Red Hat Summit Red Hat SummitApoyoConsolaDesarrolladoresIniciar una pruebaContacto

Este contenido no está disponible en el idioma seleccionado.

9.6. Using queue statistics

Functions with the qsq_ prefix query the statistics averaged since the first queue operation or when qsq_start was called. Since statistics are often fractional, a scale parameter multiplies the result to a more useful scale. For some fractions, a scale of 100 returns percentage numbers.

9.6.1. qsq_blocked
Copiar enlace

General syntax: 
qsq_blocked:long (qname:string, scale:long)
Copy to Clipboard Toggle word wrap
This function returns the fraction of elapsed time during which one or more requests were on the wait queue.

9.6.2. qsq_print
Copiar enlace

General syntax: 
qsq_print:unknown (qname:string)
Copy to Clipboard Toggle word wrap
This function prints a line containing the following statistics for the given queue:
  • queue name
  • average rate of requests per second
  • average wait queue length
  • average time on the wait queue
  • average time to service a request
  • percentage of time the wait queue was used
  • percentage of time any request was being serviced

9.6.3. qsq_service_time
Copiar enlace

General syntax: 
qsq_service_time:long (qname:string, scale:long)
Copy to Clipboard Toggle word wrap
This function returns the average time in microseconds required to service a request once it is removed from the wait queue.

9.6.4. qsq_start
Copiar enlace

General syntax: 
qsq_start:unknown (qname:string)
Copy to Clipboard Toggle word wrap
This function resets the statistics counters for the given queue, and restarts tracking from the moment the function was called. This command is used to create a queue.

9.6.5. qsq_throughput
Copiar enlace

General syntax: 
qsq_throughput:long (qname:string, scale:long)
Copy to Clipboard Toggle word wrap
This function returns the average number of requests served per microsecond.

9.6.6. qsq_utilization
Copiar enlace

General syntax: 
qsq_utilization:long (qname:string, scale:long)
Copy to Clipboard Toggle word wrap
This function returns the average time in microseconds that at least one request was being serviced.

9.6.7. qsq_wait_queue_length
Copiar enlace

General syntax: 
qsq_wait_queue_length:long (qname:string, scale:long)
Copy to Clipboard Toggle word wrap
This function returns the average length of the wait queue.

9.6.8. qsq_wait_time
Copiar enlace

General syntax: 
qsq_wait_time:long (qname:string, scale:long)
Copy to Clipboard Toggle word wrap
This function returns the average time in microseconds that it took for a request to be serviced (qs_wait() to qs_done()).

9.6.9. A queue example
Copiar enlace

What follows is an example from src/testsuite/systemtap.samples/queue_demo.stp. It uses the randomize feature of the timer probe to simulate queuing activity. 
probe begin {
qsq_start ("block-read")
qsq_start ("block-write")
}

probe timer.ms(3500), end {
qsq_print ("block-read")
qsq_start ("block-read")
qsq_print ("block-write")
qsq_start ("block-write")
}

probe timer.ms(10000) {
exit ()
}

# synthesize queue work/service using three randomized "threads" for each queue.
global tc

function qs_doit (thread, name) {
n = tc[thread] = (tc[thread]+1) % 3 # per-thread state counter
if (n==1) qs_wait (name)
else if (n==2) qs_run (name)
else if (n==0) qs_done (name)
}

probe timer.ms(100).randomize(100) { qs_doit (0, "block-read") }
probe timer.ms(100).randomize(100) { qs_doit (1, "block-read") }
probe timer.ms(100).randomize(100) { qs_doit (2, "block-read") }
probe timer.ms(100).randomize(100) { qs_doit (3, "block-write") }
probe timer.ms(100).randomize(100) { qs_doit (4, "block-write") }
probe timer.ms(100).randomize(100) { qs_doit (5, "block-write") }
Copy to Clipboard Toggle word wrap
This prints: 
block-read: 9 ops/s, 1.090 qlen, 215749 await, 96382 svctm, 69% wait, 64% util
block-write: 9 ops/s, 0.992 qlen, 208485 await, 103150 svctm, 69% wait, 61% util
block-read: 9 ops/s, 0.968 qlen, 197411 await, 97762 svctm, 63% wait, 63% util
block-write: 8 ops/s, 0.930 qlen, 202414 await, 93870 svctm, 60% wait, 56% util
block-read: 8 ops/s, 0.774 qlen, 192957 await, 99995 svctm, 58% wait, 62% util
block-write: 9 ops/s, 0.861 qlen, 193857 await, 101573 svctm, 56% wait, 64% util
Copy to Clipboard Toggle word wrap
Volver arriba
Red Hat logoGithubredditYoutubeTwitter

Aprender

Pruebe, compre y venda

Comunidades

Acerca de la documentación de Red Hat

Ayudamos a los usuarios de Red Hat a innovar y alcanzar sus objetivos con nuestros productos y servicios con contenido en el que pueden confiar. Explore nuestras recientes actualizaciones.

Hacer que el código abierto sea más inclusivo

Red Hat se compromete a reemplazar el lenguaje problemático en nuestro código, documentación y propiedades web. Para más detalles, consulte el Blog de Red Hat.

Acerca de Red Hat

Ofrecemos soluciones reforzadas que facilitan a las empresas trabajar en plataformas y entornos, desde el centro de datos central hasta el perímetro de la red.

Theme

© 2025 Red Hat