Load Balancing
==============

Static Load Balancing
---------------------

In the task, you will look and the various effects of different load
balancing configurations.

Open the **www\_pool Members** tab.

Note the load balancing method on the pool and the **Ratio** and
**Priority** settings on the members. Select each member and update them
to the following:

+--------------+-------------+----------------+
| **Member**   | **Ratio**   | **Priority**   |
+==============+=============+================+
| 10.1.20.11   | 5           | 10             |
+--------------+-------------+----------------+
| 10.1.20.12   | 1           | 10             |
+--------------+-------------+----------------+
| 10.1.20.13   | 1           | 5              |
+--------------+-------------+----------------+

Go to Local **Traffic > Pools > Statistics** and clear the **www\_pool**
statistics.

Browse to **http://10.1.10.100** and  **F5** at least 10
times.

*Q1. Which* **www\_pool** *members was traffic sent to?*

*Q2. Did member* **10.1.20.11** *receive the most traffic?   Why not?*

Under the **Members** tab change **Load Balancing Method** to **Ratio
(member)** then **Update**.

Clear stats for **www\_pool** and browse **http://10.1.10.100** several
times.

Browse to **http://10.1.10.100** and  **F5** at least 10
times.

*Q3. Which* **www\_pool** *members was traffic sent to?*

*Q4. Did member* **10.1.20.11** *receive the most traffic?*

Priority Group Activation
-------------------------

On the **www_pool** change the **Load Balancing Method** back to **Round Robin**. 

Change **Priority Group Activation** to less than 2 and **Update**.

Clear statistics for **www\_pool** and browse to **http://10.1.10.100** hitting **F5** several times.

*Q1. Which* **www\_pool** *members was traffic sent to?*

On the pool statistics page, select member **10.1.20.11:80** and change
the **State** to **Disable.**

Clear statistics for **www\_pool** and browse to **http://10.1.10.100** hitting **F5** several times.


*Q2. Which* **www\_pool** *members was traffic sent to?  Why?*

*Q3. Would the results have been different if 10.1.20.11:80 had been
marked offline or marked with a yellow triangle?*

.. IMPORTANT::

   Once you have complete the lab, change then **Load
   Balancing Method** to **Round Robin**, **Priority Group** to
   **Disabled**, and **Enable** pool member **10.1.20.11:80**

Effects of Persistence on Load Balancing
----------------------------------------

In this task, you will enable persistence on the **www\_vs** and see the
effects of persistence on load balancing. You will also see where to
view persistence records that are maintain by the BIG-IP

Enable a **Persistence Profile** on **www\_vs** by opening the virtual
server and selecting the **Resources** tab.

Assign the following persistence profiles::

   Default Persistence Profile:  cookie
   Fallback Persistance_Profile: source_addr

Did you see an error requiring an HTTP profile? Correct the error by assigning the HTTP profile to the virtual server.

*Q1. Why was a http profile required?*

Clear stats for **www\_pool** and browse to **http://10.1.10.100** hitting **F5** or refresh several times.

*Q2. Was traffic evenly distributed to all* **www\_pool** *members? Why
not?*

Place the pointer in the web page and right click and selectg **Inspect**.  Select **Network** from the top bar in the right window and refresh the page.

Select 10.1.10.100 in the **Name** section and look at the **Headers** in the **Cookie** header you will see the BIG-IP cookie named **BIGipServerwww_pool**.

.. image:: /_static/201L/cookie-persistence.png

Open **Statistic > Module Statistics > Local Traffic > Persistence
Records**

Click on pool member displayed on persistence record and **Disable** the
pool member.

Browse to **http://10.1.10.100**.

*Q3. Did you persist to the Disabled member?  Why?*

Change status of persisted pool member to **Forced Offline**

The cookie persisted records should still exist.  Browse to **http://10.1.10.100**.

*Q4. Does traffic continue to persist to the member Forced Offline?*

*Q5. If cookies were disable on your browser would persistence still
work?  Why?*

.. admonition:: TMSH

   An Alternate method to display persistence is:
 
   **show ltm persistence persist-records**