Oracle has numerous database products in their cloud environment, and one that sees little attention is actually a cool product for small to medium workloads. It is popularly called "DBaaS", which stands for Database-as-a-Service.
DBaaS is a similar offering to Amazon's RDS (relational database service) in that it presents a complete and working managed database and is very simple to provision and build from the OCI (Oracle Cloud Interface) management console.
A DBaaS database can be built with standard linux file systems, but there are also options to build it with Grid Infrastructure and ASM for more flexible disk management. For more complete and detailed information, I refer you to the complete documentation.
Once built and provisioned, the Oracle database is yours to manage and maintain. Most routine administrative tasks can be performed from the console. Nightly backups are automatically scheduled when the system is provisioned. This makes administration and management much less of a chore.
However, certain tasks, as well as tuning and troubleshooting, can involve looking under the covers. This post centers around one area where it may be necessary to troubleshoot or run patching for databases that are unable to be patched from the console user interface.
DBCLI is a tool that can be used for a great many things in DBaaS.
It is a tool name and an acronym for "data base command line interface". It is only used on virtual machine systems with DBaaS.
Ironically there is another tool, called "dbaascli" which is only used for Exadata Cloud systems.
dbcli is necessary to be used for patching DBaaS databases and systems in certain cases. One such case is with a database supporting Enterprise Business Suite (EBS). Another, of course, is when the console patching fails.
To patch a database, there are two fairly simple commands to run:
dbcli update-dbhome -i dbhomeid --version 19.16.0.0.0 --precheck
dbcli update-dbhome -i dbhomeid --version 19.16.0.0.0
A precheck is first necessary, as when doing traditional patching with the opatch utility, because it checks if the in-place Oracle home is in good condition, that the patch is available on the system and is complete, and that the system itself is ready to accept the patch.
(this saves over half-a-dozen manual checks in opatch)!
The patching itself does numerous things, including shutting down the connected database and listener, which normally would be done manually by the DBA. While this is a timesaver, please note it is a potentially troublesome issue if applications or sessions are connected, as they will be terminated!
I am making this post as simple as possible, but if you need to obtain the dbhomeid for your server, there is a command for that as well:
dbcli list-dbhomes
dbcli list-dbhomes
ID Name DB Version Home Location Status
---------------------------------------- -------------------- ---------------------------------------- --------------------------------------------- ----------
f5c954e1-9f8c-4470-b994-d5e29ca97399 OraDB19000_home1 19.15.0.0.0 /u01/app/oracle/product/19.0.0.0/dbhome_1 Configured
All dbcli commands must be run as root. If the command itself is not found, you should open a support request with Oracle, because it is an essential part of the tooling for a provisioned DBaaS system. In fact, Oracle uses it in the background to take backups, verify system integrity and monitoring.
Were the dbcli command itself to fail, refer to /opt/oracle/dcs/log directory for logs specific to the tool, such as dcscli.0.0.log and dcs-agent.0.0.log . These will usually contain detailed information as to why the command failed. If not, they will be required by Oracle support to do troubleshooting!
For more detailed information specific to this utility, please refer to the dbcli documentation. It might also be wise to check this before you begin, as these tools and products are constantly evolving, and some of the syntax here might change over time. There is also information about how to repair and update the version for this tool within the above documentation.
Prerequisites:
This post assumes you are running the latest version of the dbcli utilty. it must also be patched from time to time. This is a topic for a future post.
Grid Infrastructure and ASM must also be patched if your DBaaS VM is built using these features. I will cover this in a future post as well.
If your DBaaS system is a RAC cluster, patching is more or less the same. In fact, the patches are run, by detault, in a "rolling upgrade" fashion, usually without downtime. This can be overriden, but that is usally a bad idea. I will look into posting on this in a future blog.
That's all for now. Let me know in the comments if you have any questions or have used this tool. I would love to hear from you!
