Ensuring transparent high availability and scalability for your application.

1. © 2019 Percona1
Vinicius M. Grippa
Brothers in Arms: Using ProxySQL + PXC
Ensuring transparent high availability and scalability for your application
Support Engineer for MySQL / MongoDB

2. © 2019 Percona2
About Percona
▪ Solutions for your success with MySQL, MongoDB, and PostgreSQL
▪ Support, Consulting, Managed Services, and Software
▪ Our Software is 100% Open Source and Free
▪ Support Broad Ecosystem
▪ MySQL, MariaDB, Amazon RDS, and others
▪ In Business for 12 years
▪ More than 3000 customers, including top Internet companies and
enterprises

3. © 2019 Percona3
About me
▪ Support Engineer at Percona since 2017
▪ Working with MySQL for over 6 years
▪ Working with Databases for over 9 years
▪ Speaker at Percona Live

4. © 2019 Percona4
Percona XtraDB Cluster

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Traditional MySQL replication
- Replication delay
- Switchover interval
- Single point of failure
- Data integrity problem

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PXC/Galera
- All nodes can act as a master
- Data integrity
- Synchronous replication
- Read scalability

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Automatic Node Provisioning
- Bootstrapping cluster
- SST (Snapshot State Transfer)
(rsync, xtrabackup, mysqldump)
- IST(incremental state transfer)
Auto-catchup cluster state

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Workload Conflict
- Brute force abort
- Forceful abort of conflicting
transaction
- Certification failure

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Flow Control
- Trx are queued. Queue full can cause
flow-control
- Dynamic Control of the workload

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Cluster-safe-mode
- Workload that is not safe to the
cluster
- Pxc_strict_mode
(Enforcing,
Master,
Permissive,
Disabled)

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Load Balancer
- PXC can operate with multiple load
balancers (HA Proxy, ProxySQL,
etc…)
- PXC suggests ProxySQL
- Integrated and close
development
- Feature rich load balancer

12. © 2019 Percona12
ProxySQL 2.0

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ProxySQL Features
•Query Caching
•Query Routing
•Firewall
•Advanced configuration with 0 downtime
•ProxySQL cluster
•Open source :)

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ProxySQL topology

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ProxySQL topology

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ProxySQL topology

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ProxySQL 2.0
•ProxySQL v2.0 has native support for Galera Clustering (In previous versions of
ProxySQL an external scheduler was required to track the status of Galera nodes)
•Introduces mysql_galera_hostgroups and
mysql_server_galera_log tables

18. © 2019 Percona18
ProxySQL Configuration

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ProxySQL Example
IPs
172.16.2.181 - node3
172.16.1.54 - node2
172.16.3.136 - node1
Hostgroups
Writer HG-> 100
Reader HG-> 101
BackupW HG-> 102
offHG HG-> 9101

20. © 2019 Percona20
ProxySQL Example
Servers first:
INSERT INTO mysql_servers (hostname,hostgroup_id,port,weight)
VALUES ('172.16.2.181',101,3306,1000);
INSERT INTO mysql_servers (hostname,hostgroup_id,port,weight)
VALUES ('172.16.1.54',101,3306,100);
INSERT INTO mysql_servers (hostname,hostgroup_id,port,weight)
VALUES ('172.16.3.136',101,3306,100);
save mysql servers to disk;
load mysql servers to runtime;

21. © 2019 Percona21
ProxySQL Example
Creating user (it is necessary to create the user on PXC as well):
insert into mysql_users (username,
password,default_hostgroup) values ('app_test','app_test',
100);
load mysql users to runtime;
save mysql users from runtime;
save mysql users to disk;

22. © 2019 Percona22
ProxySQL Example
Creating Rules:
insert into mysql_query_rules
(rule_id,proxy_port,schemaname,username,destination_hostgroup,active,
retries,match_digest,apply)
values(1040,6033,'*','app_test',100,1,3,'^SELECT.*FOR UPDATE',1);
insert into mysql_query_rules
(rule_id,proxy_port,schemaname,username,destination_hostgroup,active,
retries,match_digest,apply)
values(1041,6033,'*','app_test',101,1,3,'^SELECT.*@@',1);
save mysql query rules to disk;
load mysql query rules to run;

23. © 2019 Percona23
ProxySQL Example
Then the galera settings:
insert into mysql_galera_hostgroups
(writer_hostgroup,backup_writer_hostgroup,reader_hostgroup,
offline_hostgroup,active,max_writers,writer_is_also_reader,ma
x_transactions_behind) values (100,102,101,9101,0,1,1,16);
# max_transactions_behind - determines the maximum number of writesets
behind the cluster that ProxySQL should allow before shunning the node to
prevent stale reads (this is determined by querying the
wsrep_local_recv_queue Galera variable).

24. © 2019 Percona24
ProxySQL Example
Setting version:
update global_variables set variable_value='5.7.25' where
variable_name='mysql-server_version';
LOAD MYSQL VARIABLES TO RUNTIME;SAVE MYSQL VARIABLES TO DISK;

25. © 2019 Percona25
ProxySQL Example
Create monitor user on MySQL and adjust on ProxySQL:
UPDATE global_variables SET variable_value='admin'WHERE
variable_name='mysql-monitor_username';
UPDATE global_variables SET variable_value='admin'WHERE
variable_name='mysql-monitor_password';

26. © 2019 Percona26
ProxySQL Example
PXC: admin@127.0.0.1 ((none)) > select * from
runtime_mysql_galera_hostgroups G
*************************** 1. row ***************************
writer_hostgroup: 100
backup_writer_hostgroup: 102
reader_hostgroup: 101
offline_hostgroup: 9101
active: 0 ← https://github.com/sysown/proxysql/issues/1902
max_writers: 1
writer_is_also_reader: 1
max_transactions_behind: 16
comment: NULL
1 row in set (0.01 sec)

27. © 2019 Percona27
ProxySQL+PXC Features
PXC: root@localhost ((none)) > set global pxc_maint_mode = maintenance;
# Sends a shutdown signal
$ systemctl stop mysqld

28. © 2019 Percona28
ProxySQL Features
PXC: admin@127.0.0.1 ((none)) > select hostgroup_id,hostname,status from
runtime_mysql_servers;
+--------------+--------------+---------+
| hostgroup_id | hostname | status |
+--------------+--------------+---------+
| 101 | 172.16.2.181 | ONLINE |
| 9101 | 172.16.1.54 | SHUNNED |
| 9101 | 172.16.3.136 | SHUNNED |
| 100 | 172.16.2.181 | ONLINE |
+--------------+--------------+---------+
4 rows in set (0.00 sec)

29. © 2019 Percona29
ProxySQL Features

30. © 2019 Percona30
Compile
yum install make cmake gcc gcc-c++ epel-release
https://dev.mysql.com/get/mysql80-community-release-el7-2.noarch.rpm git wget zlib-devel openssl-devel
yum --disablerepo=mysql80-community --enablerepo=mysql57-community install mysql-community-libs-compat.x86_64
boost-devel.x86_64 mysql-community-devel
cd /usr/include/mysql
MYSQL_VERSION=$(rpm -qa | grep mysql-community-devel | awk -F'-' '{print $4}')
wget https://raw.githubusercontent.com/mysql/mysql-server/mysql-${MYSQL_VERSION}/include/hash.h
cd
git clone https://github.com/sysown/proxysql_mysqlbinlog.git
cd proxysql_mysqlbinlog
cd libslave/
cmake . && make
cd ..
ln -s /usr/lib64/mysql/libmysqlclient.a /usr/lib64/libmysqlclient.a
make
ProxySQL Features

31. © 2019 Percona31
Run
yum install epel-release
yum install boost-system
./proxysql_binlog_reader -h 127.0.0.1 -u root -psekret -P 3306 -l 3307 -L binlogreader.log
ProxySQL Features

32. © 2019 Percona32
PMM + ProxySQL + PXC
# ProxySQL
https://pmmdemo.percona.com/graph/d/fwWR9oiiz/proxysql-overview?refresh=1m&
orgId=1
#PXC
https://pmmdemo.percona.com/graph/d/s_k9wGNiz/pxc-galera-cluster-overview?refr
esh=1m&orgId=1

33. © 2019 Percona33
Questions?

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