Description:
And you have symptoms like this;
The Analysis page on the collector is hanging (update circle running) and showing error;
"Could not open database connection. Error in SqlCommand at Execute:"
On the SA Admin page the collector status is stopped and it cannot be started (action failed).
On the MTP Admin page under <Maintenance> - <Processes> You can see that all processes are stopped. When trying to start a message appears;
"Request to maintenance daemon failed. Make sure nqmaintd is running".
Try starting the /etc/init.d/nqmaintd and then see if can start all processes in the web GUI.
But then the database is not starting.
In <Administration> - <Maintenance> - <Database Status> there is an error
"Database usage not available because the database is down" and the DB "Metrics" has Status "UNKNOWN".
After a reboot the DB status is still in a state of "INITIALIZING".
Solution:
Sometimes it is necessary to drop and recreate the DB.
If you have any doubts at all about the state of your MTP database please raise a case with CA support. However, if you feel your status is as above, proceed.
You may have to drop the database manually and ensure ALL Vertica processes are stopped before starting up a new installation
When it calls for manually killing the processes use the command kill -9 <pid>
The following section gives additional troubleshooting information if the steps above to recreate the vertica database are not successful.
The steps above should work successfully to drop and recreate the vertica database.
If in doubt about the status of your MTP, please raise a support case before considering the recreate steps.