime(d time.Duration)
 	PingContext(ctx context.Context) error
 }
 
@@ -54,7 +57,10 @@ type SqlxDB interface {
 	Rebind(query string) string
 	MustBegin() *sqlx.Tx
 	Close() error
+	SetMaxIdleConns(n int)
 	SetMaxOpenConns(n int)
+	SetConnMaxIdleTime(d time.Duration)
+	SetConnMaxLifetime(d time.Duration)
 	PingContext(ctx context.Context) error
 }
 
@@ -169,11 +175,34 @@ func (db *DB) Close() error {
 	return db.DB.Close()
 }
 
+// SetMaxIdleConns sets the maximum number of connections in the idle connection pool.
+// The default is 2
+// See database/sql/sql.go:SetMaxIdleConns for further information
+func (db *DB) SetMaxIdleConns(n int) {
+	db.DB.SetMaxIdleConns(n)
+}
+
 // SetMaxOpenConns sets number of max open connections
 func (db *DB) SetMaxOpenConns(n int) {
 	db.DB.SetMaxOpenConns(n)
 }
 
+// SetConnMaxIdleTime defines the maximum length of time a connection can be idle for before being
+// optionally closed lazily before reuse.
+func (db *DB) SetConnMaxIdleTime(d time.Duration) {
+	db.DB.SetConnMaxIdleTime(d)
+}
+
+// SetConnMaxLifetime sets the lifetime of the open connections.
+// 0 is the default duration set in the underlying database/sql library meaning
+// connections have an infinite life and are not closed based on a connection's age.
+// Setting this to a non-zero value is useful for recycling connections
+//
+// Works for each Postgres, MySQL, and SQLite since they all use sqlx and database/sql
+func (db *DB) SetConnMaxLifetime(d time.Duration) {
+	db.DB.SetConnMaxLifetime(d)
+}
+
 // PingContext pings the database
 func (db *DB) PingContext(ctx context.Context) error {
 	return db.DB.PingContext(ctx)