I got a notification,the notification is
You have one or more certificates in your Salesforce org [NAME + Orgid] that will expire soon. Please review the list below and visit Certificate and Key Management from Setup to make an update.
- SelfSignedCert_20Jan2014_160057, Self-Signed, expires on 1/20/2016. Warning: This certificate will expire in 30 day(s) which activity we need to perform for the certificate renew?