extras: Script to collect system-stats

For debugging performance issues we found that this script is very
useful.  Script collects the stats of vmstat/iostat/top/sar to get
metrics about memory/disk/cpu/network respectively at the configured
interval. It is very important to collect all these metrics at the
same time so that they can be correlated easily, so made this into a
script

fixes bz#1633926
Change-Id: Iea52e55179b21c505953722c8898293fe92cb8de
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>

extras/collect-system-stats.sh

@@ -0,0 +1,52 @@
+#!/bin/bash
+################################################################################
+# Usage: collect-system-stats.sh <delay-in-seconds>
+# This script starts sar/top/iostat/vmstat processes which collect system stats
+# with the interval <delay-in-seconds> given as argument to the script. When
+# the script is stopped either by entering any input or Ctrl+C the list of
+# files where output is captured will be printed on the screen which can be
+# observed to find any problems/bottlenecks.
+###############################################################################
+
+function stop_processes {
+        echo "Stopping the monitoring processes"
+        echo "sar pid:$sar_pid", "top pid: $top_pid", "iostat pid: $iostat_pid", "vmstat pid: $vmstat_pid"
+        kill "$sar_pid" "$top_pid" "$iostat_pid" "$vmstat_pid"
+        echo "Files created: ${timestamp}-network.out, ${timestamp}-top.out, ${timestamp}-iostat.out, ${timestamp}-vmstat.out"
+}
+
+function check_dependent_commands_exist()
+{
+        declare -a arr=("sar" "top" "iostat" "vmstat")
+        for i in "${arr[@]}"
+        do
+                if ! command -v "$i" > /dev/null 2>&1
+                then
+                        echo "ERROR: '$i' command is not found"
+                        exit 1
+                fi
+        done
+
+}
+
+case "$1" in
+    ''|*[!0-9]*) echo "Usage: $0 <delay-between-successive-metrics-collection-in-seconds>"; exit 1 ;;
+    *) interval="$1" ;;
+esac
+
+timestamp=$(date +"%s")
+
+check_dependent_commands_exist
+sar -n DEV "$interval" > "${timestamp}"-network.out &
+sar_pid="$!"
+top -bHd "$interval" > "${timestamp}"-top.out &
+top_pid="$!"
+iostat -Ntkdx "$interval" > "${timestamp}"-iostat.out &
+iostat_pid="$!"
+vmstat -t "$interval" > "${timestamp}"-vmstat.out &
+vmstat_pid="$!"
+echo "Started sar, vmstat, iostat, top for collecting stats"
+
+
+trap stop_processes EXIT
+read -r -p "Press anything and ENTER to exit";