Configuring the Node.js agent

You must add an agent data collector to your Node.js application and restart it before the agent can start monitoring your application.

1. Make sure that the user ID that is used to run the application server has full permission to the install_dir directory of the agent.
2. Go to the directory install_dir/bin and run the following command:

   ./nodejs-agent.sh config

3. Follow the prompts to specify values for the following configuration options:

   KNJ_NODEJS_RUNTIME_BIN_LOCATION

   The directory to the bin folder of your Node.js runtime. The default directory is /usr/local/bin.

   KNJ_NPM_RUNTIME_BIN_LOCATION

   The directory to the bin folder of you npm command. The default directory is /usr/local/bin.

   KNJ_NPM_LIB_LOCATION

   The directory to the lib folder of your npm package global installation directory. The default directory is /usr/local/lib. For example, if you install npm package by running npm install -g command, the package is installed to /nodejs_home/lib/node_modules and the KNJ_NPM_LIB_LOCATION is /nodejs_home/lib.

   CP_PORT

   The port that the agent listens on for data from socket clients. A value of 0 indicates that an ephemeral port will be used. The default value is 63336.

   Note: Don't use the port number that is already used in your system. To check whether the port is already in use, run the netstat -apn | grep port_number command.

4. Start the agent by running the following command:

   ./nodejs-agent.sh start

5. Verify that the Node.js agent is started successfully. The KNJ_NPM_LIB_LOCATION/node_modules/ibmapm folder is generated if the agent starts successfully.
6. Based on the offering that you have and your requirements, insert one of the following entries to the .js file of your Node.js application to configure the agent data collectors:
   Note: Only one entry can be added to your Node.js application to enable agent data collector capabilities. Also, if you enable capabilities that are not included in the offering, unnecessary overhead can happen, which decreases application execution efficiency.
   • If you have only resource monitoring capabilities, you can add the resource data collector. To add it, insert the following line in the beginning of the Node.js application file:

     require('KNJ_NPM_LIB_LOCATION/node_modules/ibmapm');

     If the value of KNJ_NPM_LIB_LOCATION on your environment is /usr/local/lib, the line is

     require('/usr/local/lib/node_modules/ibmapm');

   • If you have diagnostics in addition to resource-level monitoring capabilities, you can choose to add one of the following agent data collectors:
     • To add the method trace data collector, insert the following line in the beginning of the Node.js application file:

       require('KNJ_NPM_LIB_LOCATION/node_modules/ibmapm/methodtrace.js');

     • To add the diagnostics data collector, insert the following line in the beginning of the Node.js application file:

       require('KNJ_NPM_LIB_LOCATION/node_modules/ibmapm/deepdive.js');

     • To add the resource monitoring data collector, insert the following line in the beginning of the Node.js application file:

       require('KNJ_NPM_LIB_LOCATION/node_modules/ibmapm');

     To guarantee best performance, add the method trace data collector only for debugging purposes.

   Note: The code of the plug-ins changes from Cloud APM, Private V8.1.4. If you upgrade your agent from earlier versions, you must update the code of the existing data collectors in your applications for the monitoring ability to work properly.
7. Restart your Node.js application to enable the agent data collector.