The Apache Haus Forum

Forum Topics => Apache 2.2 => Topic started by: yellowdef on July 10, 2015, 08:44:35 AM

Title: Load balancer
Post by: yellowdef on July 10, 2015, 08:44:35 AM
we are currently using the proxy load balancer for an application on 4 tomcat instances on 2 servers .
In the LB manager I  have the following output :
Worker URL   Route   RouteRedir   Factor   Set   Status   Elected   To   From
http://server1:8080   jvm01      1   0   Ok   3835358   6.5G   19G
http://server1:8081   jvm02      1   0   Ok   1725121   2.3G   20G
http://server2:8080   jvm03      1   0   Ok   6902324   12G   23G
http://server2:8081   jvm04      1   0   Ok   1730042   2.3G   19G

I have a number of questions :
1) the elected number : where is this stored ?
2) what is the meaning of TO and FROM .What are these units ...G
3) Can I reset these values ?

Settings are as follows
<Proxy balancer://e_cluster>
    BalancerMember http://server1:8080 route=jvm01 loadfactor=1
    BalancerMember http://server1:8081 route=jvm02 loadfactor=1
   BalancerMember http://server2:8080 route=jvm03 loadfactor=1
   BalancerMember http://server2:8081 route=jvm04 loadfactor=1
   #ProxySet lbmethod=bytraffic
   ProxySet lbmethod=byrequests
   ProxySet stickysession=JSESSIONID|jsessionid
   ProxySet nofailover=off

thanks for the help
Title: Re: Load balancer
Post by: Gregg on July 14, 2015, 02:50:22 AM
I was hoping Mario would chime in on this, he has much more experience with this sort of thing than I. That said looking through the code for the module;

1) Where it's stored may depend on the version and OS. I do not know I only have a guesses. As for what it means, I have no idea.
2) transfered from balancer to server/recieved from server
3) I'd imagine Gigabytes
Title: Re: Load balancer
Post by: mario on July 14, 2015, 10:57:12 AM
since the Balancer Manager is an extension of mod_status you have to restart apache to reset that stuff.

Yes the G is Gigabytes. Since you run a tomcat you should try to use mod_proxy_ajp which is much faster an saves a lot of traffic. Also it often solves some keep alive problem ( if you encounter them)

The elected number is part of the rumtime data. That is stored in the httpd's scoreboard or shared memory.
Title: Load balancer
Post by: StevenTut on January 09, 2017, 12:45:14 PM
I will set up a load balancer to a cluster of 5 servers. The load balancer wont have cache. Is there a need of a fast cpu and much ram or can it be an older computer?
Title: Re: Load balancer
Post by: mario on January 13, 2017, 10:45:08 AM
There is no need of "much" ram. On Windows Server OS 4GB are okay. A dual core CPU is mostly sufficiant. However, with a high traffic site you may need more CPU and more RAM.
if you can then you should put the static content on the loadbalancer itself.