Using the Workload Manager Graphical Interface (gptop)

The Workload Manager Graphical interface, gptop, is a curses interface that you can use to monitor live data for the rules engine, host statistics, active Greenplum Database queries, and database skew.

You can start gptop from the command line by running gptop in a terminal. If you are already using interactive gp-wlm, enter the gptop command to enter the monitor.

Note: If you use the PuTTY ssh/telnet client for Windows to run gptop, you may experience problems with function keys and line-drawing characters with the default settings. To support function keys, in the PuTTY Configuration window, choose Connection > Data and enter xterm-color or putty in the Terminal-type string field. To enable correct line-drawing characters, choose Window > Translation and set Remote character set to Use font encoding.

When you first start gptop, the GPDB Queries pane (see below) is selected. At any time, you can press the F2 key to get a pane selection menu. Use the Tab, Left-Arrow, or Right-Arrow keys to make a selection. Press F2 to close an open menu without making a selection.

An asterisk (*) next to a column heading indicates that the rows are sorted by that column. To change the sort order, press the F3 key, then choose the number of the column you want to sort by from the pop-up menu.

Press q or choose File > Exit to leave gptop.

The gptop monitoring features are under the Monitor menu. The Monitor menu has four options:

  • GPDB Queries – Shows active Greenplum Database queries
  • GPDB Skew – Shows skew statics for active queries
  • Hydra – Shows statistics from the rules engine
  • SysData – Shows performance statistics for each host in the cluster

GPDB Queries

The GPDB Queries monitor displays a line for each active Greenplum Database query.

SessID
The session id for the query.

Time
The number of seconds since the query began executing.

User
The name of the Greenplum Database role that submitted the query.

ClientAddr
The network address from which the query was submitted.

DatName
The database name the query is running against.

Query
The text of the query.

GPDB Skew

The GPDB Skew monitor shows calculated skew statistics for active Greenplum Database queries. Statistics are calculated on each host in the system and then sent to the master where they are summarized. You can select a host and press Enter to see statistics for the host. The calculated skew value is the cubed standard deviation across the cluster. Values closer to 0.0 indicate less skew. The GPDB Skew monitor shows the following columns for each active query:

SessID
The Greenplum Database session ID for the query.

Time
The number of seconds since the query started.

User
The Greenplum Database role that submitted the query.

CPU-Skew
A measure of CPU skew calculated as the cubed standard deviation of the total CPU for each host for the query.

MEM-Skew
A measure of memory skew calculated as the cubed standard deviation of the total resident size percent for each host for the query.

READ-Skew
A measure of disk read I/O skew calculated as the cubed standard deviation of the bytes read per second for each host for the query.

WRITE-Skew
A measure of disk write I/O skew calculated as the cubed standard deviation of the bytes written per second for each host for the query.