Stresser

The Stresser application will publish a fixed amount of metrics to the carbon-cache regularly. It uses the Coda Hale metrics library internally and more specifically, it uses a Timer object to collect data. The Stresser receives a couple of parameters:

• Graphite host: in our case, the server housing our carbon cache
• Graphite port: in our case, the carbon cache port
• Number of hosts: to simulate publishing from
• Number of timers: each timer generates 15 distinct metrics
• Publishing interval
• Debug mode: true/false - logs the metrics that are published

You can run the Stresser using the following command:

Usage:

java -jar graphite-stresser.jar host port numHosts numTimers interval debug

	host: the Graphite endpoint
	port: the Graphite port
	numHosts: the number of hosts to simulate publishing from
	numTimers: the number of timers to create (options: [1, 2, 3, 4, 5, 10, 20, 64, 128, 256, 384, 650, 975, 1956, 3912, 4887, 7824, 9780, 13699])
	interval: the metric publishing interval (i.e. 10 seconds)
	debug: true/false to enable/disable debug mode

$ java -jar graphite-stresser.jar localhost 2003 1 128 10 true
Initializing 128 timers - publishing 1920 metrics every 10 seconds from 1 host(s)
Publishing metric: STRESS.host.ip-0.com.graphite.stresser.a
Publishing metric: STRESS.host.ip-0.com.graphite.stresser.ab
Publishing metric: STRESS.host.ip-0.com.graphite.stresser.abc
Publishing metric: STRESS.host.ip-0.com.graphite.stresser.abcd
...

The Coda Hale metrics library generates 15 distinct metrics per timer:

#ls -l /opt/graphite/storage/whisper/STRESS/host/ip-0/com/graphite/stresser/feg/
total 300
-rw-r--r--. 1 root root 17308 Jun  4 11:22 count.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 m15_rate.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 m1_rate.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 m5_rate.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 max.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 mean_rate.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 mean.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 min.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 p50.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 p75.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 p95.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 p98.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 p999.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 p99.wsp
-rw-r--r--. 1 root root 17308 Jun  4 11:22 stddev.wsp

Simulate Multiple Hosts

If you need to simulate reporting the same set of metrics from different hosts, you can modify the numHosts parameter. In this example, the application will initialize 10 timers are report the metrics from 5 different hosts:

$ java -jar graphite-stresser.jar localhost 2003 5 10 10 true
Initializing 10 timers - publishing 750 metrics every 10 seconds from 5 host(s)
Publishing metric: STRESS.host.ip-0.com.graphite.stresser.a
Publishing metric: STRESS.host.ip-1.com.graphite.stresser.a
Publishing metric: STRESS.host.ip-2.com.graphite.stresser.a
Publishing metric: STRESS.host.ip-3.com.graphite.stresser.a
Publishing metric: STRESS.host.ip-4.com.graphite.stresser.a
Publishing metric: STRESS.host.ip-0.com.graphite.stresser.b
Publishing metric: STRESS.host.ip-1.com.graphite.stresser.b
Publishing metric: STRESS.host.ip-2.com.graphite.stresser.b
Publishing metric: STRESS.host.ip-3.com.graphite.stresser.b
Publishing metric: STRESS.host.ip-4.com.graphite.stresser.b
...

Building

Building the jar is done through Gradle:

$ gradle uberjar

The built executable jar is now located at build/libs

This is tested with gradle 8.3 and OpenJDK 21

More Information

See the Stress Testing Carbon Caches blog post for more details.