CNDB-9821 Lock-free RequestSensors#syncAllSensors implementation

[aymkhalil]

Addresses: https://github.com/riptano/cndb/issues/9821

This is another proposal (see https://github.com/datastax/cassandra/pull/1156) to implement a lock-free RequestSensors#syncAllSensors. The sensor changes are anti-pattern but maybe justified for optimization purposes. This patch alleviates the need of ReadWrite locks and the in memory sensors value snapshots.

The benchmark results are:

Benchmark                            Mode  Cnt      Score      Error  Units
RequestSensorsBench.syncAllSensors  thrpt    5  48446.429 ± 7200.384  ops/s

vs.

Benchmark                            Mode  Cnt     Score     Error  Units
RequestSensorsBench.syncAllSensors  thrpt    5  8978.558 ± 674.063  ops/s

without this patch. Note that the improvements from https://github.com/datastax/cassandra/pull/1156.

[sonarqubecloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[niksajakovljevic]

I am not sure we can trust this benchmark mainly because SensorRegistry is not incrementing (returning empty sensor) unless we populate keyspace and tableId in the setup

[aymkhalil]

Closed in favor of https://github.com/datastax/cassandra/pull/1184