Solved

F5 Load balancing

Posted on 2013-06-19
5
788 Views
Last Modified: 2013-06-20
I am putting tomcat web servers behind the F5 LB.  How does it balancing the load.  Per connection or per load on the server?  How much the load is too much per server?  How does it know when too much so to point to the next server?
Can anyone explain please?
0
Comment
Question by:Tiras25
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
5 Comments
 
LVL 57

Assisted Solution

by:giltjr
giltjr earned 500 total points
ID: 39261395
The F5 has multiple load balancing options:  You have to choose what is best for you.

Are all of the servers it will be front ending at the same physical location?
Are they all equal in performance?
Do you need to have session persistence?

Ref: http://www.fir3net.com/Big-IP-F5-LTM/f5-balacing-methods.html

You can choose:

Round Robin - Evenly distributes requests to all available pool members.

Ratio - Ratio allows each server to be assigned a ratio value. This is useful for pool members that have greater or lower computing resources then others. Example : Ratio 3:2:1:1. Based upon 8 requests, 3 requests would go to 1, 2 to 2 then 1 to 1.

Least Connections - Traffic is balanced to servers with the least total of current connections.

Fastest - Connections are distributed to pool members based upon server response time.

Observed - This method is the same as ratio but the ratio is assigned by BigIP.  Each ratio is calculated based upon the total number of connections currently active on each pool member. A pool member with a lower then average connection count is assigned a ratio of 3. A pool member with a higher than average count is given ratio of 2.

Predictive - Predictive is similar to observed but ratio`s are assigned using much more aggressive ratio values. A pool member with a lower then average connection count is assigned a ratio of 4. A pool member with a higher then average count is given ratio of 1.
0
 
LVL 17

Author Comment

by:Tiras25
ID: 39263184
Thank you very much for extensive answer.  Let me read through again and digest this.  

Yes, all the servers are windows virtual machines on ESX and will be in the same physical location.  They all will be an equal performance.  
Yes, we need a session persistence.
Thanks!
0
 
LVL 57

Assisted Solution

by:giltjr
giltjr earned 500 total points
ID: 39263500
With all servers being equal Round Robin is the suggested/preferred method of load balancing.

The F5 provides multiple methods of session persistence.  You can read the the doc to see what may be best for you.  Off hand I would say Cookie.
0
 
LVL 17

Author Comment

by:Tiras25
ID: 39263652
What would happen if one of the servers tomcats slows down.  Then I'd want the traffic to go to another web server.
0
 
LVL 57

Accepted Solution

by:
giltjr earned 500 total points
ID: 39263913
No problem.  The F5 can have two levels of monitoring.

First level is to ping the IP address of the host.
Second level would be a simple HTTP get of a static page that is served up by the tomcat server.

The either one of these fails, the F5 marks that node/service as being down and stops sending requests to it.
0

Featured Post

Save the day with this special offer from ATEN!

Save 30% on the CV211 using promo code EXPERTS30 now through April 30th. The ATEN CV211 connects a laptop directly to any server allowing you instant access to perform data maintenance and local operations, for quick troubleshooting, updating, service and repair.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
replacing 2811 to ISR 4331 2 48
Adnexus.net keeps getting hit from OpenDNS 12 62
Question about Buffalo NAS devices 4 54
Force a website to use the second network card 3 41
Short answer to this question: there is no effective WiFi manager in iOS devices as seen in Windows WiFi or Macbook OSx WiFi management, but this article will try and provide some amicable solutions to better suite your needs.
Most of the applications these days are on Cloud. Cloud is ubiquitous with many service providers in the market. Since it has many benefits such as cost reduction, software updates, remote access, disaster recovery and much more.
Internet Business Fax to Email Made Easy - With  eFax Corporate (http://www.enterprise.efax.com), you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, f…
In this tutorial you'll learn about bandwidth monitoring with flows and packet sniffing with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're interested in additional methods for monitoring bandwidt…

730 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question