HA Proxy/F5 - DWP/SmartIT/Midtier

Knowledge Article

Article Number

000206406

Old Article Number

000178990

Article Type

Solutions to a Product Problem

Title

HA Proxy/F5 - DWP/SmartIT/Midtier

Summary

We are using HA Proxy as a load balancer for our Tomcat Webservers.
Is there any documentation on how to achieve this for BMC Apps?
Citrix Netscaler considerations

Product

BMC Digital Workplace Advanced

Component

Applies to

Any Tomcat/Jetty server - Target audience 18.05 and beyond.
SmartIT, DWP. SmartIT

Problem

We are using an Open Source solution for Loadbalancing: HA Proxy and don't know how to configure this and make it work.
For SmartIT, check 000173915

Cause

This is not officially supported by BMC.
This has worked on internal labs and several customer's servers.
Use at your own risk.
Test this first prior deploying on Production/Go-lives/POC environments

Solution

This knowledge article may contain information that does not apply to version 21.05 or later which runs in a container environment. Please refer to Article Number 000385088 for more information about troubleshooting BMC products in containers.

PREREQUIRED

RSSO NEEDS TO BE INSTALLED AND CONFIGURED FOR DWP, THIS WILL MAKE SESSION FAIL OVER WORK.

Load balancing with the sticky option applies on both F5 and HA Proxy, insert cookie option needs to be in place.
Need to have a rule to rewrite http to https.

The "sticky" or "persistence" option ensures that a single client gets the same real AR System server for each interaction with the load balancer. This is a requirement for AR System because:

User instance information is cached on the server.
If data flowing from the server is associated with an API call returning a large result set, and the data is split over multiple client/server exchanges, it is necessary to interact with the server on which the interaction originated.
If encryption is in use, encryption keys are exchanged in a handshaking arrangement that requires the client to return to the server that provided the key.

SEE KA 000026873

NOTES:

HA Proxy official doc site:

https://www.haproxy.com/blog/load-balancing-affinity-persistence-sticky-sessions-what-you-need-to-know

Whether your have HA Proxy or not (F5 in place), make sure you perform below steps for Jetty and Tomcat:

We are assuming you already know how to configure Tomcat clustering and session persistence on Tomcat.

Tomcat

https://tomcat.apache.org/tomcat-8.5-doc/cluster-howto.html

For Jetty check below documentation.

https://wiki.eclipse.org/Jetty/Tutorial/Session_Clustering

Edit the application xml under Catalina/localhost: i.e. dwp.xml, social.xml and smartit.xml and add this tag redistributable=true

distributable="true"

Restart Tomcat after these changes.

NOTE: Attached are some config files as an example.

This is where you find them
<Tomcat8.5>/conf/Catalina/localhost/dwp.xml
<Tomcat8.5>/conf/server.xml

HA Proxy config files are attached to this KA. You could use as a Protocol, but our recommendation is to use HTTP protocol for this purpose.

Configure HA Proxy
Restart HA proxy every time you do a config change by running

vi /etc/haproxy/haproxy.cfg        -- to update the configuration
sudo service haproxy restart     -- to restart the service
sudo service haproxy status -l   -- to make sure service is running properly

After this, HaProxy should work as expected.
Make sure you have enabled all the ports and configured your system/network security to allow this, as environments are very different, we would recommend checking your configuration with your security team: ports,firewall,acl, ssl, certificates, etc.
If you have Citrix NetScaler in place, make sure to enable session persistence on that end as well.

Attachment(s):

Config Files.zip