Tungsten Replicator 4.0.6 is a bugfix release that contains critical fixes and improvements to the Tungsten Replicator 4.0.5 release.
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:
The following issues may affect the operation of Tungsten Replicator and should be taken into account when deploying or updating to this release.
There is a limit in the communication protocal for the replicator which limits the number of fragments within a single transaction in the THL to 32768. Although this is not a limit in the THL format, it is a limit in the protocol used to exchanged the THL information between replicators.
The size of this value, and therefore, the maximum number of fragments cannot be increased without creating an incompatible change within the replicator. This creates a limit to the maximum size of a single transaction that can be replicated. Although this figure cannot be altered, the size of each individual fragment can be increased. The default setting is 1,000,000, creating a limit of approximately 32GB.
To increase the fragment size, set the value of the property
replicator.extractor.dbms.transaction_frag_size. For example, increasing the value to 2,000,000 would increase the maximum THL transaction size to approximately 64GB.
Care should be taken when increasing this value, as it also increases the amount of memory required to handle the transaction.
There is a known issue with the
fixmysqlstrings.jsfilter. When translating
Due to changes in the datatypes available in MySQL 5.7 and the supported datatypes within Tungsten Replicator, and coinciding with changes to the way this information is available, the tpm checks for compatibility may no longer highlight important option changes. For example, virtual columns and JSON columns in MySQL 5.7 are not replicated. During installation, if tpm identifies that MySQL 5.7 is in use, the following message will be reported:
IMPORTANT: The replicator is unable to replicate tables that have columns defined as type JSON or that utilise VIRTUAL GENERATED values! The use of these features will cause replication to fail. If you want tpm to check for these add --mysql-allow-intensive-checks to the configuration. Be aware that the checks will query the information_schema and if you have thousands of tables this may affect other queries while the check runs. Otherwise, if you have confirmed manually that JSON or VIRTUAL GENERATED columns are not being used, you can skip this check by adding --skip-validation-check=MySQLUnsopportedDataTypesCheck to your configuration.
To address this issue, when using tpm during
an installation, more intensive checks for tables with
unsupported types can be performed. For example, when checking
the special column types used in all tables within an existing
installation, tpm must check each table
individually. As this can increase the load on the server during
installagtion, tpm by default does not
perform these checks. Instead, these checks can be enabled by
option during configuration. Enabling this option provides for a
much more detailed check, but may cause the installation process
to take longer.
Issues: CONT-1551, CONT-1576