.. highlight:: bash =============== Troubleshooting =============== #. To troubleshoot problems with presto-admin or Presto, you can use the incident report gathering commands from presto-admin to gather logs and other system information from your cluster. Relevant commands: * :ref:`collect-logs` * :ref:`collect-query-info` * :ref:`collect-system-info` #. You can find the ``presto-admin`` logs in the ``~/.prestoadmin/log`` directory. #. You can check the status of Presto on your cluster by using :ref:`server-status`. #. If Presto is not running and you try to execute any command from the Presto CLI you might get: :: $ Error running command: Server refused connection: http://localhost:8080/v1/statement To fix this, start Presto with: :: $ ./presto-admin server start #. If the Presto servers fail to start or crash soon after starting, look at the presto server logs on the Presto cluster ``/var/log/presto`` for an error message. You can collect the logs locally using :ref:`collect-logs`. The relevant error messages should be at the end of the log with the most recent timestamp. Below are tips for some common errors: * Specifying a port that is already in use: Look at :ref:`presto-port-configuration-label` to learn how to change the port configuration. * An error in a catalog configuration file, such as a syntax error or a missing connector.name property: correct the file and deploy it to the cluster again using :ref:`catalog-add` #. The following error can occur if you do not have passwordless ssh enabled and have not provided a password or if the user requires a sudo password: :: Fatal error: Needed to prompt for a connection or sudo password (host: master), but input would be ambiguous in parallel mode See :ref:`ssh-configuration-label` for information on setting up passwordless ssh and on providing a password, and :ref:`sudo-password-spec` for information on providing a sudo password. #. Support for connecting to a cluster with internal HTTPS and/or LDAP communication enabled is experimental. Make sure to check both the Presto server log and the ``presto-admin`` log to troubleshoot problems with your configuration; it may also be helpful to verify that you can connect to the cluster via the Presto CLI using HTTPS/LDAP as appropriate.