All you need to know about network gateways for Workload Automation Dynamic Agent

What is a gateway? You can configure a Dynamic Agent as a network gateway to other Dynamic Agents which cannot communicate directly with the Dynamic Workload Broker (DWB) installed on the Master Domain Manager (MDM) or Domain Manager (DM).
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This article aims to explore the different types of gateway supported by Workload Automation Dynamic Agent. ​
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Workload Automation Dynamic Agent (DA) architecture supports two types of gateway: 

1. Local gateway 
2. Remote gateway 

 
Before installing a Dynamic Agent, you should know/decide whether to install it as local or remote gateway. Specify the parameter -gateway local|remote during the Dynamic Agent installation.  
 
However, you can reconfigure the Dynamic Agent as remote or local gateway after the installation modifying the JobManager.ini and/or JobManagerGW.ini depending on your requirement. 
 
Local Gateway 

• If your Dynamic Agent can directly communicate with the DWB installed on MDM or DM, then you can configure the Dynamic Agent as local gateway. However, you must specify the gateway type during the agent installation, by specifying the parameter -gateway local. 

• DWB communication parameters for a Dynamic Agent configured as local gateway are located in the following file:  <TWSHOME>/ITA/cpa/config/JobManagerGW.ini. 
• StartUpLwa command on the local gateway starts three processes: ITA agent, JobManager and JobManagerGW. 
• JobManager and JobManagerGW processes are spawned by the ITA agent process. 
• ITA agent process in a Dynamic Agent manages network communication with the workload broker service on MDM or DM.   
• JobManagerGW process collects the system resource information like OS, CPU utilisation, network and file system details in the Dynamic Agent then sends them to the resource advisor service on MDM or DM.   
• JobManager process spawned in the Dynamic Agent communicates with JobManagerGW locally and executes the actions through taskLauncher. 
• Communication logs to DWB from JobManagerGW are stored in the following file: <TWSHOME>/stdlist/JM/JobManagerGW_message.log 
• Communication logs to JobManagerGW from JobManager are stored in the following file: <TWSHOME>/stdlist/JM/JobManager_message.log  
• JobManagerGW process receives the actions to be execute on the agent from DWB through jmport specified during the installation. Port 31114 is the default jmport. 
• Gateway id GWID specified during the installation identifies the gateway site of the Dynamic Agent. Gateway id is associated only with local gateways. This value is customisable. GW1 is the default gateway id. 

 
Installation Command Example   
twsinst -new -uname <user_name> -password XXXXX -acceptlicense yes -agent dynamic  -gateway local  -gwid GW1  -jmport 31114  -hostname localgateway.mycompany.com -tdwbport 31116  -tdwbhostname mainbroker.mycompany.com 

Below diagram demonstrates the communication from local gateway to Dynamic Workload Broker.

Remote Gateway 

• If your Dynamic Agent cannot directly communicate with DWB installed on MDM or DM, then you can configure the Dynamic Agent as remote gateway. Dynamic Agent configured as remote gateway can communicate with DWB through another local gateway. You should specify the gateway type -gateway remote during the agent installation with -tdwbport and -tdwbhostname. 
• All the communication from a Dynamic Agent configured as remote gateway to DWB will go through the local gateway specified during the agent installation -tdwbhostname hostname and -tdwbport 31114. 

        - tdwbhostname hostname is the hostname of the Dynamic Agent which is
          configured as local gateway. Local gateway can establish the communication
          with DWB directly. 
        - tdwbport 31114 is the jmport of the Dynamic Agent which is configured
          as local gateway. 

• Local gateway communication parameters are configured in the following file: <TWSHOME>/ITA/cpa/config/JobManager.ini 
• StartUpLwa command on the Dynamic Agent configured as remote gateway starts two processes:  JobManager and ITA agent. 
• ITA agent process in remote gateway manages network communication with local gateway. 
• JobManager process collects the system resource information like OS, CPU utilisation, network and file system details in the remote gateway then sends them to local gateway, which in turn communicates with DWB on MDM or DM.  
• JobManager logs are stored in the following file: <TWSHOME>/stdlist/JM/JobManager_message.log 
• Gateway ID GWID is not associated with the Dynamic Agent configured as remote gateway. 

 
Installation Command Example  
twsinst -new -uname <user_name> -password XXXXX -acceptlicense yes -agent dynamic  -gateway remote -jmport 31117  -tdwbport 31114  -tdwbhostname localgateway.mycompany.com  
 
Below diagram demonstrates the communication from remote gateway to DWB through local gateway.

 Points to remember:

• Gateway agents are Operating System independent. You can configure UNIX DA(s) as network gateways for Windows DA(s) and vice versa 

• jmport 31114 initialised during StartUpLwa “listens to” the incoming request from DWB or remote gateway 
• jmport need not to be open bi-directional. Jmport just “listens to” incoming request from DWB or from remote gateway always
  
  

If you want to know more about local and remote gateways for Workload Automation Dynamic Agent, you can contact Madhusudan Raju madhusudan_r@hcl.com.

Madhusudan Raju 
Senior Technical Specialist

Madhusudan has been working on Workload Automation for 10+ years. He is currently engaged in WA solution on IBM SaaS, focusing mainly on advanced WA solutions through the DevOps delivery model. He is currently associated with HCL Technologies Product and Platform division as a Senior Technical Specialist.