ARTICLE

How to test the WebSocket connection with the Infrastructure testclient tool

February 07,2018

Wasin Waeosri

Overview

Update: March 2025.

Real-Time Websocket API (aka Websocket API) enables easy integration into a multitude of client technology environments such as scripting and web. This API runs directly on your Real-Time Distribution System (RTDS) and presents data in an open (JSON) readable format. The API supports all Real-Time data models and can be integrated into multiple client technology standards e.g. JavaScript, Python, R, .Net, etc.

The testclient tool (formerly known as rmdstestclient) is a general-purpose Real-Time consumer application. Its basic functionality is to load a list of RICs from file and request data of them from the Real-Time Interactive Provider sources like the Real-Time Advanced Distribution Server (ADS), EMA IProvider server, and Real-Time SDK OMM Provider.

This article shows how to use the testclient tool to verify and test the Real-Time Advanced Distribution Server (ADS) WebSocket connection and subscription.

*Note: This article is for deployed ADS customers only. If you are the Real-Time -- Optimized (RTO) user, please check the Testing RTO Connection with the TestClient Tool article.

WebSocket Overview

WebSocket specification defines an API that enables web pages to use the WebSockets protocol for two-way communication with a remote host. It introduces the WebSocket interface and defines a full-duplex communication channel that operates through a single socket over the Web. This specification was also later applied to other client technology sides like Python, Ruby, Go, Java, etc.

Figure-1: WebSocket connection diagram

testclient tool Overview

The testclient is part of the Infrastructure Tools (aka Real-Time Distribution System Demo tools). You can download the tools package from the Developer Portal and https://myaccount.lseg.com websites. The testclient tool is also bundled with Real-Time Advanced Distribution Server package (available at <Real-Time Advanced Distribution Server package>/<platform>/demo folder) too. It supports various Real-Time Advanced Distribution Server connection types (RSSL, WebSocket, etc), various Real-Time Data Domain data (Market Price, Market By Price, Market By Order, etc). This tool is perfect for verifying the Real-Time Advanced Distribution Server connection and subscription

Figure-2: Infra Tools demo folder structure

Figure-3: Real-Time Advanced Distribution Server 3.2 demo folder structure

Basic testclient arguments and how to run the tool

You can run the testclient tool via the following steps

Goto <Real-Time Advanced Distribution Server package>/<platform>/demo or <Infrastructure Tools>/<platform>/demo folder via the command line (from Linux terminal or any SSH applications)
Export LD_LIBRARY_PATH to <Real-Time Advanced Distribution Server package>/<platform>/demo location via the following command

    	
            $>export LD_LIBRARY_PATH=<Real-Time Advanced Distribution Server package>/<platform>/demo

    	
            $>export LD_LIBRARY_PATH=<Infrastructure Tools>/<platform>/demo

3. Create the item.txt file, then input the RIC name in each line

    	
            FB.O
VOD.L
PTT.BK

4. Run the testclient tool via the following command

    	
            $> ./testclient -S <Service name> -h <Real-Time Advanced Distribution Server IP Address or Hostname> -ct <Connection type> -p <WebSocket port> -l stdout -X -f item.txt -v -d 3 –Z –md <domain> –u <username>

You can run it with just ./testlcient command to get information of all command-line arguments that you can set with the tool

Figure-4: testclient manual

How to connect testclient with WebSocket connection

Users can use -ct ws_json2 -dfile <RDMFieldDictionary file> -p <WebSocket port> parameters to connect testclient with Real-Time Advanced Distribution Server WebSocket connection.

-ct ws_json2 parameter means to specify the tool to connect to Real-Time Advanced Distribution Server via the WebSocket connection
-dfile <RDMFieldDictionary file> is a required parameter when connecting via WebSocket connection . This parameter specifies the Real-Time's Data Dictionary RDMFieldDictionary file for testclient tool.
-p <WebSocket port> specifies the Real-Time Advanced Distribution Server WebSocket port (this port can be configured in ADS configurations *ads*wsPort parameter)

Example command

    	
            $> ./testclient -h 172.20.33.11 -p 15000 -S ELEKTRON_DD -ct ws_json2  -dfile ./RDMFieldDictionary -l stdout -X -f item.txt -v -d 3 –Z –md 6 –u api

Result