Monitoring Greenplum Database Log Files

Know the location and content of system log files and monitor them on a regular basis and not just when problems arise.

The following table shows the locations of the various Greenplum Database log files. In file paths:

• $GPADMIN_HOME refers to the home directory of the gpadmin operating system user.
• $COORDINATOR_DATA_DIRECTORY refers to the coordinator data directory on the Greenplum Database coordinator host.
• $GPDATA_DIR refers to a data directory on the Greenplum Database segment host.
• host identifies the Greenplum Database segment host name.
• segprefix identifies the segment prefix.
• N identifies the segment instance number.
• date is a date in the format YYYYMMDD.

Path	Description
$GPADMIN_HOME/gpAdminLogs/*	Many different types of log files, directory on each server. $GPADMIN_HOME is the default location for the gpAdminLogs/ directory. You can specify a different location when you run an administrative utility command.
$GPADMIN_HOME/gpAdminLogs/gpinitsystem_date.log	system initialization log
$GPADMIN_HOME/gpAdminLogs/gpstart_date.log	start log
$GPADMIN_HOME/gpAdminLogs/gpstop_date.log	stop log
$GPADMIN_HOME/gpAdminLogs/gpsegstart.py_host:gpadmin_date.log	segment host start log
$GPADMIN_HOME/gpAdminLogs/gpsegstop.py_host:gpadmin_date.log	segment host stop log
$COORDINATOR_DATA_DIRECTORY/log/startup.log, $GPDATA_DIR/segprefixN/log/startup.log	segment instance start log
$COORDINATOR_DATA_DIRECTORY/log/*.csv, $GPDATA_DIR/segprefixN/log/*.csv	coordinator and segment database logs
$GPDATA_DIR/mirror/segprefixN/log/*.csv	mirror segment database logs
$GPDATA_DIR/primary/segprefixN/log/*.csv	primary segment database logs
/var/log/messages	Global Linux system messages

Note

If you manually set the server configuration parameter log_directory to specify a different directory for log files, the items on the table above whose path is under $COORDINATOR_DATA_DIRECTORY or $GPDATA_DIR should point to the value of log_directory instead. Note that when you specify the value as an absolute path, or as a relative path that is outside the data directory, Greenplum appends a subdirectory with a unique identifier (DBID) to the directory specified by this parameter. The unique identifier matches the value of dbid from gp_segment_configuration. For example, if you set log_directory as /tmp/logs, Greenplum creates the directories: /tmp/logs/1 for the coordinator, /tmp/logs/2 for seg0, /tmp/logs/3 for seg1, etcetera.

Use gplogfilter -t (--trouble) first to search the coordinator log for messages beginning with ERROR:, FATAL:, or PANIC:. Messages beginning with WARNING may also provide useful information.

To search log files on the segment hosts, use the Greenplum gplogfilter utility with gpssh to connect to segment hosts from the coordinator host. You can identify corresponding log entries in segment logs by the statement_id.

Greenplum Database can be configured to rotate database logs based on the size and/or age of the current log file. The log_rotation_size configuration parameter sets the size of an individual log file that triggers rotation. When the current log file size is equal to or greater than this size, the file is closed and a new log file is created. The log_rotation_age configuration parameter specifies the age of the current log file that triggers rotation. When the specified time has elapsed since the current log file was created, a new log file is created. The default log_rotation_age, 1d, creates a new log file 24 hours after the current log file was created.

Parent topic: System Monitoring and Maintenance