Replace deprecated translog flush setting in ES

Author: antkaynak

share/github-backup-utils/ghe-backup-es-rsync

@@ -39,6 +39,12 @@ if [ -d "$GHE_DATA_DIR/current/elasticsearch" ]; then
   link_dest="--link-dest=../../current/elasticsearch"
 fi
 
+# Store the existing flush_threshold_size setting if it exists and if does not set it to ES default
+current_threshold=$(ghe-ssh "$host" -- curl -s "localhost:9200/_settings" | jq -r '.[].settings.index.translog.flush_threshold_size')
+if [ -z "$current_threshold" ]; then
+  current_threshold="512MB"
+fi
+
 # Transfer ES indices from a GitHub instance to the current snapshot
 # directory, using a previous snapshot to avoid transferring files that have
 # already been transferred.
@@ -54,15 +60,15 @@ log_rsync "END elasticsearch rsync" 1>&3
 # Set up a trap to re-enable flushing on exit and remove temp file
 cleanup () {
   ghe_verbose "* Enabling ES index flushing ..."
-  echo '{"index":{"translog.disable_flush":false}}' |
+  echo "{\"index\":{\"index.translog.flush_threshold_size\":\"$current_threshold\"}}" |
   ghe-ssh "$host" -- curl -s -XPUT "localhost:9200/_settings" -d @- >/dev/null
 }
 trap 'cleanup' EXIT
 trap 'exit $?' INT # ^C always terminate
 
 # Disable ES flushing and force a flush right now
 ghe_verbose "* Disabling ES index flushing ..."
-echo '{"index":{"translog.disable_flush":true}}' |
+echo '{"index":{"index.translog.flush_threshold_size":"1PB"}}' |
 ghe-ssh "$host" -- curl -s -XPUT  "localhost:9200/_settings" -d @- >/dev/null
 ghe-ssh "$host" -- curl -s -XPOST "localhost:9200/_flush" >/dev/null