Java driver 4.0.0-alpha2

[Olivier Michallat]

We've just released the second developer preview of our 4.0 driver.

This version exposes the full set of cluster metadata (JAVA-1493, JAVA-1525). Contrary to 3.x, metadata is now updated atomically, which means the node list, schema and token map will always be in sync for a given Metadata instance. In addition, you can enable/disable the schema and token map independently and filter out keyspaces, and we've improved the token map computation algorithm.

Another nice improvement is JAVA-1295, which revisits native protocol negotiation in a mixed-version cluster: after the first connection, the driver will now downgrade automatically if it detects nodes that don't support the current protocol version; you no longer need to force it or worry about providing the right contact points (for reference, here's the relevant section in the 3.3 manual, which describes the problems that are now solved).

Apart from that, this release migrates a few other missing features, and fixes a couple of bugs around node states.

Here is the full changelog:

- [new feature] JAVA-1525: Handle token metadata

- [new feature] JAVA-1638: Check schema agreement

- [new feature] JAVA-1494: Implement Snappy and LZ4 compression

- [new feature] JAVA-1514: Port Uuids utility class

- [new feature] JAVA-1520: Add node state listeners

- [new feature] JAVA-1493: Handle schema metadata

- [improvement] JAVA-1605: Refactor request execution model

- [improvement] JAVA-1597: Fix raw usages of Statement

- [improvement] JAVA-1542: Enable JaCoCo code coverage

- [improvement] JAVA-1295: Auto-detect best protocol version in mixed cluster

- [bug] JAVA-1565: Mark node down when it loses its last connection and was already reconnecting

- [bug] JAVA-1594: Don't create pool if node comes back up but is ignored

- [bug] JAVA-1593: Reconnect control connection if current node is removed, forced down or ignored

- [bug] JAVA-1595: Don't use system.local.rpc_address when refreshing node list

- [bug] JAVA-1568: Handle Reconnection#reconnectNow/stop while the current attempt is still in 

  progress

- [improvement] JAVA-1585: Add GenericType#where

- [improvement] JAVA-1590: Properly skip deployment of integration-tests module

- [improvement] JAVA-1576: Expose AsyncResultSet's iterator through a currentPage() method

- [improvement] JAVA-1591: Add programmatic way to get driver version

As usual, the driver is available from Maven:

<dependency>

  <groupId>com.datastax.oss</groupId>

  <artifactId>java-driver-core</artifactId>

  <version>4.0.0-alpha2</version>

</dependency>

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The Java driver team