Environment Variables

The PTK reads the values of some specific environment variables that affect the runtime logic.

You can use the ptk env command to view all the environment variables supported by PTK and the corresponding values in effect.

If you want to see the value of a specific environment variable, you can use the ptk env <KEY> command, for example:

View the catalog of PTK metadata

ptk env PTK_HOME

List of supported environment variables

PTK reads the environment variables in the table below during runtime. You can change the behavior of PTK by modifying the environment variables with export.

Environment Variable Name	Description	Note
`PTK_HOME`	The root directory where PTK stores metadata, by default `$HOME/.ptk`.
`PTK_DATA_DIR`	The directory where PTK stores cluster metadata, by default `$PTK_HOME/data`.
`PTK_SSH_CONNECT_TIMEOUT`	The timeout for the executor to establish an SSH link with the target server, default is 1 minute.	In h(hour)/m(minute)/s(second), e.g. “2m20s”.
`PTK_CMD_EXECUTE_TIMEOUT`	Timeout for the executor to wait for a return from executing shell commands, default 10 minutes.	In h(hour)/m(minute)/s(second), e.g. “2m20s”.
`PTK_LOG_PATH`	The path to the file used to output the execution log. It can also be specified with the command line parameter `--log-file`. If this environment variable is set, it will be written to the log file in addition to the terminal output during the execution of PTK. By default, PTK itself will also record a log file in the `$PTK_HOME/log` directory during the runtime, which is not controlled by this environment variable.
`PTK_NO_CHECK_VERSION`	By default, PTK will check if there is a new version of PTK released when running a command. Set this environment variable to `true` to disable PTK version checking.
`PTK_NOT_LIMIT_CM_NODES`	PTK checks the number of CM nodes when deploying a MogDB database and deploying a CM cluster at the same time. when the number of CM nodes is greater than 3, by default, it forces to limit the deployment of only an odd number of CM server nodes to satisfy the majority election requirement, so when deploying a 4-node cluster, it will ask the user to select a node without deploying a CM server. the user can disable the restriction by setting the parameter to `true`. Of course, the same effect can also be achieved at installation time with the command line parameter `--not-limit-cm-nodes`.
`PTK_ENABLE_TIMEOUT_WHEN_BUILD_DB`	When PTK rebuilds a standby node with the `build` command, the timeout for executing the command is not set by default (i.e., `PTK_CMD_EXECUTE_TIMEOUT` does not take effect). This is because, in some high-volume data scenarios, executing a `build` can be very costly, and exiting after the timeout can result in the need to rebuild. If this parameter is set, `PTK_CMD_EXECUTE_TIMEOUT` will take effect.