Getting top performance from a storage system and making applications faster and more resilient are two critical and challenging aspects of computing. Unfortunately, many products focus on just one side of the problem or require massive, costly infrastructure changes.
If that scenario sounds all too familiar, consider PolyServe Matrix Server, which combines a robust cluster file system with a virtual server architecture that enables failover and flexible allocation of computing resources. Matrix Server doesn’t require proprietary hardware and it runs on almost any Linux- or Windows-compatible server or storage device, so it’s easy to see why PolyServe captures the attention of partners such as HP, Microsoft, and Novell.
HP recently began bundling PolyServe Matrix Server with its StorageWorks Enterprise File Services Clustered Gateway. I looked at Matrix Server bundled with HP’s minimum configuration of two ProLiant DL380 servers running Windows Storage Server 2003. It’s a natural fit: HP’s servers are a solid foundation for clustering and the PolyServe software is the star of the show.
Squaring off with the SAN
Imagine a grid of applications and virtual servers that an administrator can easily and dynamically interconnect from a management console to provide failproof or load-balancing configurations. That’s PolyServe Matrix Server in a nutshell.
Explaining how Matrix Server works, however, is much easier than installing it, so purchasing the HP StorageWorks bundle with the applications already loaded gives you the benefit of having the product pre-installed on HP’s servers and the option of ordering installation services.
Using Matrix Server, you can create a cluster of as many as 16 Linux or Windows servers and dynamically assign multiple nodes to support your application. To allocate resources from those nodes to your apps, you define virtual servers and assign one or more to each application.
Another key component of Matrix Server is PSFS (PolyServe File System), which allows all the nodes in a cluster to safely share access to the same SAN volumes. Therefore, you can summon multiple servers to speed up your application and to provide immediate failover.
Activating these capabilities requires a rather complicated setup that touches just about every device in your data centre, including servers and SAN devices. For example, to monitor the status of the virtual servers, you need to connect each managed node to a service network over which the Matrix Server will constantly poll the status of each machine.
The servers’ access to the SAN is controlled via the usual zoning techniques, but Matrix Server will automatically discover which LUNs (logical unit numbers) are available and then monitor their status by following the IP address of the Fibre Channel switches. Also, the SAN volumes need to be imported into the Matrix Server managed pool and equipped with PSFS.
Many settings are human-driven, so errors are possible, but PolyServe includes good documentation and an application to ensure the major installation requirements are met. In the process, it creates a status report of errors and successful settings.
Once set up, I opened the Java-based management console, a grid with a row for each application and a column for each virtual server. In my test bed, those apps were Windows file shares, but PolyServe also controls databases and Web servers on Linux or Windows.
The intuitive colour-coded icons show whether the applications on particular rows are supported by servers on particular columns. Determining the number of virtual servers behind each app is as easy as counting how many green icons line up on its row.
Getting on the grid
You can manage other administrative tasks from the same GUI. From a context menu, you can dynamically remove or add servers according to each application’s performance demands. I also added another shared folder and assigned virtual servers to support it with the help of PolyServe’s wizards. The wizards collect data such as the name of the share, its physical path and the number of users allowed in a single window for easy input.
Choose how many virtual servers to assign to an app from a box that lists all physical nodes in the cluster. I selected two virtual servers and saw the change immediately reflected on the main screen matrix as two green arrows lined up with my new file share. That’s all you need to set up a redundant configuration, and that simplicity more than compensates for the time spent on a rather tedious installation.
From a user perspective, Matrix Server share is the same as working with any shared folder. To test my share’s resiliency, I started up a movie on my client, then unplugged the LAN cable from one of the two nodes assigned to my share. The movie continued undisturbed, and one of the console icons associated with my share turned from green to red, indicating a failed server.
After I restored the connection, the icon returned to green — and my movie was still running. I had only two servers assigned to that app, but Matrix Server’s clustered structure can provide multiple layers of failover.
Next, I tried adding a new SAN volume to the cluster and creating a new share. Matrix Server won’t help with the initial steps of creating a LUN and adding it to the zone; so use the native tools of your array, switch or other data centre devices.
I clicked “Storage”, then “Import disk” on the console menu and selected the new LUN from a list. After a successful import, I created a file system with one click and in a few minutes, without service interruption, I greatly increased the storage space available to my cluster.
Attaching more servers to the cluster is just as easy and adds processing power that can be shared among all users. PolyServe’s documentation says each additional server increases performance linearly, but I wasn’t able to reproduce that condition, because my clients didn’t have enough processing muscle to saturate even one server.
A good match
The combination of HP’s clustered hardware and PolyServe Matrix Server offers a unique combination that can pull out the fastest performance and superior reliability from your SAN and your servers. Installation may be challenging and deployment could require additional equipment, but these difficulties can be solved by HP’s bundled offering, for a fee.
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