Cluster patch behavior

When…	Actions...	The result…
Normal behavior.	The installer replaces current files with new.	Success, cluster is updated.
Installing an update and the patch history is missing (files are not found in the directory defined by the parameter PATCH_HISTORY_DIR in patch.conf)	The installer creates new history files in the directory. The installer cannot determine compatibility but installs anyway because an update is a full distribution.	Cluster is modified but if the update is not compatible (a previous version instead of newer version), the cluster may not work properly.
Installing a fix and the patch history is missing (files are not found in the directory defined by the parameter PATCH_HISTORY_DIR in patch.conf)	For a fix, the installer cannot determine compatibility.	No update, cluster remains in same state Error presented on screen and logged in patch.log and patch.err
The installer is partway through the installation when there is a problem. The cluster contains some older files and some newer files.	If the installer cannot complete, it reverses the update actions, removing the newer files and returning the older ones.	No update, cluster remains in same state. Error presented on screen and logged
Installing a fix and a file in the cluster is newer than the file in the patch (build number in cluster is larger than build number of patch).	Prompt user to overwrite or preserve file. Install other files in the patch as usual.	Each build of a file is backwards compatible, so this patch works properly with the newer file. Overwriting the newer file may break functionality of a newer patch in the cluster.
Installing a fix and a file in the cluster has been modified since the last patch (current file size does not match size that is recorded in patch history).	Prompt user to overwrite or exit.	Overwriting a corrupt file results in correct behavior. Overwriting a customized file breaks existing functionality. You can modify the updated file manually after installation. Patch functionality depends on updated content in the new file, so you cannot install the patch if you do not overwrite the file.