From b6c41ca5e2678af0a983b62da0a9b7da9c51654a Mon Sep 17 00:00:00 2001
From: Ben Peddell <klightspeed@killerwolves.net>
Date: Thu, 29 Sep 2016 22:54:00 +1000
Subject: [PATCH] Restart the server if it stops listening

---
 tools/arkmanager | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/tools/arkmanager b/tools/arkmanager
index 9a32289..f690b68 100755
--- a/tools/arkmanager
+++ b/tools/arkmanager
@@ -920,6 +920,8 @@ doRun() {
       restartserver=1
       touch "$arkserverroot/$arkautorestartfile"
     fi
+    # Retries for checking it the server comes back up after going down
+    serverdowntries=0
 
     sleep 5
 
@@ -927,6 +929,7 @@ doRun() {
       # Grab the current server PID
       local pid="`getServerPID`"
       if [ "$pid" == "$serverpid" ]; then
+        serverdowntries=0
         if [ "$restartserver" -eq 0 ]; then
           # Check if the server has fully started
           if ! isTheServerUp; then
@@ -935,6 +938,28 @@ doRun() {
             touch "$arkserverroot/$arkautorestartfile"
             restartserver=1
           fi
+        elif isTheServerUp; then
+          (( serverdowntries++ ))
+
+          if (( serverdowntries > 12 )); then
+            # Server has not been listening for 60 seconds, so restart it.
+            echo "`timestamp`: The server has stopped listening"
+            echo "`timestamp`: Restarting server"
+            for (( i = 0; i < 5; i++ )); do
+              if ! kill -0 "$serverpid"; then
+                break
+              fi
+              kill -INT "$serverpid"
+              sleep 5
+            done
+            if kill -0 "$serverpid"; then
+              echo "`timestamp`: Graceful restart failed - killing server"
+              kill -KILL "$serverpid"
+            fi
+
+            # Exit the server check loop
+            break
+          fi
 	fi
       else
         echo "`timestamp`: Bad PID '$pid'; expected '$serverpid'"