Running the xgtd server

The server component of the xGT application is called xgtd. It is a daemon process launched automatically at boot. You can examine and control the xGT server using standard linux utilities:

sudo systemctl status xgtd
sudo systemctl stop xgtd
sudo systemctl start xgtd
sudo systemctl restart xgtd


When running xgtd using the using the strategy described above, the events are written into a log file named /var/log/xgtd.log.

Data considerations

When using the xgtd:// protocol for reading and writing data, xGT will look for relative pathnames in the /srv/xgtd/data directory. For example, xGT would look for the path xgtd://folder/file in /srv/xgtd/data/folder/file.

To learn more about loading and saving, read the data management guide.

Configuring xgtd

Some parameters of xGT can be configured with a JSON-formatted configuration file xgtd.conf located in the computer where the user is running the server process.

The folowing variables for configuring xGT are supported:

Example xgtd.conf file:

  "worker_threads" : 4,
  "pin_threads" : false,

To configure xGT on AWS, login to the server and create the file /etc/xgtd.conf or the file /home/xgtd/.xgtd.conf. The system will first look for the file /home/xgtd/.xgtd.conf, and if unsuccessful, it will look for the file /etc/xgtd.conf.

Then you would restart the xGT server:

sudo systemctl restart xgtd

S3 credentials

When loading a file using the load method and an s3: protocol prefix, xGT will check the /home/xgtd/.aws/credentials file for the two variables aws_access_key_id and aws_secret_access_key. The online AWS Access Keys document explains what these keys are and contains references to learn how to create and manage them. (These values may also be specified at runtime in user code by passing them to a Connection object.)

When reading the /home/xgtd/.aws/credentials file, xGT also supports profile selection via the AWS_PROFILE environment variable. If no environment variable is found, xGT will use the default profile.

Using an SSL secure channel

By default xGT uses an insecure channel, but an admin can enable a secure channel using SSL certifcates. To run a secure server, pass the flags -s (or --ssl) and -d (or --ssl_root_dir) when starting the xgtd executable. The ssl_root_dir argument should be the path to the root directory that holds the server's SSL certificates and private keys. xGT expects the following directory structure:

├── certs
│   ├── ca-chain.cert.pem
│   └── server.cert.pem
└── private
    └── server.key.pem

To connect to an xGT server using SSL, the client needs to pass the following flags to the xgt.Connection() method: ssl, ssl_root_dir, and ssl_server_cn. The ssl flag needs to be set to true. The ssl_root_dir flag should be set to the root directory containing the SSL certificates and private keys. The ssl_server_cn flag should be set to the common name for the server listed on the server side SSL certificate. The xGT client expects the following directory structure for SSL certificates and private keys:

├── certs
│   ├── ca-chain.cert.pem
│   └── client.cert.pem
└── private
    └── client.key.pem