+ async execute () {
+ if (this.isRunning === true) return
+ this.isRunning = true
+
+ try {
+ await this.internalExecute()
+ } catch (err) {
+ logger.error('Cannot execute %s scheduler.', this.constructor.name, { err })
+ } finally {
+ this.isRunning = false
+ }
+ }
+
+ protected abstract internalExecute (): Promise<any> | Bluebird<any>