Tips and tricks – how to shard mysql with proxysql in clustercontrol _ severalnines

Having too large a (write) workload on a master is dangerous. Tally erp 9 data recovery software If the master collapses and a failover happens to one of its slave nodes, the slave node could collapse under the write pressure as well. 7 databases in 7 weeks To mitigate this problem you can shard horizontally across more nodes.


Sharding increases the complexity of data storage though, and very often, it requires an overhaul of the application. 3 database models In some cases, it may be impossible to make changes to an application. Database programmer salary Luckily there is a simpler solution: functional sharding. Database developer salary With functional sharding you move a schema or table to another master, and thus alleviating the master from the workload of these schemas or tables.

In this Tips & Tricks post, we will explain how you can functionally shard your existing master, and offload some workload to another master using functional sharding. Data recovery agent We will use ClusterControl, MySQL replication and ProxySQL to make this happen, and the total time taken should not be longer than 15 minutes in total. Data recovery usb flash drive Mission impossible? 🙂 The example database

In our example we have a serious issue with the workload on our simple order database, accessed by the so_user. Data recovery windows The majority of the writes are happening on two tables: orders and order_status_log. Database definition Every change to an order will write to both the order table and the status log table.

After ProxySQL has been deployed we can connect with it via command line, and see it’s current configured servers and settings: MySQL [(none)]> select hostgroup_id, hostname, port, status, comment from mysql_servers;

+————–+————-+——+——–+———————–+ MySQL [(none)]> select rule_id, active, username, schemaname, match_pattern, destination_hostgroup from mysql_query_rules;

As you can see, ProxySQL has been configured with the ClusterControl default read/write splitter for our first cluster. Data recovery definition Any basic select query will be routed to hostgroup 20 (read pool) while all other queries will be routed to hostgroup 10 (master). Database or database What is missing here is the information about the second cluster, so we will add the hosts of the second cluster first: MySQL [(none)]> INSERT INTO mysql_servers VALUES (30, ‘10.10.36.13’, 3306, ‘ONLINE’, 1, 0, 100, 10, 0, 0, ‘Second repl setup read server’), (30, ‘10.10.36.14’, 3306, ‘ONLINE’, 1, 0, 100, 10, 0, 0, ‘Second repl setup read server’);

Query OK, 2 rows affected (0.00 sec) MySQL [(none)]> INSERT INTO mysql_servers VALUES (40, ‘10.10.36.13’, 3306, ‘ONLINE’, 1, 0, 100, 10, 0, 0, ‘Second repl setup read and write server’);

After this we need to load the servers to ProxySQL runtime tables and store the configuration to disk: MySQL [(none)]> LOAD MYSQL SERVERS TO RUNTIME;

As ProxySQL is doing the authentication for the clients as well, we need to add the os_user user to ProxySQL to allow the application to connect through ProxySQL: MySQL [(none)]> INSERT INTO mysql_users (username, password, active, default_hostgroup, default_schema) VALUES (‘so_user’, ‘so_pass’, 1, 10, ‘simple_orders’);

Now we have added the second cluster and user to ProxySQL. Data recovery software windows Keep in mind that normally in ClusterControl the two clusters are considered two separate entities. Cost of data recovery ProxySQL will remain part of the first cluster. Database first entity framework Even though it is now configured for the second cluster, it will only be displayed under the first cluster,. Data recovery iphone 5 Mirroring the data

Keep in mind that mirroring queries in ProxySQL is still a beta feature, and it doesn’t guarantee the mirrored queries will actually be executed. Raid 0 data recovery We have found it working fine within the boundaries of this use case. 7 data recovery serial key Also there are (better) alternatives to our example here, where you would make use of a restored backup on the new cluster and replicate from the master until you make the switch. Database modeling We will describe this scenario in a follow up Tips & Tricks blog post.

Now that we have added the second cluster, we need to create the simple_orders database, the order_status_log table and the appropriate users on the master of the second cluster: mysql> create database simple_orders;

This enables us to start mirroring the queries executed against the first cluster onto the second cluster. A database record is an entry that contains This requires an additional query rule to be defined in ProxySQL: MySQL [(none)]> INSERT INTO mysql_query_rules (rule_id, active, username, schemaname, match_pattern, destination_hostgroup, mirror_hostgroup, apply) VALUES (50, 1, ‘so_user’, ‘simple_orders’, ‘(^INSERT INTO|^REPLACE INTO|^UPDATE|INTO TABLE) order_status_log’, 20, 40, 1);

In this rule ProxySQL will match everything that is writing to the orders_status_log table, and send it in addition to the hostgroup 40. Java database (write server of the second cluster)

Now that we have started mirroring the queries, the backfill of the data from the first cluster can take place. Easeus data recovery 9 serial You can use the timestamp from the first entry in the new orders_status_log table to determine the time we started to mirror.

Once the data has been backfilled we can reconfigure ProxySQL to perform all actions on the orders_status_log table on the second cluster. Iphone 5 data recovery software free This will be a two step approach: add a new rule to move the read queries to the second cluster’s read servers and except the SELECT … FOR UPDATE queries. Database partitioning Then another one to modify our mirroring query to stop mirroring and only write to the second cluster. Database gif MySQL [(none)]> INSERT INTO mysql_query_rules (rule_id, active, username, schemaname, match_pattern, destination_hostgroup, apply) VALUES (70, 1, ‘so_user’, ‘simple_orders’, ‘^SELECT .* FROM order_status_log’, 30, 1), (60, 1, ‘so_user’, ‘simple_orders’, ‘^FROM order_status_log .* FOR UPDATE’, 40, 1);

Query OK, 2 rows affected (0.00 sec) MySQL [(none)]> UPDATE mysql_query_rules SET destination_hostgroup=40, mirror_hostgroup=NULL WHERE rule_id=50;

After this final step we should see the workload drop on the first cluster, and increase on the second cluster. Database project ideas Mission possible and accomplished. Iphone 5 data recovery without backup Happy clustering!

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