gpmt analyze_session

This tool traces busy processes associated with a LightDB-A Database session. The information collected can be used by VMware Support for root cause analysis on hung sessions.

Usage

gpmt analyze_session [-session <session_id> ] [-master-dir <directory>] 
[-segment-dir <directory>] 

Options

-session : LightDB-A session ID which is referenced in pg_stat_activity.

-master-dir : Working directory for coordinator process.

-segment-dir : Working directory for segment processes.

-free-space : Free space threshold which will exit log collection if reached. Default value is 10%.

-a : Answer Yes to all prompts.

Examples

Collect process information for a given LightDB-A 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 LightDB-A 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 LightDB-A process and the size could be anywhere from 300MB to several Gigabytes. Isolating which hosts to collect using the gpmt global option -hostfile to limit the collection size.