Verifying the load-balancing settings

Verifying the CNS load balancing tag

If you are in a load-balanced environment, you must verify the configuration file on each BMC Remedy Mid Tier server to include the <cns> tag. The value of this tag is the server name where this file resides. The default XML tag is <cns/>, which indicates that it is empty and has no value. In a load-balanced environment <cns> and </cns> include the server name in the tag.

For example, if you have three servers, S1, S2, and S3, each running a CNS, you might see the following values:

  • The value of this tag on Server 1 (S1) is <cns><portnumber>/eschat/rest/cns</cns>
  • The value of this tag on Server 2 (S2) is <cns><portnumber>/eschat/rest/cns</cns>
  • The value of this tag on Server 3(S3) is <cns><portnumber>/eschat/rest/cns</cns>


The server that you are verifying is the only server listed in the <cns> section. In earlier versions, all servers were entered in this section.

(For BMC Virtual Chat versions 9.1.01 and earlier) To verify the typing notification functionality

When the typing notification is accurately configured, the users and the support agents are aware that the other is typing a message in the Chat window.

In BMC Virtual Chat version 9.1.00, you must verify configuration in the file.

In BMC Virtual Chat version 9.1.01, you must verify the configuration in the file. 

  1. On each of the BMC Remedy Mid Tier server in your load-balanced environment, open the copy of the configuration file with any standard editor.
  2. Verify the value of the <cnslb> </cnslb> tag with the addresses of all the BMC Remedy Mid Tier servers in your load-balanced environment, excluding your current BMC Remedy Mid Tier server. The addresses should be separated by a semicolon. 
    For example, if you configure, you get the following value:
  3. If you made changes, you must restart Apache Tomcat.
    You can optionally wait to restart Apache Tomcat until you complete all configuration file changes.
  4. If you made changes, copy the configuration file to all the other BMC Remedy Mid Tier servers in your load-balanced environment.

(For BMC Virtual Chat version 9.1.02) To verify the typing notification functionality

In BMC Virtual Chat version 9.1.02, you must verify that the cnslb setting in the file is blank because the typing notification function is no longer using this parameter.

After installing, in the file, check whether the cnslb parameter contains a value (names of all the Mid Tier servers in the system). If it contains a value, then delete it so that the configuration is <cnslb></cnslb>.

After configuring, if the typing notifications are not working, enable the CNS Proxy Pass feature in the Chat Admin Console. For more information, see Enabling CNS Proxy Pass.

To update Virtual Agent queries

For some Virtual Agent queries, you must modify the URL field to use the BMC Remedy Mid Tier. For load-balance environments, replace [SERVER] with the virtual IP (VIP) or DNS name of the BMC Remedy Mid Tier load balancer.

  1. From the Virtual Agent  Administration Console, select General Settings >Virtual Agent Queries.
  2. Double click the ESChat Connection Config - Default Override item in the query list.
  3. Set correct values in <port> and <server> elements in URL field.
    The <server> element must contain name of the Load Balancing server.
    The following code is an example of the ESChat Connection Config - Default Override item:

    	<server><mid tier server or load balancer server for mid tier servers></server>
  4. Select Enabled radio button
  5. Click OK.

Related topics

System requirements
Enabling CNS Proxy Pass 

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  1. Jocelyn Arcega

    After spending some time reviewing the install and config instructions I am not entirely sure of the expected load-balancer set-up. My understanding is that there is no additional load-balancer configuration required, the existing load-balancer for ARS (tcp port chosen) and Mid-tier (https) will suffice. Can you confirm? Or is there a requirement to load-balance any of the CNS communication over port 6226?

    Jan 10, 2017 05:42
    1. Aaditi Lakade

      Hi Jocelyn, 

      Please give me a few days to confirm and get back to you.



      Jan 10, 2017 09:33
  2. Aaditi Lakade

    Hello Jocelyn, 

    The most important requirement to load-balance any of the CNS communication over port 6226 is to open the port in both directions between BMC Remedy AR System Server and BMC Remedy Mid Tier servers – and on Load Balancer too. For details, see "Open ports 6225 and 6226" section in the System requirements topic. 

    I have also updated this topic with these details. 


    Jan 12, 2017 10:46
    1. Jocelyn Arcega

      Hi Aaditi,

      I am still confused with the instructions. The section "Updating Virtual Agent queries" mentions Midtier server name in its description and then ar server name in the XML capture, which is it? If this is indeed configuration for Midtier value is there any place that hold value of the application load-balancer when used by the CNS servlet? I have a hard time understanding how the CNS Servlet (Midtier) and the CNS plugin (ARS) communicate over port 6225 and 6226 in a load-balanced environment, and if it requires a hardware load-balancer at all.

      Jan 30, 2017 09:19
      1. Aaditi Lakade

        Hi Jocelyn,

        I understood your confusion. Do check this space in a few days for clarification.

        Feb 09, 2017 10:34
  3. Aaditi Lakade

    Hi Jocelyn, 

    I have corrected the XML example in the docs. Thanks for pointing it out. Following are a few points that will help in understanding how the CNS Servlet and the CNS plugin communicate over port 6225 and 6226:

    • The SupportBotPlugin that runs on BMC Remedy AR System Server uses the configuration for Eschat Connection Config - Default Override. 
    • The SupportBotPlugin (that runs on BMC Remedy AR System Server) tries to establish socket connection to eschat web application (that runs on BMC Remedy Mid Tier Server) over port 6226
    • Starting from BMC Virtual Chat 9.1.01, eschat webapp contains CNS servlet code.



    Feb 12, 2017 10:15
  4. Pierre louis Rollin

    Hello Aaditi,

    can we have multiple livechat mid-tiers without LB and if so, how do we configure them ?

    Thanks in advance.

    Regards, Pierre.

    Dec 31, 2018 04:07
  5. Aaditi Lakade

    Hi Pierre, 

    Thanks for your query. I'll check with the R&D team and get back to you in a few days. 



    Dec 31, 2018 04:19
    1. Aaditi Lakade

      Hi Pierre, 

      Having multiple live chat mid-tiers without load balancer is an unsupported scenario. However, you can contact BMC support to try on your environment.



      Jan 06, 2019 09:54