Suboptimal queries on Session/Connection initiation in version 4.17

[Foxlik]

While looking into performance issues in one of our clusters I've noticed that the v4.17 Java driver does uses some sub-optimal queries on connecting to the cluster:

java-driver/core/src/main/java/com/datastax/oss/driver/internal/core/channel/ProtocolInitHandler.java

Line 83 in d33dbc5

new Query("SELECT cluster_name FROM system.local");

java-driver/core/src/main/java/com/datastax/oss/driver/internal/core/metadata/DefaultTopologyMonitor.java

Line 171 in d33dbc5

CompletionStage<AdminResult> localQuery = query(channel, "SELECT * FROM system.local");

Both of these queries force full table scan as there's no key reference. I've tried appending WHERE key = 'local' to these queries and as a result the Session creation got about 90 % faster in the troubled cluster case. (YMMV)

This seems to be fixed in the 3.x version of the driver.

java-driver/driver-core/src/main/java/com/datastax/driver/core/ControlConnection.java

Line 79 in 9fe1e03

private static final String SELECT_LOCAL = "SELECT * FROM system.local WHERE key='local'";

Looks related to this issue.

[mykaul]

Seems to be the same as in upstream (https://github.com/apache/cassandra-java-driver/blob/388a46b9c10b5653c71ac8840bcda0c91b59bce4/core/src/main/java/com/datastax/oss/driver/internal/core/channel/ProtocolInitHandler.java#L72 for example)