From 31e29ddc904e94a42410f6c6f807b167607736de Mon Sep 17 00:00:00 2001
From: Krzysztof Ksiazek <krzysztof@ksiazek.info>
Date: Thu, 31 Aug 2017 10:47:52 +0200
Subject: [PATCH] Further improvements to reduce config reloading

---
 tools/proxysql_galera_checker.sh | 32 ++++++++++++++++++++++++--------
 1 file changed, 24 insertions(+), 8 deletions(-)

diff --git a/tools/proxysql_galera_checker.sh b/tools/proxysql_galera_checker.sh
index 86fba0b25..198277ad8 100755
--- a/tools/proxysql_galera_checker.sh
+++ b/tools/proxysql_galera_checker.sh
@@ -273,11 +273,19 @@ if [ ${NUMBER_WRITERS_ONLINE} -eq 0 ]; then
       do
         WSREP_STATUS=$($MYSQL_CMDLINE -h $server -P $port -e "SHOW STATUS LIKE 'wsrep_local_state'" 2>>${ERR_FILE} | tail -1 2>>${ERR_FILE})
         echo "`date` Check server $hostgroup:$server:$port for only available node in DONOR state, status $stat , wsrep_local_state $WSREP_STATUS" >> ${ERR_FILE}
-        if [ "${WSREP_STATUS}" = "2" -a "$stat" != "ONLINE" ]
+        if [ "${WSREP_STATUS}" = "2" -a "$stat" != "ONLINE" ] # if we are on Donor/Desync an not online in mysql_servers -> proceed
         then
-          change_server_status $HOSTGROUP_WRITER_ID "$server" $port "ONLINE" "WSREP status is DESYNC/DONOR, as this is the only node we will put this one online"
-          echo "1" > ${RELOAD_CHECK_FILE}
-          cnt=$(( $cnt + 1 ))
+          PROXY_RUNTIME_STATUS=$($PROXYSQL_CMDLINE "SELECT status FROM runtime_mysql_servers WHERE hostname='${server}' AND port='${port}' AND hostgroup_id='${hostgroup}'")
+          if [ "${PROXY_RUNTIME_STATUS}" != "ONLINE" ] # if we are not online in runtime_mysql_servers, proceed to change the server status and reload mysql_servers
+          then
+            change_server_status $HOSTGROUP_WRITER_ID "$server" $port "ONLINE" "WSREP status is DESYNC/DONOR, as this is the only node we will put this one online"
+            echo "1" > ${RELOAD_CHECK_FILE}
+            cnt=$(( $cnt + 1 ))
+          else # otherwise (we are already ONLINE in runtime_mysql_servers) no need to reload so let's just remove RELOAD_CHECK_FILE and update it to ONLINE in mysql_servers (in case something would reload it)
+            rm ${RELOAD_CHECK_FILE}
+            cnt=$(( $cnt + 1 ))
+            change_server_status $HOSTGROUP_WRITER_ID "$server" $port "ONLINE" "WSREP status is DESYNC/DONOR, as this is the only node we will put this one online"
+          fi
         fi
         safety_cnt=$(( $safety_cnt + 1 ))
     done
@@ -297,11 +305,19 @@ if [  ${HOSTGROUP_READER_ID} -ne -1 -a ${NUMBER_READERS_ONLINE} -eq 0 ]; then
       do
         WSREP_STATUS=$($MYSQL_CMDLINE -h $server -P $port -e "SHOW STATUS LIKE 'wsrep_local_state'" 2>>${ERR_FILE} | tail -1 2>>${ERR_FILE})
         echo "`date` Check server $hostgroup:$server:$port for only available node in DONOR state, status $stat , wsrep_local_state $WSREP_STATUS" >> ${ERR_FILE}
-        if [ "${WSREP_STATUS}" = "2" -a "$stat" != "ONLINE" ]
+        if [ "${WSREP_STATUS}" = "2" -a "$stat" != "ONLINE" ] # if we are on Donor/Desync an not online in mysql_servers -> proceed
         then
-          change_server_status $HOSTGROUP_READER_ID "$server" $port "ONLINE" "WSREP status is DESYNC/DONOR, as this is the only node we will put this one online"
-          echo "1" > ${RELOAD_CHECK_FILE}
-          cnt=$(( $cnt + 1 ))
+          PROXY_RUNTIME_STATUS=$($PROXYSQL_CMDLINE "SELECT status FROM runtime_mysql_servers WHERE hostname='${server}' AND port='${port}' AND hostgroup_id='${hostgroup}'")
+          if [ "${PROXY_RUNTIME_STATUS}" != "ONLINE" ] # if we are not online in runtime_mysql_servers, proceed to change the server status and reload mysql_servers
+          then
+            change_server_status $HOSTGROUP_READER_ID "$server" $port "ONLINE" "WSREP status is DESYNC/DONOR, as this is the only node we will put this one online"
+            echo "1" > ${RELOAD_CHECK_FILE}
+            cnt=$(( $cnt + 1 ))
+          else # otherwise (we are already ONLINE in runtime_mysql_servers) no need to reload so let's just remove RELOAD_CHECK_FILE and update it to ONLINE in mysql_servers (in case something would reload it)
+            rm ${RELOAD_CHECK_FILE}
+            cnt=$(( $cnt + 1 ))
+            change_server_status $HOSTGROUP_READER_ID "$server" $port "ONLINE" "WSREP status is DESYNC/DONOR, as this is the only node we will put this one online"
+          fi
         fi
         safety_cnt=$(( $safety_cnt + 1 ))
     done