Consul Asynchronous Slave Check

check_async_mysql.sh

# script used in consul to check if mysql is primary master and asynchronous slave
# v.0.1 - lefred 2018-02-16

SLAVEOFDC="dc2"
SLAVEUSER="async_repl"
SLAVEPWD="asyncpwd"

# check if we are the primary one
ROLE=$(mysql -h 127.0.0.1 -BNe "select MEMBER_ROLE from performance_schema.replication_group_members where MEMBER_HOST=@@hostname")

if [[ "${ROLE}" == "PRIMARY" ]]
then
 # let's set the kv of the primary
 curl -s --request PUT --data "$(hostname)"  http://localhost:8500/v1/kv/primary
 # check if replication is setup and running
 read -r current_master io_running sql_running <<<$(mysql -h 127.0.0.1 -P 3306 -Be 'show slave status\G' | grep '_Running:\|_Host:' | cut -d':' -f2)
 otherdcmaster=$(curl -s "http://localhost:8500/v1/kv/primary?raw&dc=${SLAVEOFDC}")
 echo "Current master: ${current_master}  ${SLAVEOFDC} Primary: ${otherdcmaster}"
 echo "IO: ${io_running}  SQL: ${sql_running}"
 if [[ "${current_master}" != "${otherdcmaster}" ]]
 then
   mysql -h 127.0.0.1 -P 3306 -e "STOP SLAVE; CHANGE MASTER TO MASTER_HOST='${otherdcmaster}'; START SLAVE"
   sleep 5
 fi

 if [[ "${io_running}" == "Yes" ]] && [[ "${sql_running}" == "Yes" ]]
 then
   echo "This is the Primary Master and Async replication is running"
   exit 0
 elif [[ "${io_running}" == "Yes" ]] && [[ "${sql_running}" == "No" ]]
 then
   echo "This is the Primary Master but Async replication SQL thread not running... starting it"
   mysql -h 127.0.0.1 -P 3306 -e "START SLAVE SQL_THREAD"
 elif [[ "${io_running}" == "No" ]] && [[ "${sql_running}" == "Yes" ]]
 then 
   echo "This is the Primary Master but Async replication IO thread not running... starting it"
   mysql -h 127.0.0.1 -P 3306 -e "START SLAVE IO_THREAD"
 elif [[ "${io_running}" == "No" ]] && [[ "${sql_running}" == "No" ]]
 then
   echo "This is the Primary Master but Async replication is not running... starting it"
   mysql -h 127.0.0.1 -P 3306 -e "START SLAVE"
 else
   echo "This was not yet an async slave, setting it up"
   mysql -h 127.0.0.1 -P 3306 -e "STOP SLAVE;CHANGE MASTER TO MASTER_HOST='${otherdcmaster}',
MASTER_PORT=3306, MASTER_USER='$SLAVEUSER', MASTER_PASSWORD='$SLAVEPWD',
MASTER_AUTO_POSITION=1; START SLAVE"
   exit 2
 fi
 exit 1
else
 # check if replication is running
 read -r io_running sql_running <<<$(mysql -h 127.0.0.1 -P 3306 -Be 'show slave status\G' | grep '_Running:' | cut -d':' -f2)
 if [[ "${io_running}" == "Yes" ]] || [[ "${sql_running}" == "Yes" ]]
 then 
    echo "Replication should not be working, let's stop it"
    mysql -h 127.0.0.1 -P 3306 -e "STOP SLAVE"
 fi
fi
echo "Not Primary and not Async Slave"
exit 0# v.0.1 - lefred 2018-02-16

SLAVEOFDC="dc2"
SLAVEUSER="async_repl"
SLAVEPWD="asyncpwd"

# check if we are the primary one
ROLE=$(mysql -h 127.0.0.1 -BNe "select MEMBER_ROLE from performance_schema.replication_group_members where MEMBER_HOST=@@hostname")

if [[ "${ROLE}" == "PRIMARY" ]]
then
 # let's set the kv of the primary
 curl -s --request PUT --data "$(hostname)"  http://localhost:8500/v1/kv/primary

 # check if replication is setup and running
 read -r current_master io_running sql_running <<<$(mysql -h 127.0.0.1 -P 3306 -Be 'show slave status\G' | grep '_Running:\|_Host:' | cut -d':' -f2)
 otherdcmaster=$(curl -s "http://localhost:8500/v1/kv/primary?raw&dc=${SLAVEOFDC}")
 echo "Current master: ${current_master}  ${SLAVEOFDC} Primary: ${otherdcmaster}"
 echo "IO: ${io_running}  SQL: ${sql_running}"
 if [[ "${current_master}" != "${otherdcmaster}" ]]
 then
   mysql -h 127.0.0.1 -P 3306 -e "STOP SLAVE; CHANGE MASTER TO MASTER_HOST='${otherdcmaster}'; START SLAVE"
   sleep 5
 fi

 if [[ "${io_running}" == "Yes" ]] && [[ "${sql_running}" == "Yes" ]]
 then
   echo "This is the Primary Master and Async replication is running"
   exit 0
 elif [[ "${io_running}" == "Yes" ]] && [[ "${sql_running}" == "No" ]]
 then
   echo "This is the Primary Master but Async replication SQL thread not running... starting it"
   mysql -h 127.0.0.1 -P 3306 -e "START SLAVE SQL_THREAD"
 elif [[ "${io_running}" == "No" ]] && [[ "${sql_running}" == "Yes" ]]
 then 
   echo "This is the Primary Master but Async replication IO thread not running... starting it"
   mysql -h 127.0.0.1 -P 3306 -e "START SLAVE IO_THREAD"
 elif [[ "${io_running}" == "No" ]] && [[ "${sql_running}" == "No" ]]
 then
   echo "This is the Primary Master but Async replication is not running... starting it"
   mysql -h 127.0.0.1 -P 3306 -e "START SLAVE"
 else
   echo "This was not yet an async slave, settting it up"
   mysql -h 127.0.0.1 -P 3306 -e "CHANGE MASTER TO MASTER_HOST='${otherdcmaster}',
MASTER_PORT=3306, MASTER_USER='$SLAVEUSER', MASTER_PASSWORD='$SLAVEPWD',
MASTER_AUTO_POSITION=1; START SLAVE"
   exit 2
 fi
 exit 1
else
 # check if replication is running
 read -r io_running sql_running <<<$(mysql -h 127.0.0.1 -P 3306 -Be 'show slave status\G' | grep '_Running:' | cut -d':' -f2)
 if [[ "${io_running}" == "Yes" ]] || [[ "${sql_running}" == "Yes" ]]
 then 
    echo "Replication should not be working, let's stop it"
    mysql -h 127.0.0.1 -P 3306 -e "STOP SLAVE"
 fi
fi
echo "Not Primary and not Async Slave"
exit 0