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Percona XtraDB Cluster 8.0.26-16.1
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    • Home
      • About Percona XtraDB Cluster
      • Percona XtraDB Cluster limitations
      • Understand version numbers
      • Quick start guide for Percona XtraDB Cluster
      • Install Percona XtraDB Cluster
      • Configure nodes for write-set replication
      • Bootstrap the first node
      • Add nodes to cluster
      • Verify replication
      • High availability
      • PXC strict mode
      • Online schema upgrade
      • Non-Blocking Operations (NBO) method for Online Scheme Upgrades (OSU)
      • Security basics
      • Secure the network
      • Encrypt PXC traffic
      • Enable AppArmor
      • Enable SELinux
      • State snapshot transfer
      • Percona XtraBackup SST configuration
      • Restart the cluster nodes
      • Cluster failover
      • Monitor the cluster
      • Certification in Percona XtraDB Cluster
      • Percona XtraDB Cluster threading model
      • Understand GCache and Record-Set cache
      • GCache encryption and Write-Set cache encryption
      • Perfomance Schema instrumentation
      • Data at Rest Encryption
      • Upgrade Percona XtraDB Cluster
      • Crash recovery
      • Configure Percona XtraDB Cluster on CentOS
      • Configure Percona XtraDB Cluster on Ubuntu
      • Set up Galera arbitrator
      • How to set up a three-node cluster on a single box
      • How to set up a three-node cluster in EC2 environment
      • Load balancing with HAProxy
      • Load balancing with ProxySQL
      • ProxySQL admin utilities
      • Setting up a testing environment with ProxySQL
      • Release notes index
      • Percona XtraDB Cluster 8.0.31-23 (2023-03-14)
      • Percona XtraDB Cluster 8.0.30-22.md (2022-12-28)
      • Percona XtraDB Cluster 8.0.29-21 (2022-09-12)
      • Percona XtraDB Cluster 8.0.28-19.1 (2022-07-19)
      • Percona XtraDB Cluster 8.0.27-18.1
      • Percona XtraDB Cluster 8.0.26-16.1
        • Release Highlights
        • Bugs Fixed
        • Known Issues (unfixed problems that you should be aware of)
      • Percona XtraDB Cluster 8.0.25-15.1
      • Percona XtraDB Cluster 8.0.23-14.1
      • Percona XtraDB Cluster 8.0.22-13.1
      • Percona XtraDB Cluster 8.0.21-12.1
      • Percona XtraDB Cluster 8.0.20-11
      • Percona XtraDB Cluster 8.0.20-11.3
      • Percona XtraDB Cluster 8.0.20-11.2
      • Percona XtraDB Cluster 8.0.19-10
      • Percona XtraDB Cluster 8.0.18-9.3
      • Index of wsrep status variables
      • Index of wsrep system variables
      • Index of wsrep_provider options
      • Index of files created by PXC
      • Frequently asked questions
      • Glossary
      • Copyright and licensing information
      • Trademark policy

    • Release Highlights
    • Bugs Fixed
    • Known Issues (unfixed problems that you should be aware of)

    Percona XtraDB Cluster 8.0.26-16.1¶

    • Date

      January 17, 2022

    • Installation

      Installing Percona XtraDB Cluster

    Percona XtraDB Cluster (PXC) supports critical business applications in your public, private, or hybrid cloud environment. Our free, open source, enterprise-grade solution includes the high availability and security features your business requires to meet your customer expectations and business goals.

    Release Highlights¶

    The following are a number of the notable fixes for MySQL 8.0.26, provided by Oracle, and included in this release:

    • The TLSv1 and TLSv1.1 connection protocols are deprecated.

    • Identifiers with specific terms, such as “master” or “slave” are deprecated and replaced. See the Functionality Added or Changed section in the 8.0.26 Release Notes for a list of updated identifiers. The following terms have been changed:

    • The identifier master is changed to source

    • The identifier slave is changed to replica

    • The identifier multithreaded slave (mts) is changed to multithreaded applier (mta)

    • When using semisynchronous replication, either the old version or the new version of system variables and status variables are available. You cannot have both versions installed on an instance. The old system variables are available when you use the old version, but the new ones are not. The new system variables are available when you use the new version, but the old values are not.

    In an upgrade from an earlier version to 8.0.26, enable the rpl_semi_sync_source plugin and the rpl_semi_sync_replica plugin after the upgrade has been completed. Enabling these plugins before all of the nodes are upgraded may cause data inconsistency between the nodes.

    For the source, the rpl_semi_sync_master plugin (seminsync_master.so library) is the old version and the rpl_semi_sync_source plugin(semisync_source.so library) is the new version.

    For the client, the rpl_semi_sync_slave plugin (semisync_slave.so library) is the old version and the rpl_semi_sync_replica plugin (semisync_replica.so library) is the new version

    For more information, see the MySQL 8.0.26 Release Notes.

    Bugs Fixed¶

    • PXC-3824: An incorrect directive in Systemd Unit File (Thanks to Jim Lohiser for reporting this issue)

    • PXC-3706: A fix for a race condition in group commit queue (Thanks to Kevin Sauter for reporting this issue)

    • PXC-3739: The FLUSH TABLES FOR EXPORT lock is released when the session ends.

    • PXC-3628: The server allowed altering the storage engine to MyISAM for mysql.wsrep_* tables.

    • PXC-3731: A fix for when the user deletes data from the source but does not want that data deleted from the replica. The sql_log_bin=0 command had no effect and the deleted rows were replicated and written into the binary log.

    • PXC-3857: The following system variables are renamed. The old variables are deprecated and may be removed in a future version.

    • wsrep_slave_threads renamed as wsrep_applier_threads

    • wsrep_slave_FK_checks renamed as wsrep_applier_FK_checks

    • wsrep_slave_UK_checks renamed as wsrep_applier_UK_checks

    • wsrep_restart_slave renamed as wsrep_restart_replica

    Known Issues (unfixed problems that you should be aware of)¶

    • PXC-3039: No useful error messages if an SSL-disabled node tried to join an SSL-enabled cluster

    • PXC-3093: A completed SST Transfer is incorrectly logged by garbd. The timing is incorrect.

    Contact us

    For free technical help, visit the Percona Community Forum.

    To report bugs or submit feature requests, open a JIRA ticket.

    For paid support and managed or consulting services , contact Percona Sales.


    Last update: 2023-01-20
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