With the release of version 8.0.16 of MySQL, we’ve added some features to the Group Replication (GR) plugin, in order to enhance its high-availability capacities. One of these features was the ability to enable a member that has left the group, under certain circumstances, to automatically rejoin it, without need of intervention by the user.…
Category Archives: Group Replication
Configuring the communication protocol in Group Replication
In a previous blog post we presented the message fragmentation functionality that you can use starting with MySQL Group Replication 8.0.16.
No group member can have a version < 8.0.16 if you wish to use message fragmentation in a group. MySQL 8.0.16 also ships with a new Group Replication concept to help you ensuring backwards compatibility: the group’s communication protocol.…
Enhanced support for large transactions in Group Replication
MySQL 8.0.16 is out and it enhances Group Replication as usual. For example, the group_replication_exit_state_action system variable has a new default value, and members that the group expels can now automatically try to rejoin. This post presents a new feature MySQL 8.0.16 brings to Group Replication: message fragmentation.…
MySQL 8.0.16 Replication Enhancements
MySQL 8.0.16 has been released last Thursday. In it, you can find some new replication features. Here is a quick summary. Follow-up blog posts will provide details about these features.
- Large Messages Fragmentation Layer for Group Replication. Tiago Vale’s work, introduces message fragmentation to the Group Communication Framework.
Group Replication – Consistent Reads Deep Dive
On previous posts about Group Replication consistency we:
- introduced consistency levels;
- explained how to configure the primary failover consistency;
- presented how to configure transaction consistency levels to achieve the consistency required by your applications.
In blog 3. we presented the consistency levels: EVENTUAL, BEFORE, AFTER and BEFORE_AND_AFTER; their scopes: SESSION, GLOBAL; and their context: whether they only impact the ongoing transaction or all concurrent transactions.…
IPv6 support in Group Replication
In 8.0.14, we add to Group Replication (GR) the ability to use IPv6 in all of its network-related configuration parameters. This means that now you can take advantage of this technology and “rock” those billion addresses using MySQL Group Replication.
What’s New
When you operate a Group Replication group, some variables use network addresses, mainly:
- group_replication_local_address;
- group_replication_ip_whitelist
- group_replication_group_seeds;
- group_replication_force_members.
Fail early, fail fast – preventing stale reads on a member that dropped out of the group!
In Group Replication, starting with MySQL 8.0.12, the user is able to specify the behavior for members that enter an error state. The member can either shoot itself on the head or set itself to read-only.
But what does that mean in practice?…
Group Replication – Consistent Reads
As we showed on the introduction post, in MySQL 8.0.14 Group Replication was once again improved. Now the developer can specify which is the consistency level of all group transactions or even of a single transaction.
Note that this is about consistency in terms of the global synchronization of transactions in the group.…
Group Replication now interacts with the Group Communication Engine more efficiently
MySQL 8.0.14 comes with a plethora of new features. Some of the new Group Replication features have user–facing options, some impact user-facing options, and others stay completely under the hood. This post will present one of the under-the-hood changes in MySQL 8.0.14: the way the Group Replication layer interacts with the underlying Group Communication Engine layer, XCom.…
Group Replication: Preventing stale reads on primary fail-over!
This is a follow up post about the new consistency option of Group Replication group_replication_consistency. We recommend that you first read this post to get an overview of scenarios that can be addressed with this solution.
A group replication cluster will automatically detect failures and adjust the view of the members that are active, i.e., the membership configuration.…