3.2. Special Considerations for Existing Customers


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3.2. Special Considerations for Existing Customers

Most of the new features and capabilities in Volt V8.0 do not impact existing applications. However, there are a few changes that do require minor changes to the configuration when upgrading from earlier versions. Existing customers should take note of of the following changes:

  • Change to default Kafka versions for import

    For the kafka import connector and the kafkaloader command line utility, the default Kafka version has changed from 0.8.2 to 0.10.2 or later. For customers already using Kafka 0.10.2 or later, there are no changes needed to their configuration, scripts, or applications. For customers who wish to continue using the older Kafka version 0.8.2, they will need to add the attribute version="8" to the import connector configuration and/or use the command line utility kafkaloader8 instead of the default kafkaloader.

  • The "elastic" attribute removed from <cluster>

    An artifact of an old feature provided for backwards compatibility, the elastic attribute of the <cluster> element in the configuration file was disabled and deprecated several years ago. It has now been removed. Although it is unlikely any still exist, configuration files that do include this attribute will now fail to parse. Simply remove the attribute and try again.

  • The <consistency> element removed from the configuration file

    The <consistency> element was recently deprecated, since "fast" read consistency no longer provides any significant performance improvement over "safe" mode but does introduce potential risks during failure scenarios. It has now been removed from the allowable configuration file syntax. If you included <consistency> in your configuration file, please remove it before starting a Volt 8.0 cluster.

  • Old commands for starting Volt are no longer supported

    Volt 6.6 introduced two new integrated commands, init and start, for starting Volt servers. At that time the old commands (add, create, recover, and rejoin) were deprecated. The old commands have now been removed from the product. If you still use the older commands, please update your scripts to use the new commands as described in the chapter "Starting the Database" in the Using VoltDB manual.