Why is it that when the database has an issue, it is mostly because of load or multiple queries or long running queries?
You can collect all of the following information and send it to NuoDB Support Team for analysis:
Check whether there are specific hours of the day that you have more load, at this range of time, we can we check periodically the number of connections, by:
SELECT count(*) from system.connections;
We can check which queries ran longer than 60 seconds since the last restart:
SELECT SQLSTRING from System.querystats Where RUNTIME>60000000;
Collect the output from the Linux “top” command.
You should create a diagnose, by:
/opt/nuodb/bin/nuodbmgr --broker localhost --password <password> --command "diagnose domain outdir <output_dir> fullcore true"
Monitor memory usage using the “monitor … “ command
- nuodbmgr --command “monitor …”
The NuoDB metric “Memory” shows the amount of memory taken by a nuodb engine (TE or SM) process:
- nuodbmgr --command “monitor domain” | grep Memory
The NuoDB metric “HeapActive” shows the size of the internal cache heap:
- nuodbmgr --command “monitor domain” | grep HeapActive