MyXenApp

When troubleshooting a NetScaler appliance we should know the hard disk partition that is mounted on the /var directory. It differs according to the NetScaler appliance model.

To check free space:
root@netscaler# df –h
Filesystem Size Used Avail Capacity Mounted on
/dev/md0c 161M 156M 2.6M 98% /
/dev/ad0s1a 237M 133M 85M 61% /flash
/dev/da0s1e 23G 8.7G 13G 41% /var
procfs 4.0K 4.0K 0B 100% /proc

To verify the mount point on the /var directory:
root@netscaler# mount
/dev/md0c on / (ufs, local)
/dev/ad0s1a on /flash (ufs, local)
/dev/da0s1e on /var (ufs, local)
procfs on /proc (procfs, local)

The hard disk names for the various Citrix NetScaler appliance models:

The following models use the /dev/ad2s1e device name for the hard disk:
-7000
-9010
-10010
-12000 series

The following models use the /dev/ad4s1e device name for the hard disk:
-MPX-15000
-MPX-17000
-MPX-8200
-MPX-5650
-MPX-8015
-MPX-8005

The following models use the /dev/ad6s1e device name for the hard disk:
-MPX-5500***
-MPX-7500***
-MPX-9500***
-MPX-9700
-MPX-10500
-MPX-12500
-MPX-15500

These models may also use the /dev/ad0s1e device name for the hard disk, please check article CTX121853.

The following models use the /dev/ad8s1e device name for the hard disk:
-MPX-11500
-MPX-17550

The following model uses the /dev/da0s1e device name for the hard disk:
-9950

To mount a /flash drive on a NetScaler, we need a serial connection to the NetScaler appliance with the following specifications:

9600 bits per second
8 data bits
No parity
1 stop bit

To mount the missing flash drive, complete the following procedure:

1.Connect a console cable to the NetScaler appliance Serial Console.
2.Restart the NetScaler appliance.
3.Press the SPACEBAR key as soon as the following message is displayed:

Hit [Enter] to boot immediately, or any other key for command prompt
Booting [kernel] in 10 seconds

Note: On the NetScaler 7000 appliance, press the Ctrl+C keys simultaneously.

4.To start the kernel of the appliance in the single user mode, run the following command:
boot -s

5.Press the Enter key as soon as the following message is displayed:
Enter full pathname of shell or RETURN for /bin/sh:

Note: The prompt of the appliance changes to \u@\h\$.

6.Run the following command to verify the disk consistency:
\u@\h\$ /sbin/fsck <Device_Name>

7.Run the following command to verify if the flash drive is mounted:
\u@\h\$ df –k

8.If the output of the preceding command does not display the flash drive, then run the following command to mount the flash drive:
\u@\h\$ /sbin/mount <Device_Name> /flash

Note: For NetScaler 10.5, use -t ufs command with fsck and mount command.

9.Restart the NetScaler appliance.

10.From the shell prompt, run the following command to verify if the flash drive is mounted:
root # df –k

The MPX series appliances have a Cavium SSL accelerator card and this card has the ability to handle SSL encryption/decryption cycles using a hardware card, rather than consuming valuable CPU resources. The VPX can have the SSL offload feature enabled also, however as there is no Cavium card, the SSL offload performance is not as high as an MPX appliance

1. Create a server object

“SSL Offload -> Servers” and then select “add”

The webserver is named WinWeb01 and has an IP address of 10.10.0.5

2. Create a service object to reflect the HTTP service that is running on this web server.

A NetScaler service consists of a server object, a protocol, port and a monitor.

The monitor is used to determine if the service is available, if the service is unavailable the NetScaler will mark the service as down, removing it from load balancing decisions.

3. Create a NetScaler virtual server (vServer) and provide the following information and bind the service to the vServer.

Name
IP Address
Port
Bound services

The IP address of the vServer will be used by clients to connect to the backend services.

Bind a certificate to the vServer, this is certificate will be presented for client connections.

Client connections should now be directed to the vServer’s IP address – 10.10.0.100. The vServer will present the SSL certificate when a connection is made using HTTPS (TCP 443), any encryption/decryption of data will be processed using the NetScaler’s built in Cavium card.

In a Netscaler load balancing setup, the load balancing server is logically (virtual server) located between the client and the server farm, and manages traffic flow to the servers in the server farm. On the NetScaler appliance, the application servers are represented by virtual entities called Services.

The components of NetScaler load balancing setup:

1. Load balancing virtual server
The IP address, port, and protocol combination to which a client sends connection requests for a particular load-balanced website or application. If the application is accessible from the Internet, the virtual server IP (VIP) address is a public IP address. If the application is accessible only from the local area network (LAN) or wide area network (WAN), the VIP is usually a private (ICANN non-routable) IP address.

2. Service
The IP address, port, and protocol combination used to route requests to a specific load-balanced application server. A service can be a logical representation of the application server itself, or of an application running on a server that hosts multiple applications. After creating a service, you bind it to a load balancing virtual server.

3. Server object
A virtual entity that enables you to assign a name to a physical server instead of identifying the server by its IP address. If you create a server object, you can specify its name instead of the server’s IP address when you create a service. Otherwise, you must specify the server’s IP address when you create a service, and the IP address becomes the name of the server.

4. Monitor
An entity on the NetScaler appliance that tracks a service and ensures that it is operating correctly. The monitor periodically probes (or performs a health check on) each service to which you assign it. If the service does not respond within the time specified by the time-out, and a specified number of health checks fail, that service is marked DOWN. The NetScaler appliance then skips that service when performing load balancing, until the issues that caused the service to quit responding are fixed.

1. Create Server Objects

Configuration > Traffic Management  > Load Balancing > Servers > Add.

Provide web servers name and IP address, create 2 or more servers

2. Create Service Group

Configuration > Traffic Management  > Load Balancing > Service Groups > Add.

Provide Name the group and set the protocol to HTTP.

Click ‘No Service Group members’ and select server based. Select Port as 80 or 443.

3. Create “Monitors” to monitor the Service.

Click ‘No service Group to Monitor Binding’. Select pre-configured HTTP monitor and Bind.

4. Create Vitrual Server. Configuration > Traffic Management  > Load Balancing > Virtual Servers > Add.

Give the Virtual Server name, Protocol- HTTP, IP address and Port -80. This will be the VIP the NetScaler presents to the outside world.

Click ‘No load balancing Virtual Servers Service Group Binding’ and select the Service Group and Bind.

Some transaction based applications require persistence. For example, banking sites are interactive programs based on user input and selections. User logs on by providing a username and password and then the user can do a variety of tasks, such as checking account balance, transferring fund, etc. If persistence is not configured, user might have authenticated with Server 1, but his next request may go to Server 2 or Server 3.

In this case, the application will reject the user request since Server 2 or Server 3 does not have user’s transaction state & authentication details. If persistence is configured, all subsequent requests from the user will be directed to the server which got selected in the first request. In this example, all requests will be forwarded to Server 1.

Persistence can be configured for the following protocols: HTTP, SSL, IP, TCP, UDP, SIP, and RTSP. The administrator can configure persistence interval and persistence type based on the application requirement. NetScaler supports 10 persistence types. Netscaler can support 250K Persistent session for a core and some persistence types (CookieInsert) depends on the Netscaler memory limit. If persistence is configured for a particular domain, it takes precedence over the configured GSLB method. If the configured persistence applies to a site that is down, the NetScaler appliance uses a GSLB method to select a new site, and the new site becomes persistent for subsequent requests from the client.
Citrix recommends to configure the Cookie Insert persistence method on the NetScaler appliance when load balancing Citrix Web Interface servers.

Some persistence types:
Source IP, Cookie Insert, SSL Session ID, URL Passive, Custom Server ID, Rule, DESTIP, SRCIPDESTIP

To configure Cookie persistence by using commands:

> add lb vserver V1 http 10.120.80.50 80 -persistencetype COOKIEINSERT
Done
>
> add service S1 200.205,215.1 HTTP 80
Done
>
> add service S2 200.205,215.2 HTTP 80
Done
>
> add service S3 200.205,215.3 HTTP 80
Done
>
> bind lb vserver V1 S[1-3]
service “S1” bound
service “S2” bound
service “S3” bound
Done

To verify the cookie value of a service:

>show lb vserver V1

To capture the Service selection counter and Cookie persistence counter from NetScaler shell prompt:

nsconmsg -i V1 -s ConLb=1 -d oldconmsg

To configure Source IP Persistence by using commands:

> add lb vserver V1 http 10.120.80.50 80 -persistencetype sourceIP -timeout 5
Done
> bind lb vserver V1 S[1-3]
service “S1” bound
service “S2” bound
service “S3” bound
Done

To displays persistence session information:

> show persistentSessions -summary

Citrix XenApp and XenDesktop 7.x is the leading app and desktop virtualization platform that delivers a high-definition user experience on any device and a cloud service from Citrix Cloud. With Citrix XenApp 6.5 nearing End of Life (EOL) on 30th June-2018, many Citrix customers are planning to upgrade to XenApp and XenDesktop 7.x.

To understand this market trend a survey was conducted across 795 Citrix professionals during November 2017 and February 2018 around the world by a Citrix Ready partner. The results of this survey conducted have been compiled into an industry insight report, which will be helpful for any Citrix professional considering upgrading to XenApp and XenDesktop 7.x.

The survey was designed to find out about organizations’ migration plans, challenges, and performance expectations, as they plan their upgrade path. Analysis of the survey results helped shed light on when Citrix customers are planning to complete their migration, the factors driving the migration, adoption of Citrix Cloud, and many other interesting trends.

Here is a preview of some of the key findings:

2018 will be the year of Citrix migration. 70% of organizations are expected to complete the migration to XenApp and XenDesktop 7.x by the end of the year as older versions are nearing EOL.

The Long-term Service Release (LTSR), with 5 years of mainstream support, as well as support for Windows 10 are other important factors driving customers’ migration plans to 7.x.

45% are considering Citrix Cloud in the near future, and only 5% of respondents are already using Citrix Cloud.

90% of XenDesktop deployments are on version 7.x.

93% are running XenApp.

40% are running only XenApp and 7% are running only XenDesktop where as 53% are running both XenApp and XenDestop.

66% of respondents are running XenApp 7.x, and 65% are running 6.x.

18% of respondents are still running very old versions of XenApp.

There is a significant overlap between organizations using 7.x and 6.x. This indicates that organizations have deployed newer workloads on 7.x and they have continued on 6.x for the older applications and workloads.

Organizations are using multiple tools for monitoring their Citrix infrastructures. 91% agreed that having a single-pane-of-glass monitoring solution would simplify troubleshooting.

At 59%, slow logon continues to be the most common complaint faced by Citrix administrators. Measuring logon slowness is rated the most important aspect of Citrix user experience.

In large organizations (5,000+ employees), usage of 6.x, 5.x, and 4.x is comparatively higher.

The actual migration process does not seem to be a big concern for Citrix professionals. Only 19% of professionals have some reservations and fears about the steps involved during migration. This mainly applies to those migrating from 6.x to 7.x and about the pre-migration and post-migration phases.

The latest version of XA/XD 7.17 is only supported on Windows Server 2016 and 2012 R2.

75% respondents are considering using VMware vSphere hypervisor for XenApp and XenDesktop 7.x deployments.

Majority of respondents (67%) are using Citrix Director for performance monitoring. 28% are still using EdgeSight, which reaches EOL on June 30, 2018.

83% large organizations are using up to 10 tools for Citrix performance monitoring.

37% are not able to pinpoint infrastructure issues affecting Citrix performance. Most of the Citrix admins want to prove it is not Citrix that is causing a problem!

Performance monitoring for Citrix administration teams has become increasingly reactive and admins are constantly in a firefighting mode. 86% of respondents feel faster problem diagnosis and troubleshooting is their most critical need.

25% of Information Technology, 15% of Health Care and 10% of Financial Services industries use Citrix products