1.13. Tungsten Clustering 6.0.0 GA (4 April 2018)

Version End of Life. 31 July 2020

Tungsten Cluster 6.0.0 is a major update to the operation and deployment of composite clusters. Within the new framework, a Composite Active/Active cluster is configured as follows:

  • Clusters within a composite cluster are now managed in a unified fashion, including the overall replication progress across clusters.

  • Cross-site replicators are configured as additional services within the main replicator.

  • Cross-site replicators are managed by the manager as part of a complete composite cluster solution.

  • A new global progress counter displays the current progress for the local and cross-site replication.

  • Connectors are configured by default to provide affinity for the local, and then the remote cluster.

The cluster package name has been changed, and upgrades from older versions to the new configuration and layout are supported.

Behavior Changes

The following changes have been made to Tungsten Cluster and may affect existing scripts and integration tools. Any scripts or environment which make use of these tools should check and update for the new configuration:

  • Installation and Deployment

    • A new unified cluster deployment is available, the Composite Active/Active. This is an updated version of the Multi-Site/Active-Active deployment in previous releases. It encompasses a number of significant changes and improvements:

      • Single, cluster-based, deployment using the new deployment type of composite-multi-master.

      • Unified Composite Active/Active cluster status within cctrl (in [Tungsten Clustering (for MySQL) 6.0 Manual]).

      • Global progress counter indiciting the current cluster and cross-cluster performance.

      Issues: CT-105, CT-313, CT-431, CT-467

    • The name of the cluster deployment package for Tungsten Cluster has changed. Packages are now named to match the product, for example, release-notes-1-99.tar.gz.

      Issues: CT-271, CT-438

    • Support for using Java 7 with Tungsten Cluster has been removed. Java 8 or higher must be used for all deployments.

      Issues: CT-450

    • The behavior of the cctrl (in [Tungsten Clustering (for MySQL) 6.0 Manual]) has changed to operate better within the new composite deployments. Without the -multi (in [Tungsten Clustering (for MySQL) 6.0 Manual]) argument, cctrl (in [Tungsten Clustering (for MySQL) 6.0 Manual]) will cd (in [Tungsten Clustering (for MySQL) 6.0 Manual]) into the local standalone service. This matches the previous releases for cctrl (in [Tungsten Clustering (for MySQL) 6.0 Manual]), but instead all services are still accessible without needing to use the -multi (in [Tungsten Clustering (for MySQL) 6.0 Manual]) option. With the -multi (in [Tungsten Clustering (for MySQL) 6.0 Manual]) argument, cctrl (in [Tungsten Clustering (for MySQL) 6.0 Manual]) will not automatically cd (in [Tungsten Clustering (for MySQL) 6.0 Manual]) into the local standalone service but will show all available services.

      Issues: CT-524

  • Command-line Tools

    • Due to the change in the nature of the services and clustering within Composite Active/Passive and Composite Active/Active configurations, the tungsten_provision_slave (in [Tungsten Clustering (for MySQL) 6.0 Manual]) command has been updated to support cross-cluster provisioning. Because there would now be a conflict of service names, a cross cluster provision should use the --force (in [Tungsten Clustering (for MySQL) 6.0 Manual]) option. The --service (in [Tungsten Clustering (for MySQL) 6.0 Manual]) option should still be set to the local service being reset. For example:

      shell> tungsten_provision_slave --source=db4 --service=east --direct --force

      Issues: CT-567

Known Issue

The following issues may affect the operation of Tungsten Cluster and should be taken into account when deploying or updating to this release.

  • Installation and Deployment

    • During an upgrade installation from a v4 or v4 MSMM deployment, you may get additional, empty, schemas creates within your MySQL database. These schemas are harmless and can safely be removed. For example, if you have two services in your MSMM deployment, east and west, during the upgrade you will get two empty schemas, tungsten_east_from_west and tungsten_west_from_east.

      This will be addressed in a future release.

      Issues: CT-559

    • When performing a tpm update (in [Tungsten Clustering (for MySQL) 6.0 Manual]) operation to change the configuration and the cluster is in AUTOMATIC (in [Tungsten Clustering (for MySQL) 6.0 Manual]) mode, the update will complete correctly but the cluster may be left in MAINTENANCE (in [Tungsten Clustering (for MySQL) 6.0 Manual]) mode instead of being placed back into AUTOMATIC (in [Tungsten Clustering (for MySQL) 6.0 Manual]) mode.

      This will be addressed in a future release.

      Issues: CT-595

    • When performing a tpm update (in [Tungsten Clustering (for MySQL) 6.0 Manual]) in a cluster with an active witness, the host with the witness will not be restarted correctly resulting in the witness being down on that host.

      This will be addressed in a future release.

      Issues: CT-596

    • In a Composite Active/Active cluster deployment where there are three or more clusters, a failure in the MySQL server in one node in a clsuter could fail to be identified, and ultimately the failover within the environment to fail, either within the cluster or across clusters.

      This will be addressed in a future release.

      Issues: CT-619

  • Tungsten Manager

    • During a switch operation on a Composite Active/Active cluster when the cluster has been put into maintenance mode, the manager will put the cross-site replicators back into the online state.

      This will be addressed in a future release.

      Issues: CT-591

Improvements, new features and functionality

  • Installation and Deployment

    • A new utility script, tungsten_prep_upgrade (in [Tungsten Clustering (for MySQL) 6.0 Manual]) has been provided as part of the standard installation. The script is specifically designed to assist during the upgrade of a Multi-Site/Active-Active deployment from 5.3.0 and earlier to the new Composite Active/Active 6.0.0 deployment.

      Issues: CT-104

  • Command-line Tools

    • The cctrl (in [Tungsten Clustering (for MySQL) 6.0 Manual]) command now includes a show topology (in [Tungsten Clustering (for MySQL) 6.0 Manual]) command, that outputs the current toplogy for the cluster or component being viewed.

      Issues: CT-429

    • The tpm diag (in [Tungsten Clustering (for MySQL) 6.0 Manual]) command has been extended to include Composite Active/Active cluster status information, one for each configured service and cross-site service.

      Issues: CT-594

  • Tungsten Connector

    • By default, within Composite Active/Active clusters, the affinity for the connector is configured to connect to the Primary for the site on which the connector lives first and then, if that Primary is not available, connect to the other site

      Issues: CT-448

Bug Fixes

  • Command-line Tools

    • The mm_tpm diag command could complain that an extra replicator is configured and running, even though it would be valid as part of a Composite Active/Active deployment.

      Issues: CT-396

    • The mm_trepctl (in [Tungsten Clustering (for MySQL) 6.0 Manual]) command could fail to display any status information while obtaining the core statistic information from each host.

      Issues: CT-437

  • Tungsten Manager

    • When performing a recover or switch operation within maintenance mode, the cluster would automatically revert to automatic mode just before and immediately after a switch, which could lead to problems correctly recovering a cluster.

      Issues: CT-472

Tungsten Clustering 6.0.0 Includes the following changes made in Tungsten Replicator 6.0.0

Release 6.0.0 is a feature and bugfix release. This release contains the following key fixes:

  • Added PostgreSQL applier support.

  • Added support for custom primary key field selection for source tables that cannot be configured with a primary key within the database.

  • Added a new filter for including whole of transaction metadata information into each event.

  • Added support for extended transaction information within the Kafka applier so that all the messages for a given transaction can be identified.

Behavior Changes

The following changes have been made to Tungsten Replicator and may affect existing scripts and integration tools. Any scripts or environment which make use of these tools should check and update for the new configuration:

Improvements, new features and functionality

  • Heterogeneous Replication

    • The Kafka applier now supports the inclusion of transaction information into each Kafka message broadcast, including the list of schema/tables and row counts for the entire transaction, as well as information about whether the message is the first or last message/row within an overall transaction. The transaction information can also be sent as a separate message on an independent Kafka topic.

      Issues: CT-496, CT-586

      For more information, see Optional Configuration Parameters for Kafka (in [Tungsten Replicator 6.0 Manual]).

  • Core Replicator

    • Experimental support for writing row-based data through SQL into PostgreSQL has been added back to the replicator. This includes basic support fr the replication of the data. Currently databases and tables must be created by hand. A future release will incorporate full support for DDL translation.

      Issues: CT-149

  • Filters

    • The pkey (in [Tungsten Replicator 7.0 Manual]) has been extended to support the specification of custom primary key fields. This enables fields in the source data to be marked as primary keys even if the source database does not have the keys specified. This is useful for heterogeneous loading of data where a unique key may exist, but cannot be defined due to the application or database that created the tables.

      Issues: CT-481

    • A new filter, rowaddtxninfo (in [Tungsten Replicator 7.0 Manual]) has been added which embeds row counts, both total and per schema/table, to the metadata for a THL event/transaction.

      Issues: CT-497

Bug Fixes

  • Installation and Deployment

    • When performing a tpm reverse (in [Tungsten Replicator 6.0 Manual]), the --replication-port (in [Tungsten Replicator 6.0 Manual]) setting would be replaced with it's alias, --oracle-tns-port.

      Issues: CT-597

  • Core Replicator

    • An internal optimization within the replicator that would attempt to optimise row-based information and operations has been removed. The effects of the optimization were actually seen in very few situations, and it duplicated work and operations performed by the pkey (in [Tungsten Replicator 7.0 Manual]) filter. Unfortunately the same optimization could also cause issues within heterogeneous deployments with the removal of information.

      Issues: CT-318

    • The internal storage of the MySQL server ID has been updated to support larger server IDs. This works with any MySQL deployment, but has been specifically expanded to work better with some cloud deployments where the server ID cannot be controlled.

      Issues: CT-439

    • The format of some errors and log entries would contain invalid characters.

      Issues: CT-493