Intense parallel workloads can be difficult to monitor. Packages crew.cluster
,
clustermq
,
and future.batchtools
distribute hundreds of worker processes over multiple computers. If a
worker process exhausts its available memory, it may terminate silently,
leaving the underlying problem difficult to detect or troubleshoot.
Using the autometric
package, a worker can proactively
monitor itself in a detached POSIX thread. The worker process itself
runs normally, and the thread writes to a log every few seconds. If the
worker terminates unexpectedly, autometric
can read and
visualize the log file to reveal potential resource-related reasons for
the crash.
You can install the development version of autometric
from GitHub with:
::install_github("wlandau/autometric") remotes
The log_start()
function in autometric
starts a non-blocking POSIX thread to write resource usage statistics to
a log at periodic intervals. The following example uses the callr
R package to
launch a resource-intensive background process on a Unix-like system.
The autometric
thread prints to standard output, and
callr
directs all its standard output to a temporary text
file we define in advance.1 Custom calls to
log_phase_set()
annotate the log data2.
<- tempfile()
log_file
<- callr::r_bg(
process func = function() {
library(autometric)
log_phase_set("setup")
log_start(
path = "/dev/stdout",
pids = c(my_worker = Sys.getpid()),
seconds = 1
)
log_phase_set("warmup")
Sys.sleep(3)
print("You can mix printed messages with regular log data.")
print("Defining a function that guzzles CPU power.")
<- function(n) {
is_prime if (n <= 1) return(FALSE)
for (i in seq(2, sqrt(n))) {
if (n %% i == 0) {
return(FALSE)
}
}TRUE
}
log_phase_set("large object")
<- rnorm(1e8)
x
log_phase_set("heavy cpu")
lapply(seq_len(1e6), is_prime)
log_phase_set("another object")
<- rnorm(1e8)
y
log_phase_set("more cpu")
lapply(seq_len(1e6), is_prime)
log_phase_set("third object")
<- rnorm(1e8)
z
log_phase_set("done")
},stdout = log_file
)
When we read in the log file, we see messages from both R and the
autometric
thread.
writeLines(readLines(log_file))
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312985.355|0.800|0.080|81707008|420736614400|warmup|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312986.360|0.000|0.000|81707008|420736614400|warmup|__AUTOMETRIC__
#> [1] "You can mix printed messages with regular log data."
#> [1] "Defining a function that guzzles CPU power."
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312987.361|0.000|0.000|81788928|420745003008|large object|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312988.367|98.200|9.820|384761856|421545033728|large object|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312989.372|99.300|9.930|551337984|421545033728|large object|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312990.377|99.100|9.910|505069568|421553422336|heavy cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312991.378|100.000|10.000|339132416|421561810944|heavy cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312992.380|99.300|9.930|332136448|421561810944|heavy cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312993.385|100.000|10.000|291848192|421561810944|heavy cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312994.390|100.000|10.000|272302080|421561810944|heavy cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312995.395|100.000|10.000|221003776|421561810944|heavy cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312996.400|100.000|10.000|154877952|421561810944|heavy cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312997.403|99.200|9.920|178995200|422361825280|another object|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312998.405|100.000|10.000|475480064|422361825280|another object|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730312999.410|99.500|9.950|733970432|422361825280|another object|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730313000.415|98.000|9.800|682590208|422361825280|more cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730313001.416|100.000|10.000|479789056|422361825280|more cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730313002.421|99.600|9.960|340885504|422361825280|more cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730313003.426|100.000|10.000|120291328|422361825280|more cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730313004.432|99.700|9.970|124502016|422361825280|more cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730313005.437|98.200|9.820|125583360|422361825280|more cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730313006.442|99.700|9.970|125386752|422361825280|more cpu|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730313007.444|98.200|9.820|261177344|423161839616|third object|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730313008.447|99.500|9.950|564985856|423161839616|third object|__AUTOMETRIC__
#> __AUTOMETRIC__|0.1.0|50454|my_worker|0|1730313009.452|100.000|10.000|602243072|423161839616|third object|__AUTOMETRIC__
autometric
knows how to read its log entries even if the
log file has other messages. See the documentation of
log_read()
to learn how to interpret the data and customize
the measurement units.
library(autometric)
<- log_read(log_file)
log_data
log_data#> version phase pid name status time core cpu resident
#> 1 0.1.0 warmup 50454 my_worker 0 0.000 0.8 0.08 81.70701
#> 2 0.1.0 warmup 50454 my_worker 0 1.005 0.0 0.00 81.70701
#> 3 0.1.0 large object 50454 my_worker 0 2.006 0.0 0.00 81.78893
#> 4 0.1.0 large object 50454 my_worker 0 3.012 98.2 9.82 384.76186
#> 5 0.1.0 large object 50454 my_worker 0 4.017 99.3 9.93 551.33798
#> 6 0.1.0 heavy cpu 50454 my_worker 0 5.022 99.1 9.91 505.06957
#> 7 0.1.0 heavy cpu 50454 my_worker 0 6.023 100.0 10.00 339.13242
#> 8 0.1.0 heavy cpu 50454 my_worker 0 7.025 99.3 9.93 332.13645
#> 9 0.1.0 heavy cpu 50454 my_worker 0 8.030 100.0 10.00 291.84819
#> 10 0.1.0 heavy cpu 50454 my_worker 0 9.035 100.0 10.00 272.30208
#> 11 0.1.0 heavy cpu 50454 my_worker 0 10.040 100.0 10.00 221.00378
#> 12 0.1.0 heavy cpu 50454 my_worker 0 11.045 100.0 10.00 154.87795
#> 13 0.1.0 another object 50454 my_worker 0 12.048 99.2 9.92 178.99520
#> 14 0.1.0 another object 50454 my_worker 0 13.050 100.0 10.00 475.48006
#> 15 0.1.0 another object 50454 my_worker 0 14.055 99.5 9.95 733.97043
#> 16 0.1.0 more cpu 50454 my_worker 0 15.060 98.0 9.80 682.59021
#> 17 0.1.0 more cpu 50454 my_worker 0 16.061 100.0 10.00 479.78906
#> 18 0.1.0 more cpu 50454 my_worker 0 17.066 99.6 9.96 340.88550
#> 19 0.1.0 more cpu 50454 my_worker 0 18.071 100.0 10.00 120.29133
#> 20 0.1.0 more cpu 50454 my_worker 0 19.077 99.7 9.97 124.50202
#> 21 0.1.0 more cpu 50454 my_worker 0 20.082 98.2 9.82 125.58336
#> 22 0.1.0 more cpu 50454 my_worker 0 21.087 99.7 9.97 125.38675
#> 23 0.1.0 third object 50454 my_worker 0 22.089 98.2 9.82 261.17734
#> 24 0.1.0 third object 50454 my_worker 0 23.092 99.5 9.95 564.98586
#> 25 0.1.0 third object 50454 my_worker 0 24.097 100.0 10.00 602.24307
#> virtual
#> 1 420736.6
#> 2 420736.6
#> 3 420745.0
#> 4 421545.0
#> 5 421545.0
#> 6 421553.4
#> 7 421561.8
#> 8 421561.8
#> 9 421561.8
#> 10 421561.8
#> 11 421561.8
#> 12 421561.8
#> 13 422361.8
#> 14 422361.8
#> 15 422361.8
#> 16 422361.8
#> 17 422361.8
#> 18 422361.8
#> 19 422361.8
#> 20 422361.8
#> 21 422361.8
#> 22 422361.8
#> 23 423161.8
#> 24 423161.8
#> 25 423161.8
autometric
also supports simple visualizations plot
performance metrics over time. To avoid depending on many other R
packages, autometric
only uses base plotting functionality.
Feel free to create fancier visualizations directly with ggplot2
.
log_plot(log_data, metric = "resident")
log_plot(log_data, phase = "more cpu", metric = "cpu")
autometric
heavily leverages fantastic work on the ps
R package by Jay Loden,
Dave Daeschler, Giampaolo Rodola, Gábor Csárdi, and Posit Software, PBC.
The source code of ps
was especially helpful for identifying appropriate system calls to
retrieve resource usage statistics. Attribution is given in the
Authors@R
field of the DESCRIPTION
file, the
LICENSE.note
file at the top level of the package, and in
the comments of the C files in src/
. Please visit https://github.com/r-lib/ps/blob/main/LICENSE.md to view
the license of ps
. ps
in turn is based on psutil
,
whose license is available at https://github.com/giampaolo/psutil/blob/master/LICENSE.
Please note that the autometric
project is released with
a Contributor Code of Conduct:
https://contributor-covenant.org/version/2/1/CODE_OF_CONDUCT.html
.
By contributing to this project, you agree to abide by its terms.
Logging to standard output is useful on clusters like SLURM where workers already redirect standard output to log files, or on the cloud where a service like Amazon CloudWatch captures messages instead of directing them to a physical file.↩︎
See also log_phase_get()
and log_phase_reset()
↩︎