![Reboot to synchronize message and SQL log files [CR 467129]](arrow-right.gif){kind=icon}
The order in which you upgrade multiplex servers depends on the versions of Sybase IQ on the servers.
If you plan to run a mixed-version multiplex, you must upgrade query servers before the write server as described in the section “Running a mixed-version multiplex,” in Chapter 4, “Migrating data,” in the Sybase IQ Installation and Configuration Guide.
If you plan to run one version across the multiplex, you may upgrade servers in any order. You must shut down all multiplex servers, and after the write server is upgraded, synchronize query servers. See the section “Upgrading servers from 12.6 to 12.7” in the same chapter.
