adding small key diff based on snapshots

.gitignore

@@ -1,4 +1,5 @@
 omc
 omc-v1.4.0_Linux_x86_64.tar.gz
 build.sh
-push.sh
+push.sh
+default.etcd

README.md

@@ -34,6 +34,14 @@ or
 > podman run --privileged --volume /$(pwd):/test quay.io/peterducai/openshift-etcd-suite:latest etcd /test/\<path-to-must-gather\>
 
 
+## snap_diff.sh script
+
+This can be used to debug why a database file is bigger compared to some snapshot before. It creates a diff between the keys to understand where such increase might come from.
+
+> ./snap_diff.sh first.snapshot second.snapshot diff.txt
+
+the qualified diff in keys can be found in a newly created file `diff.txt`.
+
 ## fio_suite
 
 fio_suite is benchmark tool which runs several fio tests to see how IOPS change under different load.

snap_diff.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+# dump_keys <snapshot file> <output file>
+function dump_keys() {
+   rm -rf default.etcd
+   etcdctl snapshot restore "$1"
+
+   etcd --enable-pprof &
+   etcdPid=$!
+
+   # wait for it to come up
+   etcdctl member list      
+   etcdctl get / --prefix --keys-only | awk NF | sort -n > "$2"
+
+   kill -9 $etcdPid
+}
+
+if [ "$#" -ne 3 ]; then
+    echo "./snap_diff.sh <snapshot file> <snapshot file> <output diff>"
+    exit 1
+fi
+
+first=$(mktemp)
+dump_keys $1 $first
+second=$(mktemp)
+dump_keys $2 $second
+
+diff $first $second > $3
+echo "diff $first $second -> $3"