Application in Mgr Review Should I Check on It or Not

April 18, 2022 Post a Comment

Community Weblog To MGR or Not MGR? Review of MySQL Group Replication

To MGR or Not MGR? Review of MySQL Grouping Replication

MGR is a highly available solution officially launched by MySQL. This article provides insights on the basics of MGR and Galera and ponders the questi.

Galera_to_be_phased_out_MySQL_Group_Replication_officially_launched

MySQL Grouping Replication GA

On December 12, 2016, Oracle released exciting news to the MySQL circle. Information technology officially launched version 5.seven.17 of MySQL, which includes the long-awaited MySQL Group Replication (MGR). This commodity provides insights on the nuts of MGR and Galera and ponders the question of whether or non MongoDB will become the next Galera.

What is MGR?

MGR is a highly bachelor solution officially launched past MySQL. It is based on the native replication technology and is available in the plug-in form. For those of yous non in the know, below are some of the main features of MGR:

●Backup and Modify Master for replication is no longer feasible. With MGR, the replication management operations are more automated.

●MGR uses the Paxos protocol and displays loftier data consistency amongst the database cluster node.

●All nodes among clusters can be replicated, which is the dream function of many developers. The inconvenience of information-writing operation of a single group is solved as MGR allows all nodes to be replicated.

●The split cluster effect caused past network segmentation is resolved which in plow upgrades the reliability of information replication.

Although MGR is besides known every bit the MySQL version of Oracle Real Awarding Clusters (RAC), there are architectural differences betwixt MGR and RAC. MGR shares nothing while Oracle RAC shares everything.

Diagram_1

What is Galera? Will be Phased Out

Galera is a multi-master cluster based on synchronous replication. It is an easy-to-use solution that offers scalability and data security.

Those familiar with Galera may come across similarities between MGR and Galera. Some companies and banks accept tried Galera's high availability solution for their production environments and accept encountered severe bug. Compared with Galera, MGR's advantages are:
●MGR is an official product past MySQL with guaranteed product control and subsequent technical back up.
●MGR works on the popular Paxos algorithm. This enables it to achieve optimal network performance and stability. The distributed peer-to-peer arrangement of MGR besides reduces overall latency. MGR supports nine nodes per group currently equally compared to Galera which supports only three nodes.
●MGR supports multiple operating system platforms, while Galera only supports the Linux system.

First, let's look at MGR's performance improvement in a multi-master node environment, namely conveying out read/write tests at multiple nodes at the aforementioned time:

Diagram_2

When the menstruum-command-mode parameter is disabled, i.eastward. when delay among cluster nodes is allowed, the MGR cluster performance tin can be elevated with the increase in the number of nodes. If information technology is configured to ensure reading consistency, the performance of an MGR cluster with five nodes is almost equivalent to that of a single MySQL instance.

Comparison Between MGR and Galera

The following figure compares MGR and Galera:

Diagram_3

Grouping Replication delivers more 80 percent of the throughput of asynchronous replication when durability is off. The touch on of the use of durability on Galera results in a larger overhead. It only achieves 30 percent asynchronous replication throughput.

Limitations of MGR

Although MySQL Group Replication provides high availability and a multi-master update everywhere in the replication solution, it even so has few limitations.
●MGR only supports InnoDB tables, and each tabular array must have a primary cardinal for conflict detection of write sets.
●The global transaction identifier (GTID) feature must be enabled, and the binary log format must exist set to ROW to select the master and write gear up.
●COMMIT may lead to a failure, which is similar to a snapshot failure scenario at the transaction isolation level.
●Currently, MGR supports a maximum of nine nodes.
●The strange central and relieve point features are not supported and global constraint detection and partial rollback cannot be carried out.
●The binary log is non compatible with binlog event checksum.

Volition MongoDB Become the Next Galera?

According to Oracle's electric current development roadmap, a distributed document database cluster will be created in the future. InsideMySQL is hoping for the GA of InnoDB Cluster in the time to come. The evolution of MGR brings it ane step closer. The more powerful MongoDB is a worthy rival for competition. In fact, it's worth waiting for a distributed document database based on MySQL, the most popular and stable option on the net, which supports transactions, row level locks, MultiVersion Concurrency Control (MVCC), and high data consistency.

References
ane.Zooming-in on Group Replication performance
2.Performance Evaluation: MySQL 5.7 Group Replication (GA Release)
three.InnoDB Cluster User Guide
four.http://galeracluster.com/products/
Original article: Galera to be phased out - MySQL Group Replication officially launched