From be576c81de3457675893c3e76f65f529c7e9c1e5 Mon Sep 17 00:00:00 2001
From: Francisco Miguel Biete <fmbiete@gmail.com>
Date: Mon, 22 Aug 2016 14:48:00 +0100
Subject: [PATCH 1/3] Add writer, reader hostgroup functionality to
 proxysql_galera_checker.sh

---
 tools/proxysql_galera_checker.sh | 94 ++++++++++++++++++++++++++------
 1 file changed, 76 insertions(+), 18 deletions(-)

diff --git a/tools/proxysql_galera_checker.sh b/tools/proxysql_galera_checker.sh
index 8f5828414..863807528 100755
--- a/tools/proxysql_galera_checker.sh
+++ b/tools/proxysql_galera_checker.sh
@@ -1,24 +1,46 @@
 #!/bin/bash
-
 ## inspired by Percona clustercheck.sh
-if [ "$1" = '-h' -o "$1" = '--help'  -o -z "$1" ]; then
-  echo "Usage: $0 <hostname> <port> <hostgroup_id> <log_file>" && exit 0
+
+# CHANGE THOSE
+PROXYSQL_USERNAME="admin"
+PROXYSQL_PASSWORD="admin"
+PROXYSQL_HOSTNAME="localhost"
+PROXYSQL_PORT="6032"
+#
+
+if [ "$1" = '-h' -o "$1" = '--help'  -o -z "$1" ]
+then
+  usage
 fi
-if [ $# -lt 3 ]; then
+
+if [ $# -lt 1 ]
+then
   echo "Invalid number of arguments"
-  echo "Usage: $0 <hostname> <port> <hostgroup_id> <log_file>" && exit 1
+  usage
 fi
 
-PROXYSQL_USERNAME="admin"
-PROXYSQL_PASSWORD="admin"
-PROXYSQL_HOSTNAME="${1}"
-PROXYSQL_PORT="${2}"
-HOSTGROUP_ID="${3}"
-ERR_FILE="${4:-/dev/null}"
+function usage()
+{
+  echo "Usage: $0 <hostgroup_id write> [hostgroup_id read] [number writers] [writers are readers 0|1} [log_file]"
+  exit 0
+}
+
+HOSTGROUP_WRITER_ID="${1}"
+HOSTGROUP_READER_ID="${2:--1}"
+NUMBER_WRITERS="${3:-0}"
+WRITER_IS_READER="${4:-1}"
+ERR_FILE="${5:-/dev/null}"
+
+#echo "Hostgroup writers $HOSTGROUP_WRITER_ID"
+#echo "Hostgroup readers $HOSTGROUP_READER_ID"
+#echo "Number of writers $NUMBER_WRITERS"
+#echo "Writers are readers $WRITER_IS_READER"
+#echo "log file $ERR_FILE"
+
 #Timeout exists for instances where mysqld may be hung
 TIMEOUT=10
 
-PROXYSQL_CMDLINE="mysql -u$PROXYSQL_USERNAME -p$PROXYSQL_PASSWORD -h $PROXYSQL_HOSTNAME -P $PROXYSQL_PORT -Ne"
+PROXYSQL_CMDLINE="mysql -u$PROXYSQL_USERNAME -p$PROXYSQL_PASSWORD -h $PROXYSQL_HOSTNAME -P $PROXYSQL_PORT --protocol=tcp -Nse"
 MYSQL_CREDENTIALS=$($PROXYSQL_CMDLINE "SELECT variable_value FROM global_variables WHERE variable_name IN ('mysql-monitor_username','mysql-monitor_password') ORDER BY variable_name DESC")
 MYSQL_USERNAME=$(echo $MYSQL_CREDENTIALS | awk '{print $1}')
 MYSQL_PASSWORD=$(echo $MYSQL_CREDENTIALS | awk '{print $2}')
@@ -26,16 +48,52 @@ MYSQL_PASSWORD=$(echo $MYSQL_CREDENTIALS | awk '{print $2}')
 #echo $MYSQL_USERNAME $MYSQL_PASSWORD
 MYSQL_CMDLINE="timeout $TIMEOUT mysql -nNE -u$MYSQL_USERNAME -p$MYSQL_PASSWORD "
 
-$PROXYSQL_CMDLINE "SELECT hostname,port,status FROM mysql_servers WHERE hostgroup_id='$HOSTGROUP_ID' AND status<>'OFFLINE_HARD'" | while read server port stat
+$PROXYSQL_CMDLINE "SELECT hostgroup_id, hostname, port, status FROM mysql_servers WHERE hostgroup_id IN ($HOSTGROUP_WRITER_ID, $HOSTGROUP_READER_ID) AND status <> 'OFFLINE_HARD'" | while read hostgroup server port stat
 do
   WSREP_STATUS=$($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 $server:$port , status $stat , wsrep_local_state $WSREP_STATUS >> ${ERR_FILE}
+  echo "`date` Check server $hostgroup:$server:$port , status $stat , wsrep_local_state $WSREP_STATUS" >> ${ERR_FILE}
   if [ "${WSREP_STATUS}" = "4" -a "$stat" != "ONLINE" ] ; then
-    echo `date` Changing server $server:$port to status ONLINE >> ${ERR_FILE}
-    $PROXYSQL_CMDLINE "UPDATE mysql_servers SET status='ONLINE' WHERE hostgroup_id=$HOSTGROUP_ID AND hostname='$server' AND port='$port'; LOAD MYSQL SERVERS TO RUNTIME;" 2>> ${ERR_FILE}
+    echo "`date` Changing server $hostgroup:$server:$port to status ONLINE" >> ${ERR_FILE}
+    $PROXYSQL_CMDLINE "UPDATE mysql_servers SET status='ONLINE' WHERE hostgroup_id=$hostgroup AND hostname='$server' AND port='$port';" 2>> ${ERR_FILE}
   elif [ "${WSREP_STATUS}" != "4" -a "$stat" = "ONLINE" ] ; then
-    echo `date` Changing server $server:$port to status OFFLINE_SOFT >> ${ERR_FILE}
-    $PROXYSQL_CMDLINE "UPDATE mysql_servers SET status='OFFLINE_SOFT' WHERE hostgroup_id=$HOSTGROUP_ID AND hostname='$server' AND port='$port'; LOAD MYSQL SERVERS TO RUNTIME;" 2>> ${ERR_FILE}
+    echo "`date` Changing server $hostgroup:$server:$port to status OFFLINE_SOFT" >> ${ERR_FILE}
+    $PROXYSQL_CMDLINE "UPDATE mysql_servers SET status='OFFLINE_SOFT' WHERE hostgroup_id=$hostgroup AND hostname='$server' AND port='$port';" 2>> ${ERR_FILE}
   fi
 done
+
+if [ $NUMBER_WRITERS -gt 0 ]
+then
+  CONT=0
+  # Only check online servers
+  $PROXYSQL_CMDLINE "SELECT hostname, port FROM mysql_servers WHERE hostgroup_id = $HOSTGROUP_WRITER_ID AND status = 'ONLINE' order by hostname, port" | while read server port
+  do
+    if [ $CONT -ge $NUMBER_WRITERS ]
+    then
+      # Number of writers reached, disabling extra servers
+      echo "`date` Number of writers reached, disabling extra write server $HOSTGROUP_WRITER_ID:$server:$port to status OFFLINE_SOFT" >> ${ERR_FILE}
+      $PROXYSQL_CMDLINE "UPDATE mysql_servers set status = 'OFFLINE_SOFT' WHERE hostgroup_id = $HOSTGROUP_WRITER_ID AND hostname = '$server' AND port = $port;" 2>> ${ERR_FILE}
+    fi
+    CONT=$(( $CONT + 1 ))
+  done
+fi
+
+if [ $WRITER_IS_READER -eq 0 ]
+then
+  # Writer is not a read node, but only if we have another read node online
+  READER_NON_WRITER=$($PROXYSQL_CMDLINE "SELECT count(*) FROM mysql_servers ms1 LEFT JOIN mysql_servers ms2 ON ms1.hostname = ms2.hostname AND ms1.port = ms2.port AND ms1.hostgroup_id <> ms2.hostgroup_id WHERE ms1.hostgroup_id = $HOSTGROUP_READER_ID AND (ms2.hostgroup_id = $HOSTGROUP_WRITER_ID OR ms2.hostgroup_id IS NULL) AND (ms2.status = 'OFFLINE_SOFT' OR ms2.hostgroup_id IS NULL);" 2>>${ERR_FILE})
+  if [ $READER_NON_WRITER -gt 0 ]
+  then
+    $PROXYSQL_CMDLINE "SELECT hostname, port FROM mysql_servers WHERE hostgroup_id = $HOSTGROUP_WRITER_ID AND status = 'ONLINE' order by hostname, port" | while read server port
+    do
+      echo "`date` Disabling read for write server $HOSTGROUP_READER_ID:$server:$port to status OFFLINE_SOFT" >> ${ERR_FILE}
+      $PROXYSQL_CMDLINE "UPDATE mysql_servers set status = 'OFFLINE_SOFT' WHERE hostgroup_id = $HOSTGROUP_READER_ID AND hostname = '$server' AND port = $port;" 2>> ${ERR_FILE}
+    done
+  else
+    echo "`date` Not enough read servers, we won't disable read in write servers" >> ${ERR_FILE}
+  fi
+fi
+
+echo "`date` Enabling config" >> ${ERR_FILE}
+$PROXYSQL_CMDLINE "LOAD MYSQL SERVERS TO RUNTIME;" 2>> ${ERR_FILE}
+
 exit 0

From d0e9489a101c70a5f84dc2d0d5951b57c1cfb60a Mon Sep 17 00:00:00 2001
From: Francisco Miguel Biete <fmbiete@gmail.com>
Date: Mon, 22 Aug 2016 15:15:54 +0100
Subject: [PATCH 2/3] Special situation: don't disable read in writers when
 there are not readers online

---
 tools/proxysql_galera_checker.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/proxysql_galera_checker.sh b/tools/proxysql_galera_checker.sh
index 863807528..f718b4aff 100755
--- a/tools/proxysql_galera_checker.sh
+++ b/tools/proxysql_galera_checker.sh
@@ -80,7 +80,7 @@ fi
 if [ $WRITER_IS_READER -eq 0 ]
 then
   # Writer is not a read node, but only if we have another read node online
-  READER_NON_WRITER=$($PROXYSQL_CMDLINE "SELECT count(*) FROM mysql_servers ms1 LEFT JOIN mysql_servers ms2 ON ms1.hostname = ms2.hostname AND ms1.port = ms2.port AND ms1.hostgroup_id <> ms2.hostgroup_id WHERE ms1.hostgroup_id = $HOSTGROUP_READER_ID AND (ms2.hostgroup_id = $HOSTGROUP_WRITER_ID OR ms2.hostgroup_id IS NULL) AND (ms2.status = 'OFFLINE_SOFT' OR ms2.hostgroup_id IS NULL);" 2>>${ERR_FILE})
+  READER_NON_WRITER=$($PROXYSQL_CMDLINE "SELECT count(*) FROM mysql_servers ms1 LEFT JOIN mysql_servers ms2 ON ms1.hostname = ms2.hostname AND ms1.port = ms2.port AND ms1.hostgroup_id <> ms2.hostgroup_id WHERE ms1.hostgroup_id = $HOSTGROUP_READER_ID AND ms1.status = 'ONLINE' AND (ms2.hostgroup_id = $HOSTGROUP_WRITER_ID OR ms2.hostgroup_id IS NULL) AND (ms2.status = 'OFFLINE_SOFT' OR ms2.hostgroup_id IS NULL);" 2>>${ERR_FILE})
   if [ $READER_NON_WRITER -gt 0 ]
   then
     $PROXYSQL_CMDLINE "SELECT hostname, port FROM mysql_servers WHERE hostgroup_id = $HOSTGROUP_WRITER_ID AND status = 'ONLINE' order by hostname, port" | while read server port

From 226bfa24d665e5d2edd71ef85231a33cdf0ab520 Mon Sep 17 00:00:00 2001
From: Francisco Miguel Biete <fmbiete@gmail.com>
Date: Tue, 23 Aug 2016 08:43:53 +0100
Subject: [PATCH 3/3] Fix: usage function must be defined before actual use

---
 tools/proxysql_galera_checker.sh | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/tools/proxysql_galera_checker.sh b/tools/proxysql_galera_checker.sh
index f718b4aff..a119396ee 100755
--- a/tools/proxysql_galera_checker.sh
+++ b/tools/proxysql_galera_checker.sh
@@ -8,6 +8,12 @@ PROXYSQL_HOSTNAME="localhost"
 PROXYSQL_PORT="6032"
 #
 
+function usage()
+{
+  echo "Usage: $0 <hostgroup_id write> [hostgroup_id read] [number writers] [writers are readers 0|1} [log_file]"
+  exit 0
+}
+
 if [ "$1" = '-h' -o "$1" = '--help'  -o -z "$1" ]
 then
   usage
@@ -19,12 +25,6 @@ then
   usage
 fi
 
-function usage()
-{
-  echo "Usage: $0 <hostgroup_id write> [hostgroup_id read] [number writers] [writers are readers 0|1} [log_file]"
-  exit 0
-}
-
 HOSTGROUP_WRITER_ID="${1}"
 HOSTGROUP_READER_ID="${2:--1}"
 NUMBER_WRITERS="${3:-0}"