Troubleshooting NetScaler Configuration Utility launch failures

 

If you’re having problems launching the NetScaler Configuration Utility, here are a few troubleshooting steps which should come in handy. I was recently working with a customer that had a pair of boxes in one datacenter that worked just fine and a pair of boxes in another datacenter that failed to load.

  • Network Connectivity – Verify that you can ping and/or SSH into the NetScaler appliance(s).
  • Java Ports – Verify that you can connect to the ports used by Java. If you’re accessing the NetScaler GUI over HTTP then the Java port is TCP/3010. If you’re accessing the GUI over HTTPS then the Java port is TCP/3008. A simple telnet to the correct port should verify no firewalls are blocking communication.
  • Proxy Servers – Verify your browser and java proxy settings. Don’t overlook the java proxy settings and assume it matches/defers to your browser. This was ultimately my customer’s problem. Easiest way to test for errors is connecting to the java port from within your browser, e.g. http://<NSIP>:3010 or https://<NSIP>:3008. We had to change the java proxy settings to “Use Direct Connection” to resolve the launch issue.
  • Client Workstation – If possible, do a quick test from another workstation to ensure it’s not a connectivity problem specific to one machine.
  • Restart the HTTPD process on the NetScaler: http://support.citrix.com/article/CTX120034.
  • Last, but not least, break out Wireshark and do some tracing to pin-point where the communication flow is breaking down.
If you’ve got any other quick tips for troubleshooting this type of issue that I missed, post ‘em in the comments.
-LF

A stroll down memory lane, XenServer style.

With the much anticipated release of XenServer 6.0 on Monday, I got the urge to take a stroll down memory lane. For those that don’t know, I joined Citrix back in February 2008 and my sole responsibility was spreading the word about XenServer: educating partners, customers and those within Citrix that were used to virtualizing applications and desktops, not servers. I’m not an original XenSource guy, but I was picked for the team because I brought strong Linux/Storage experience. All of us on the team had our own unique talents and most importantly we brought a perspective to Citrix that was different from your traditional MetaFrame/Presentation Server/XenApp administrator.

My experiences that first year, from growing our install base to building the technical prowess of my local partners and fighting an uphill battle against the 800 lbs. gorilla in the datacenter built character, so to speak. We were the scrappy underdog, striving to make server virtualization ubiquitous and affordable, for all. We were little known, in the enterprise at least, and working at a feverish pace trying to get features into the product. We built scripts and utilities to help people unfamiliar with this thing we called dom0 and the xe CLI. I was the Linux shell scripter; another guy on the team kept going on about these Windows GUIs he could get built. Funny enough, both of us are still around and banging the XenServer drum on a daily basis.

Many of the challenges we faced back in 2008 are water under the bridge. We fought hard, built up our customer base and changed the server virtualization landscape for everyone involved. The features we lacked back in the early days of XenServer 4.0 and 4.1 are distant memories. In early 2009 we did the unthinkable and made a full-featured, free version of XenServer available for everyone to download. This set the stage for a serious uplift in awareness for XenServer. Downloads of the free edition went viral and a shift in marketing took the “10 to Xen” message to a new level.

Not wanting to rest on our laurels, the engineering team continued to innovate, launching XenServer 5.5 and becoming only the second hypervisor to be deemed Enterprise-Production Ready. A year later came XenServer 5.6 and with it a slew of new features, from enhancements to Workload Balancing to the inclusion of Role Based Access Control and a new Site Recovery feature. At the same time, our visibility in the cloud computing arena was picking up. Service Providers, seeing an opportunity to build their clouds on XenServer Free — and thanks to our simple per-server pricing, we could position XenServer Advanced or Enterprise and still be compelling against our competition — were quick to jump on board. Along with the announcement of XenServer 5.6 came news that Rackspace Cloud Servers would be standardizing their offering on XenServer.

And that brings us full circle to the release of XenServer 6.0, which includes tons of new features across all of Citrix’s core competencies.

  • Cloud – The full integration of Open vSwitch enables customers to design next-generation networks based on the OpenFlow standard. The number of articles I’ve found on Software Defined Networks and OpenFlow in public/private clouds is staggering, but this, this and this should get you started.
  • Virtualization – Doubling down on the value-proposition argument, XenServer 6.0 now includes the VM Protection and Recovery feature in all paid editions, i.e. Advanced and above. It’s also had its core engine, Xen, ugpraded to 4.1 and the supportability limits for both hosts and VMs are increased over previous editions.
  • Desktop – Fully supported to run the latest release of XenDesktop 5.5, XenServer 6.0 differentiates itself as an HDX-optimized platform thanks to the new GPU pass-through feature, which enables a physical GPU to be assigned to a VM providing high-end graphics capabilities, and the continued support and development of the IntelliCache feature.
For the full laundry-list of features, check out the New Features section of the XenServer 6.0 Release Notes.
-LF