Give NetScaler a "tune-up"

Give NetScaler a "tune-up"

https://www.citrix.com/blogs/2014/10/21/give-netscaler-a-tune-up/

To Optimize TCP traffic

If you ' re wondering, there are no little knob to turn. But, Providence are on your side, as the NetScaler have an excellent tool-kit so can leverage to optimize TCP flows th Rough the appliance.

In fact, it's the perfect time to ensure that your NetScaler appliance are correctly optimized with a baseline TCP profil E. With the right information, you can very easily tweak on your NetScaler appliance to optimize TCP traffic.

The very best place-to-start tuning up your NetScaler are at the Global Settings level. Simply log into the appliance via the GUI, navigate to the System node, then Settingsand select Change TCP parameters on T He right side of the screen as reflected below:

Stage (1) Tune

You'll want to ensure. Windows Scaling is enabled.

What is Window scaling?

Window scaling allows end-points to increase/decrease the TCP receive window, effectively increasing or decreasing the EFF Ective bandwidth that's allowed in TCP streams.

Other detailed explanations:
TCP Window Scaling RFC 1323–https://www.ietf.org/rfc/rfc1323.txt
Wikipedia-http://en.wikipedia.org/wiki/tcp_window_scale_option.

Stage (2) Tune

You'll want to also ensure the SACK (selective acknowledgement) is enabled.

What's this SACK?

SACK improves TCP throughput by only retransmitting a portion of the TCP window, depending on what segments could have been lo St during transmission of course. Avoiding the need to retransmit the entire TCP window would positively increase the overall throughput capability, and thus Improve the user experience.

For a detailed explanation on SACK, reference the RFC:
SACK (selective acknowledgement) –http://tools.ietf.org/html/rfc2018

Improved TCP performance–http://packetlife.net/blog/2010/jun/17/tcp-selective-acknowledgments-sack/.

Stage (3) Tune

You'll be want to enable Nagle ' s.

The main reason that want to enable Nagle's if you ' re dealing with lots of small packets being transmitted thro Ugh the NetScaler. Take a look at the following URL for a description of Nagle ' S–http://en.wikipedia.org/wiki/nagle ' s_algorithm. In short, enabling Nagle ' s allows the NetScaler to group or combine a number of small outgoing messages/packets into a tra Nsaction, once 2*mss worth of data is outstanding on the wire, and send them all at once. Proceed with caution on enabling Nagle ' s at the Global level, as enabling this feature could cause issues with traffic that Isn ' t small in nature.

Give It a ' Custom Tune '

As a note, for Window scaling, the default value is (4). If you ' re dealing with long, fat pipes and is frequently transmitting very large files, such as virtual machine images or Perhaps an ISO, increasing the Window scaling to a value of (6) should provide better performance than the default (4) VA Lue.

To create a custom TCP profiles, navigate to the Traffic Management node, then Load balancing and Virtual Servers and Selec T a vServer that you would like to add a TCP profiles to. Click on Profiles on the "the" screen:

Click on the (+) option to begin creating a, the custom TCP profile, that is only being applied to the selected Virtual Server.

Simply fill out the profiles with the values desired, click Create and your ' ll have a customer TPC ' tune ' profiles on that SE Lected VServer.

reference:http://support.citrix.com/article/ctx121149

Does you have any custom TCP profiles created? Why isn't leave a comment with examples of what you ' ve given your NetScaler a ' appliance '.

Give NetScaler A "tune-up"