Database and Application administration essential for Oracle E-Business Suite R12 upgrade
Guest post by
Umesh Tanna, Senior Technology Architect, Infosys
Oracle E-business suite R12 upgrade is a major project that organization undertakes. Functional, technical and infrastructure administration teams are the primary groups that are involved in upgrade project from IT department. Oracle Application Database Administration activities are very critical activities in upgrade project that is performed by Oracle Apps DBA. Following are most essential aspects of R12 upgrade project from the standpoint of Oracle Apps DBA.
This is the overall blueprint of R12 upgrade project. Database, application, availability/fault tolerance, disaster recovery, node topologies, performance expectation and last but not least - supported upgrade paths/procedures by Oracle are the important considerations while designing the upgrade solution.
- There is flexibility to choose from available upgrade paths based on the current application/database version.
- If the existing version is very old, then upgrade solution has to first upgrade to intermediate version and then finally to latest target version.
- Similarly, it is flexible to do both database and application upgrade in one large outage or one have choice of upgrading them separately over different week end to reduce the outage.
- If we want to change the platform (Ex. UNIX to Linux) then Oracle provides cross platform migration solution for upgrade.
- Another crucial decision while designing the solution is whether we are changing any architectural components or not as a part of the R12 upgrade.
- If there is no fault tolerance in the existing architecture, upgrade project may be the right opportunity to introduce it for ex. clustering of database (Oracle RAC) and load balanced application servers are probable candidate.
- In many cases where existing operating system version is quite old, in order to upgrade to latest version of R12, one has to upgrade the operating system first.
Perform due diligence of analyzing, evaluating, validating and then designing optimal upgrade solution that incorporates all the above aspects.
Research, Plan and Prepare
This is always self-explaining but is very important. Outcome of this should be documented steps and procedures to perform for upgrade. Give due focus to this activity to pre-empt the problems by proactively taking care of them. Though Oracle R12.x upgrade manual is available and is the main source of information for this, however, many latest information/finding is published in Oracle support sites and it is worth discovering all relevant information of project interest. For ex. Oracle now publishes consolidated upgrade patch to take care of the problems/bugs experienced during upgrade and incorporating such patch in our upgrade project proactively, makes the upgrade smooth. Reviewing the Readme, platform specific release note, Oracle upgrade center (A dedicated section in Oracle support site), Oracle white paper, and Oracle webcasts goes long way in preparing for smooth execution of upgrade.
Upgrade activity is highly complex activity and one has to expect that issues would be experienced that may be specific to organization's infrastructure, set up and configuration. Hence, multiple iterations of upgrade should be planned. Though based on the overall complexity this may vary but minimum three to four iterations should be planned to identify all the issues, resolving them and recording the fix applied. Iteration is also required to benchmark the various database and other parameters to optimize the execution time of upgrade. Intention is to have subsequent iterations as much flawless as possible and have reasonable repository of known problems/fixes rather than having surprise during go live.
Go Live and Outage Planning
In general overall upgrade execution takes several hours for typically sized installation. It is not uncommon to see this is taking much longer for highly complex and large sized environment.
- Identify the set of activities such as software installation that can be performed in advance to reduce the critical downtime.
- For environment having multiple nodes, plan to complete the upgrade in one node and then clone that to other nodes to save time rather than applying patches in all nodes.
- Merge the patches and then apply rather than applying individual large patch.
- Use the database and other patching procedure parameters that offered maximum benefits during iterations.
- Try to script as much work as possible rather than executing them interactively.
- Plan and execute dry run immediately before the go live to rehearse from start to finish involving multiple teams to achieve maximum coordination and orchestrating entire go live event to perfection.
Execute with excellence throughout the duration of project.
- Play attention to details. Don't assume or ignore. It may prove costly for ex. One must read Readme of patches to understand the pre-requisites and post -requisites action.
- Keep various tracker for ex. Patch tracker, configuration tracker (to keep recording of configuration item changed), Oracle SR tracker. Such trackers are very useful over complete project duration to have repeatable process.
- Avoid applying manual fix and insists on Oracle provide patch.
- Be extremely cautious doing anything that is unsupported.
- Perform the technical procedures consistently in multiple iterations to have desired outcome (except those controlled change that is carried out as correction or to optimize execution time).
- Upgrade project is long project. Keep practice of documenting what you do during upgrade or after upgrade as a fix.