Patching and Upgrade Timing AdviceThis article has some useful suggestions and information regarding patching and upgrade CHGs and can help ensure a smooth transition. We recommend that a FULL test upgrade on at least one sub production instance should be completed for accurate timings for the production instance's upgrade, i.e. don’t exclude any tables. This will provide realistic time frames for the production instance and ensure there is a sufficient change window available. We also recommend that you should check that the WAR file version differs between the instance and the upgrade server. If this is not different the CHG will not start despite being scheduled. There may be delays in HI's scheduled jobs which affect the start time of an upgrade. If these delays are longer than 4 hours, a case is automatically created. These occasions are fortunately few and far between, but you need to be aware these things may happen and are a risk that should be taken into account. You can, of course, call in and open a Case before the 4-hour period has passed if you have concerns regarding the CHG. Your instances will check in on the assigned WAR file change hourly by default, but this can be changed to a higher or lower value. This means if it is set to default and checks in at, say, 23:33 and a CHG is scheduled for 00:00 then the CHG will not start at 00:00. The instance will check in again at 00:33, see the difference in WAR file versions, know a CHG is scheduled and start at 00:33. To help with this you can click on the Check now button before the CHG is due to start so the instance is aware of a WAR file difference and at the time of the CHG it will begin straight away. Upgrade Monitor that has the "Check Now" button Alternatively, if you don't want to perform this manual step, a few hours before the CHG is due you can set the interval of the scheduled job that checks whether an upgrade needs to be performed to run every few minutes so the CHG starts very close to the start time. After the upgrade, you will need to set the interval of this job back to back its previous value to reduce demand on HI servers (see: KB0743666 - How to Trigger your Instance Upgrade for more information). CHG ID in HI which is customer visible with Planned Start Date and Actual Work Start The CHG starts with a download of the WAR file and updating the upgrade server, which may take ~5-10 minutes or maybe longer depending on how the instance is configured, customized etc. Even though the CHG has started, there may not be visible signs of this in the portal, however, you will see activity in the log files. Upgrade Log on an instance that has entry when downloading the upgrade artifact