VxFlex OS Gateway High Availability Technical Notes VxFlex OS is a software-only solution that uses existing servers' local disks and LAN to create a virtual SAN that has all the benefits of external storage—but at a fraction of the cost and complexity. VxFlex OS utilizes the existing local internal storage and turns it into internal shared block storage. For many workloads, VxFlex OS storage is comparable to, or better than, external shared block storage. The VxFlex OS Gateway, which runs on Apache Tomcat, hosts a number of VxFlex OS features, including a REST gateway, VxFlex OS Installer, and SNMP trap sender. For high availability when two Apache Tomcat instances (VxFlex OS Gateway servers) are configured, use Apache httpd. Note: This document discusses procedures needed only in environments in which the REST API commands are used. Child Topics Overview of the high-availability solution To prevent a single point of failure in the Apache httpd, you can use a failover httpd instance that is clustered using one of the many available clustering stacks.