This tool traces busy processes associated with a Greenplum Database session. The information collected can be used by VMware Support for root cause analysis on hung sessions.
gpmt analyze_session [-session SESSION_ID ] [-master-dir DIRECTORY] [-segment-dir DIRECTORY]
- Greenplum session ID which is referenced in pg_stat_activity.
- Working directory for master process.
- Working directory for segment processes.
- Free space threshold which will exit log collection if reached. Default value is 10%.
- Answer Yes to all prompts.
Collect process information for a given Greenplum Database session id:
gpmt analyze_session -session 12345
The tool prompt gives a high-level list of only the servers that are running busy processes and how processes are distributed across the Greenplum hosts. This gives an idea of what hosts are busier than others, which might be caused by processing skew or other environmental issue with the affected hosts.
Note: lsof, strace, pstack, gcore, gdb must be installed on all hosts. gcore will perform a memory dump of the Greenplum process and the size could be anywhere from 300MB to several Gigabytes. Isolating which hosts to collect using the gpmtglobal option -hostfile to limit the collection size.