The journey of virtual machine consolidation
The IRIS DMC technical staffs have been working in earnest to migrate all core functionality from traditional computer platforms to a Red Hat® Linux Enterprise Virtualization (RHEV) based virtual machine environment. The advantages of undertaking this effort, which allows the placement of a server virtual host on any available hardware configured for virtual machines are:
- Lower power usage: Having the same number of hosts on fewer computer units with power supplies cuts down excess power consumption and heat from intermittently idle machines.
- More effective crash recovery: Virtual machines that experience a critical failure can simply be redeployed to other hardware and resume current operations.
- Ease of maintenance: Hardware that needs to undergo servicing can be taken out of circulation without requiring the host to be shut down.
- Greater ability to tune: Virtual machines can be allocated only the resources they need. Should it be discovered that more CPU or memory is necessary, these can be quickly expanded without touching hardware.
- Greater ability to scale: Identical virtual machine configurations may be deployed in multitude to service a large number of users, and just as easily retracted.
The cost savings and added efficiencies from this move has motivated developers and administrators to make the switch in a number of different areas critical to DMC day to day operations.
The web services at the IRIS DMC have used virtualized Red Hat® Linux hosts for approximately one year and have benefitted from the flexibility afforded by such an environment. Virtualized hosts have been a good match for the parallelized web service architecture implemented at the DMC.
The data product development effort has also been successfully using virtual Red Hat® Linux hosts for over a year. The production systems were transferred from a hybridized environment with multiple operating systems to a simpler, uniform virtual host environment. The flexibility of virtual machines also allowed us to create test/beta environments for both web services and data product development.
The processes that retrieve and manage real time data at the DMC (IRIS BUD) are being moved to a virtual Red Hat® Linux server piece by piece. The move is being conducted in this manner due to the many software systems that must be migrated and also because the providers of real-time data, as their time allows, must record changes to these virtual host destinations. Despite this, the process of migration is well over half done.
The core IRIS DMS web site is currently in beta testing on virtual hosts, where it can take advantage of the richer, more modern, and more standardized Red Hat® Linux software ecosystem. Most of the site is on a shared file system, so the major challenge has been ensuring that components function correctly in both environments. Consequently, much of the effort has gone toward cleaning up dependencies and making components more modular, which yields the additional benefit of simplifying any future maintenance and modification in these systems.
The core IRIS database has also been transitioning to a Red Hat® Linux host, the principle difference being that it requires its own dedicated hardware, so is unable to take advantage of the benefits of virtual machines. Nonetheless, the operating system is the same as the other virtual platforms, so there is a great deal of uniformity from a software perspective.
Finally, IRIS software distributed to users receives a lot more scrutiny on Linux operating systems. Because of the wide variety of Linux choices available, the software developers make a best-effort evaluation on a few of the most common examples.
As IRIS DMC nears the completion of this task, the benefits are already becoming evident in terms of lower power load on the data center infrastructure, greater agility in host deployment and maintenance, and improved uptime of critical IRIS services at the DMC.
by Rob Casey (IRIS Data Management Center)