gs_checkperf
Background
openGauss provides the gs_checkperf tool for you to routinely check the openGauss-level performance (such as host CPU, Gauss GPU, and I/O usage), host-level performance (CPU, memory, and I/O usage), session-/process-level performance (CPU, memory, and I/O usage), and SSD performance (write and read performance). This helps you learn the openGauss load and fine-tune database performance accordingly.
Prerequisites
- openGauss running status is normal and is not the read-only mode.
- Services are running properly on the database.
Precautions
The monitoring information of gs_checkperf comes from tables in PMK mode. If the ANALYZE operation is not performed on such tables, gs_checkperf may fail to be executed. An example of the error information is as follows:
LOG: Statistics in some tables or columns(pmk.pmk_snapshot.snapshot_id) are not collected. HINT: Do analyze for them in order to generate optimized plan.To fix this error, log in to a node where a master database node is deployed, connect to the postgres database, and run the following SQL statements:
analyze pmk.pmk_configuration; analyze pmk.pmk_meta_data; analyze pmk.pmk_snapshot; analyze pmk.pmk_snapshot_dbnode_stat; analyze pmk.pmk_snapshot_datanode_stat;
Syntax
Check the SSD performance (as user root).
gs_checkperf -U USER [-o OUTPUT] -i SSD [-l LOGFILE]Check the openGauss performance (as the user for installing openGauss).
gs_checkperf [-U USER] [-o OUTPUT] [-i PMK] [--detail] [-l LOGFILE]Display help information.
gs_checkperf -? | --helpDisplay version information.
gs_checkperf -V | --version
Parameter Description
-U
Specifies the name of the user for running openGauss.
Value range: name of the user for running openGauss
Specify this parameter when you run the command as user root.
-o
Specifies the file for saving performance check reports.
Value range: the name of a specified file
If this parameter is not specified, OS check results are displayed on the screen.
-i
Specifies the number of a check item. This parameter is case-insensitive. Format: -i PMK and -i SSD
Value range: PMK and SSD
Check the PMK item as an openGauss user.
Check the SSD item as user root.
If this parameter is not specified, the PMK item is checked by default as the openGauss user, and SSD item is checked by default as user root.
--detail
Displays detailed PMK check results.
-l
Specifies the path for saving log files.
The default path is /var/log/gaussdb/omm/om/gs_checkperf-YYYY-MM-DD_hhmmss.log.
-?, --help
Displays help information.
-V, --version
Displays version information.
Table 1 Performance check items
Examples
Example 1: Run the following command to display performance statistics in simple mode on the screen:
gs_checkperf -i pmk -U omm
Cluster statistics information:
Host CPU busy time ratio : 1.43 %
GaussDB CPU time % in busy time : 1.88 %
Shared Buffer Hit ratio : 99.96 %
In-memory sort ratio : 100.00 %
Physical Reads : 4
Physical Writes : 25
DB size : 70 MB
Total Physical writes : 25
Active SQL count : 2
Session count : 3
Example 2: Run the following command to display performance statistics in detailed mode on the screen:
gs_checkperf -i pmk -U omm --detail
Cluster statistics information:
Host CPU usage rate:
Host total CPU time : 42386.667 Jiffies
Host CPU busy time : 1873.333 Jiffies
Host CPU iowait time : 20.000 Jiffies
Host CPU busy time ratio : 4.42 %
Host CPU iowait time ratio : .05 %
GaussDB CPU usage rate:
GaussDB CPU time % in busy time : 19.04 %
GaussDB CPU time % in total time : .84 %
Shared buffer hit rate:
Shared Buffer Reads : 0
Shared Buffer Hits : 24129
Shared Buffer Hit ratio : 100.00 % In-memory sort ratio : 100.00 %I/O usage:
Number of files : 537
Physical Reads : 0
Physical Writes : 0
Read Time : 0 ms
Write Time : 0 ms
Disk usage:
DB size : 70 MB
Total Physical writes : 0
Average Physical write : 0
Maximum Physical write : 0
Activity statistics:
Active SQL count : 2
Session count : 3
Node statistics information:
dn_6001_6002:
GaussDB CPU Time : 200 Jiffies
Host CPU Busy Time : 3490 Jiffies
Host CPU Total Time : 42330 Jiffies
GaussDB CPU Time % in Busy Time : 5.73 %
GaussDB CPU Time % in Total Time : .47 %
Physical memory : 8231776256 Bytes
DB Memory usage : 877236224 Bytes
Shared buffer size : 33554432 Bytes
Shared buffer hit ratio : 100.00 %
Sorts in memory : 123
Sorts in disk : 0
In-memory sort ratio : 100.00 %
Number of files : 149
Physical Reads : 0
Physical Writes : 0
Read Time : 0
Write Time : 0
dn_6003_6004:
GaussDB CPU Time : 170 Jiffies Host CPU Busy Time : 1030 Jiffies
Host CPU Total Time : 42470 Jiffies GaussDB CPU Time % in Busy Time : 16.50 %
GaussDB CPU Time % in Total Time : .40 %
Physical memory : 8231776256 Bytes
DB Memory usage : 881434624 Bytes Shared buffer size : 33554432 Bytes
Shared buffer hit ratio : 100.00 %
Sorts in memory : 119
Sorts in disk : 0
In-memory sort ratio : 100.00 %
Number of files : 165
Physical Reads : 0
Physical Writes : 0
Read Time : 0
Write Time : 0
dn_6005_6006:
GaussDB CPU Time : 220 Jiffies
Host CPU Busy Time : 1100 Jiffies
Host CPU Total Time : 42360 Jiffies
GaussDB CPU Time % in Busy Time : 20.00 %
GaussDB CPU Time % in Total Time : .52 %
Physical memory : 8231776256 Bytes
DB Memory usage : 881430528 Bytes
Shared buffer size : 33554432 Bytes
Shared buffer hit ratio : 100.00 %
Sorts in memory : 122
Sorts in disk : 0
In-memory sort ratio : 100.00 %
Number of files : 115
Physical Reads : 0
Physical Writes : 0
Read Time : 0
Write Time : 0
Session statistics information(Top 10):
Session CPU statistics:
1 dn_6003_6004-postgres-dbazt:
Session CPU time : 1211
Database CPU time : 37670
Session CPU time % : 3.21 %
2 dn_6005_6006-postgres-dbazt:
Session CPU time : 1204
Database CPU time : 35730
Session CPU time % : 3.37 %
3 dn_6001_6002-postgres-dbazt:
Session CPU time : 1064
Database CPU time : 34120
Session CPU time % : 3.12 %
Session Memory statistics:
1 dn_6005_6006-postgres-dbazt:
Buffer Reads : 8989
Shared Buffer Hit ratio : 96.97
In Memory sorts : 136
In Disk sorts : 0
In Memory sorts ratio : 100.00
Total Memory Size : 21593048
Used Memory Size : 18496600
2 dn_6003_6004-postgres-dbazt:
Buffer Reads : 9030
Shared Buffer Hit ratio : 96.94
In Memory sorts : 133
In Disk sorts : 0
In Memory sorts ratio : 100.00
Total Memory Size : 21576664
Used Memory Size : 18495688
3 dn_6001_6002-postgres-dbazt:
Buffer Reads : 8668
Shared Buffer Hit ratio : 96.97
In Memory sorts : 138
In Disk sorts : 0
In Memory sorts ratio : 100.00
Total Memory Size : 21258856
Used Memory Size : 18159736
Session IO statistics:
1 dn_6003_6004-postgres-dbazt:
Physical Reads : 285
Read Time : 5320
2 dn_6005_6006-postgres-dbazt:
Physical Reads : 281
Read Time : 5811
3 dn_6001_6002-postgres-dbazt:
Physical Reads : 271
Read Time : 4662