Summary

All hosts in a MarkLogic cluster of two or more servers must run the same MarkLogic Server installation package.

Operating System Architecture

MarkLogic Server installation packages are created for each supported operating system architecture (e.g. Windows 64 bit, Linux 64 bit …). Consequently, all hosts in a MarkLogic cluster must employ the same operating system architecture. 

Version

For MarkLogic 8 and previous releases, all hosts within a MarkLogic cluster must be running the same version of MarkLogic Server. Mixed version clusters are not recommended, are not tested by MarkLogic, and are not supported. The behavior of a mixed version cluster is not defined and could lead to corrupt or inconsistent data.

MarkLogic 9 and MarkLogic 10 include the "Rolling Upgrade" feature that allows a cluster to run on a mixed version for a very short period of time.  For additional details and restrictions, please refer to the Rolling Upgrade section of our Administrators Guide.

Security and Schema Databases

In a MarkLogic Cluster, if the Security databases is configured with a Schemas database, the forests must be placed on the same host.

Cluster Upgrades

When upgrading a MarkLogic cluster to a new release, the upgrade should occur on all hosts in the cluster within a short period of time. The first server to be upgraded must be the server on which the Security database is mounted. 

In addition to the MarkLogic Server’s Installation Guide, you will want to refer to the “Upgrading a Cluster to a New Maintenance Release of MarkLogic Server” section in the MarkLogic Server’s Scalability, Availability, and Failover Guide for details regarding the required procedure to upgrade a cluster.