Enable CSV logging output for DStat.
Future work toward visualization of DevStack and devstack-gate performance
would benefit greatly from the availability of machine-parsable DStat output.
This patch outputs an additional logfile to $LOGDIR, `dstat-csv.log`, using
DStat's built-in CSV logging functionality.
An additional instance of DStat is started during start_dstat that outputs
to CSV-formatted text without `--top-cpu-adv` and `-top-io-adv` enabled, as
these plugins are currently incompatible with CSV output. To facilitate this,
a new `dstat.sh` script is added to $TOP_DIR/tools/ to act as a daemon to
manage the two processes.
Change-Id: I826c94c35b6a109308b4f132c181ff7a1f63bc7b
Depends-On: I534fb1f9356a7948d2fec0aecc7f275e47362a11
diff --git a/tools/dstat.sh b/tools/dstat.sh
new file mode 100755
index 0000000..6ba4515
--- /dev/null
+++ b/tools/dstat.sh
@@ -0,0 +1,32 @@
+#!/bin/bash
+
+# **tools/dstat.sh** - Execute instances of DStat to log system load info
+#
+# Multiple instances of DStat are executed in order to take advantage of
+# incompatible features, particularly CSV output and the "top-cpu-adv" and
+# "top-io-adv" flags.
+#
+# Assumes:
+# - dstat command is installed
+
+# Retreive log directory as argument from calling script.
+LOGDIR=$1
+
+# Command line arguments for primary DStat process.
+DSTAT_OPTS="-tcmndrylpg --top-cpu-adv --top-io-adv"
+
+# Command-line arguments for secondary background DStat process.
+DSTAT_CSV_OPTS="-tcmndrylpg --output $LOGDIR/dstat-csv.log"
+
+# Execute and background the secondary dstat process and discard its output.
+dstat $DSTAT_CSV_OPTS >& /dev/null &
+
+# Execute and background the primary dstat process, but keep its output in this
+# TTY.
+dstat $DSTAT_OPTS &
+
+# Catch any exit signals, making sure to also terminate any child processes.
+trap "kill -- -$$" EXIT
+
+# Keep this script running as long as child dstat processes are alive.
+wait