The following are general requirements for both online upgrade and online reversion of the SGC.
The cluster must consist of at least two nodes.
Single node clusters can still be upgraded or reverted via the online upgrade method, but there will be a period of service loss during the process.
Each cluster member must be configured such that it can operate as the only cluster member in the event of failure or administrative shutdown of all other cluster members. This is a standard SGC clustering requirement and is not specific to the upgrade or reversion process.
backup-countmust be correctly configured in the existing cluster’s
hazelcast.xmlconfiguration files. If this is not correctly specified, then the risk of catastrophic cluster failure exists. This risk is not specific to the upgrade or reversion process, but must be corrected before an online upgrade or reversion is attempted.
In addition, the following general requirements apply:
The newest (highest) SGC version must support online upgrade from the oldest (lowest) SGC version. This applies regardless of whether upgrade or revert is being performed. i.e. If it’s possible to online upgrade from 126.96.36.199 to 188.8.131.52 it will also be possible to perform an online revert from 184.108.40.206 to 220.127.116.11. See the Online Upgrade Support Matrix for information on which SGC release combinations support this process.
Configuration files (such as
SGC.properties) must be contained within the OCSS7 installation directory or sub-directory, not located elsewhere on the filesystem. The default SGC installation structure meets this requirement.
The SGC’s log files, configured via the
sgcenv, may be located anywhere on the filesystem, including outside of the OCSS7 installation directory.