ORA-12545 TNS: Host or Object Does not Exist , while using SCAN

As part of SSL configuration between WebLogic tier and DB tier, post sqlnet.ora settings and scan listener restart, we encountered an ORA-12545 error on a 3 node RAC database when using the SCAN listener.

We verified the LISTENER status and we could find all the services in READY status. Tried using VIP, it worked perfectly. So, the only issue was connecting through SCAN. We were fortunate to find a solution after a very quick search over the net. The MOS Doc 364855.1 explained the issue and provided the solution.

As part of the configuration, we set the LOCAL_LISTENER to an VIP hostname. After modifying the LOCAL_LISTENER string to point to VIP IP address, we could manage to connect through the SCAN.

Logically the VIP hostname should have worked, but, we noticed through many references the same issue. 

Client Connection to RAC Intermittently Fails-ORA-12545 TNS: Host or Object Does not Exist (Doc ID 364855.1)


Backup2Cloud - a backup/restore automation utility

For cost optimization and flexibility, its a good idea to go with Oracle Database backup cloud services. The Oracle Database Backup Cloud service can actually compliment with the existing backup strategy by providing an off-site storage location in the cloud.

The bck2cloud utility is easy to use, install and secures the data. It simplifies the RMAN backup/restore operations when using the Oracle Backup Cloud Services. Once you subscribe to the service, you simply need to download  module from the OTN and install it on the database host. Once the module is successfully installed, you then need to configure the RMAN settings. With the utility, all data transfers strictly between the database instance and Oracle backup cloud account controlled by the customer.

Following operations are supported by the utility:

  • RMAN Operations
  • Cloud Storage operations
  • Password Encryption operation
  • Install Oracle Public Cloud (OPC) Module operation

Bck2Cloud simplifies and perform many RMAN operations:
  • Backup : all levels/types of backups (full, incremental, spfile, controlfile etc)
  • BckReport : provides information about all backups
  • BValidate : Validates backups
  • Crosscheck :
  • DelBck
  • ListBck
  • ListInc
  • Recovery
  • Restore
  • RPreview
  • Rvalidate

For more details and examples, read the Oracle White paper mentioned below:



Benefits from Oracle Backup to could service

Organizations treat their data as an asset. In this regards, the top priority for them is data availability and protection from all sorts of disasters. We have seen more and more organizations investing huge amount of money to achieve continuous data availability and safeguard the data form any aspects. Keeping the data backups off-site also become one of the critical factors of data protection policy. Traditionally, following model is followed by many organizations (image taken from Oracle white paper)

Oracle database backup cloud service offers very flexible and strong protection from disasters:
  1. Backups are always available over the internet and for immediate recovery need
  2. Data is transparently replicated across multiple nodes in the same geographic region
  3. Provided end-to-end security
  4. Supports all levels of Oracle editions, DB version >=10.2.5, and compressions
  5. Supports all RMAN operations
  6. low cost solution
  7. leverages MAA configuration and BP
  8.  Guaranteed backup and recovery operations
High level of OCB architecture:

on-premises End-to-End flow example

 Cloud end-to-end flow example: