From d1c2bf5e7c739bc5a7eeac602b477edb9f6630c2 Mon Sep 17 00:00:00 2001
From: Rodolfo Alonso Hernandez <ralonsoh@redhat.com>
Date: Wed, 2 Nov 2022 16:43:41 +0100
Subject: [PATCH] Add new service "file_tracker"

This new service periodically tracks the file open in the system.

Closes-Bug: #1995502
Change-Id: I02e097fef07655ff571af9f35bf258b2ed975098
---
 .zuul.yaml               |  4 ++++
 doc/source/debugging.rst |  6 +++++
 lib/dstat                |  6 +++++
 tools/file_tracker.sh    | 47 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 63 insertions(+)
 create mode 100755 tools/file_tracker.sh

diff --git a/.zuul.yaml b/.zuul.yaml
index 6dbb5bacbe..ce38760203 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -469,6 +469,7 @@
         dstat: false
         etcd3: true
         memory_tracker: true
+        file_tracker: true
         mysql: true
         rabbit: true
     group-vars:
@@ -477,6 +478,7 @@
           # Shared services
           dstat: false
           memory_tracker: true
+          file_tracker: true
         devstack_localrc:
           # Multinode specific settings
           HOST_IP: "{{ hostvars[inventory_hostname]['nodepool']['private_ipv4'] }}"
@@ -544,6 +546,7 @@
         dstat: false
         etcd3: true
         memory_tracker: true
+        file_tracker: true
         mysql: true
         rabbit: true
         tls-proxy: true
@@ -593,6 +596,7 @@
           # Shared services
           dstat: false
           memory_tracker: true
+          file_tracker: true
           tls-proxy: true
           # Nova services
           n-cpu: true
diff --git a/doc/source/debugging.rst b/doc/source/debugging.rst
index fd0d9cdf74..3ca0ad94b4 100644
--- a/doc/source/debugging.rst
+++ b/doc/source/debugging.rst
@@ -20,6 +20,12 @@ provides consumption output when available memory is seen to be
 falling (i.e. processes are consuming memory).  It also provides
 output showing locked (unswappable) memory.
 
+file_tracker
+------------
+
+The ``file_tracker`` service periodically monitors the number of
+open files in the system.
+
 tcpdump
 -------
 
diff --git a/lib/dstat b/lib/dstat
index eb03ae0fb2..870c901d2a 100644
--- a/lib/dstat
+++ b/lib/dstat
@@ -40,12 +40,18 @@ function start_dstat {
     if is_service_enabled peakmem_tracker; then
         die $LINENO "The peakmem_tracker service has been removed, use memory_tracker instead"
     fi
+
+    # To enable file_tracker add:
+    #    enable_service file_tracker
+    # to your localrc
+    run_process file_tracker "$TOP_DIR/tools/file_tracker.sh"
 }
 
 # stop_dstat() stop dstat process
 function stop_dstat {
     stop_process dstat
     stop_process memory_tracker
+    stop_process file_tracker
 }
 
 # Restore xtrace
diff --git a/tools/file_tracker.sh b/tools/file_tracker.sh
new file mode 100755
index 0000000000..9c31b30a56
--- /dev/null
+++ b/tools/file_tracker.sh
@@ -0,0 +1,47 @@
+#!/bin/bash
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+set -o errexit
+
+# time to sleep between checks
+SLEEP_TIME=20
+
+function tracker {
+    echo "Number of open files | Number of open files not in use | Maximum number of files allowed to be opened"
+    while true; do
+        cat /proc/sys/fs/file-nr
+        sleep $SLEEP_TIME
+    done
+}
+
+function usage {
+    echo "Usage: $0 [-x] [-s N]" 1>&2
+    exit 1
+}
+
+while getopts ":s:x" opt; do
+    case $opt in
+        s)
+            SLEEP_TIME=$OPTARG
+            ;;
+        x)
+            set -o xtrace
+            ;;
+        *)
+            usage
+            ;;
+    esac
+done
+
+tracker