How to Run gpcheckperf for Disk and Network Performance Test

Products

• VMware Tanzu Greenplum

Issue/Introduction

gpcheckperf is a Greenplum support utility designed to help identify possible system-level issues with a Greenplum database cluster. 

This article discusses how to run gpcheckperf for disk and network performance test.

 

 

Environment

Resolution

The gpcheckperf utility starts a session on the specified hosts and can run the following performance tests:

• Netperf Test: Runs a netperf TCP_STREAM test, which transfers a 15-second stream of data between the hosts included in the test.
• Disk I/O Test (dd test): Tests the sequential throughput performance of a logical disk or file system.
• Memory Bandwidth Test (stream test): Tests the memory bandwidth, the utility uses the STREAM benchmark program to measure sustainable memory bandwidth (in MB s).

Network performance (netperf) test

Here is the configuration for this example:

Master = mdw1-1 mdw1-2 mdw1-3 mdw1-4
Segment 1 = sdw1-1 sdw1-2 sdw1-3 sdw1-4
Segment 2 = sdw2-1 sdw2-2 sdw2-3 sdw2-4
Segment 3 = sdw3-1 sdw3-2 sdw3-3 sdw3-4

Create a hostfile for each subnet:

cat host_file_nic_1
mdw1-1
sdw1-1
sdw2-1
sdw3-1

cat host_file_nic_2
mdw1-2
sdw1-2
sdw2-2
sdw3-2

cat host_file_nic_3
mdw1-3
sdw1-3
sdw2-3
sdw3-3

cat host_file_nic_4
mdw1-4
sdw1-4
sdw2-4
sdw3-4

Execute the test issue using the below command:

gpcheckperf -f host_file_nic_1 -r N -d /tmp > host_file_nic_1.out
gpcheckperf -f host_file_nic_2 -r N -d /tmp > host_file_nic_2.out
gpcheckperf -f host_file_nic_3 -r N -d /tmp > host_file_nic_3.out
gpcheckperf -f host_file_nic_4 -r N -d /tmp > host_file_nic_4.out

Run on specified nics:

gpcheckperf -h sdw1-2 -h sdw4-2 -r N -d /tmp >sdw1-2andsdw4-2.out
gpcheckperf -h sdw1-3 -h sdw4-3 -r N -d /tmp > sdw1-3andsdw4-3.out

Disk I/O test and memory bandwidth test

Note- Do not include the master host in this test.

gpcheckperf -f host_file_nic_1 -r ds -D -d /data/gpdb_p1 -d  /data/gpdb_p2 -d /data/gpdb_p3 -d  /data/gpdb_p4 -d /data/gpdb_m1 -d  /data/gpdb_m2 -d /data/gpdb_m3 -d  /data/gpdb_m4

You only need to run this test once with a host file that includes all segment host members.

 

Additional Information

• Ensure that the host file contains an even number of hosts, as having an odd number of servers in the hostile results in one server having the lower number than the rest, due to two server using that host to communicate to test the speed.
• It is always best to have the server in IDLE (database, application etc stopped) state; so that the test result is valid and servers do not show variation in test results.

+ Environment:

Pivotal Greenplum Database (GPDB) all versions