fix: arrow BaseAllocator is reporting memory leaks (#306)

* fix: (WIP) ensure FlightStream is closed properly to avoid BaseAllocator memory leaks.

* chore: remove unused imports in E2E test

* fix: additional workaround for closing FlightStream and test update.

* chore: free references to unused FlightStreams to help GC

* chore: clean up lint issues

* test: add test of FlightStream overhead.

* test: fix flakey test for FlightStream overhead.

* docs: update CHANGELOG.md

* chore: cleanup flightStream ledger of FlightSqlClient close.

* test: suppress assertion that makes test flakey in CI.

* chore: remove static LEDGER field from FlightSqlClient

* fix: remove List<autocloseable> from FlightSqlClient and simplify closing FlightStream.

* chore: fix lint issues

* docs: remove no-longer pertinent information from CHANGELOG.md

* tests: restore logging in E2E test.

* chore: attempt SNAPSHOT publish

* chore: revert SNAPSHOT version and CI config - snapshot was deployed.

Author: karel-rehor

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## 1.6.0 [unreleased]
 
+### Features
+
+1. [#306](https://github.com/InfluxCommunity/influxdb3-java/pull/306): Improve closing of Arrow `FlightStream`.
+
 ## 1.5.0 [2025-10-22]
 
 ### Features

src/main/java/com/influxdb/v3/client/internal/FlightSqlClient.java

@@ -271,6 +271,7 @@ public VectorSchemaRoot next() {
         @Override
         public void close() {
             try {
+                flightStream.close();
                 AutoCloseables.close(autoCloseable);
             } catch (Exception e) {
                 throw new RuntimeException(e);

src/test/java/com/influxdb/v3/client/integration/E2ETest.java

@@ -26,6 +26,7 @@
 import java.net.URL;
 import java.net.URLConnection;
 import java.time.Instant;
+import java.time.temporal.ChronoUnit;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -52,7 +53,7 @@
 
 public class E2ETest {
 
-    private static final java.util.logging.Logger LOG = Logger.getLogger(E2ETest.class.getName());
+    private static final Logger LOG = Logger.getLogger(E2ETest.class.getName());
 
     @EnabledIfEnvironmentVariable(named = "TESTING_INFLUXDB_URL", matches = ".*")
     @EnabledIfEnvironmentVariable(named = "TESTING_INFLUXDB_TOKEN", matches = ".*")
@@ -381,6 +382,109 @@ public void testGetServerVersion() throws Exception {
         }
     }
 
+    @EnabledIfEnvironmentVariable(named = "TESTING_INFLUXDB_URL", matches = ".*")
+    @EnabledIfEnvironmentVariable(named = "TESTING_INFLUXDB_TOKEN", matches = ".*")
+    @EnabledIfEnvironmentVariable(named = "TESTING_INFLUXDB_DATABASE", matches = ".*")
+    @Test
+    public void testNoAllocatorMemoryLeak() {
+
+        Instant now = Instant.now();
+        String measurement = "test_" + now.toEpochMilli() % 1000;
+
+        Assertions.assertThatNoException().isThrownBy(() -> {
+
+            try (InfluxDBClient client = InfluxDBClient.getInstance(
+                System.getenv("TESTING_INFLUXDB_URL"),
+                System.getenv("TESTING_INFLUXDB_TOKEN").toCharArray(),
+                System.getenv("TESTING_INFLUXDB_DATABASE"),
+                null)) {
+
+                List<Point> points = List.of(
+                    Point.measurement(measurement)
+                        .setTag("type", "test")
+                        .setFloatField("rads", 3.14)
+                        .setIntegerField("life", 42)
+                        .setTimestamp(now.minus(2, ChronoUnit.SECONDS)),
+                    Point.measurement(measurement)
+                        .setTag("type", "test")
+                        .setFloatField("rads", 3.14)
+                        .setIntegerField("life", 42)
+                        .setTimestamp(now.minus(1, ChronoUnit.SECONDS)),
+                    Point.measurement(measurement)
+                        .setTag("type", "test")
+                        .setFloatField("rads", 3.14)
+                        .setIntegerField("life", 42)
+                        .setTimestamp(now));
+
+                client.writePoints(points);
+                String query = "SELECT * FROM " + measurement;
+
+                try (Stream<PointValues> stream = client.queryPoints(query)) {
+                    // N.B. with other items remaining in the stream, an unclosed FlightStream
+                    // will not clean up the residual items and will cause the BaseAllocator
+                    // to throw an IllegalStateException: Memory was leaked...
+                    // Test to ensure FlightStream was closed even though two more records
+                    // remain in the stream
+                    stream.findFirst()
+                        .ifPresent(pointValues -> {
+                            Assertions.assertThat(pointValues.getField("life")).isEqualTo(42L);
+                            Assertions.assertThat(pointValues.getField("rads")).isEqualTo(3.14);
+                        });
+                }
+            }
+        });
+
+    }
+
+    @EnabledIfEnvironmentVariable(named = "TESTING_INFLUXDB_URL", matches = ".*")
+    @EnabledIfEnvironmentVariable(named = "TESTING_INFLUXDB_TOKEN", matches = ".*")
+    @EnabledIfEnvironmentVariable(named = "TESTING_INFLUXDB_DATABASE", matches = ".*")
+    @Test
+    public void testMultipleQueries() throws Exception {
+
+        Instant now = Instant.now();
+        String measurement = "test_" + now.toEpochMilli() % 1000;
+
+        try (InfluxDBClient client = InfluxDBClient.getInstance(
+            System.getenv("TESTING_INFLUXDB_URL"),
+            System.getenv("TESTING_INFLUXDB_TOKEN").toCharArray(),
+            System.getenv("TESTING_INFLUXDB_DATABASE"),
+            null)) {
+
+            List<Point> points = List.of(
+                Point.measurement(measurement)
+                    .setTag("type", "test")
+                    .setFloatField("rads", 3.14)
+                    .setIntegerField("life", 42)
+                    .setTimestamp(now.minus(2, ChronoUnit.SECONDS)),
+                Point.measurement(measurement)
+                    .setTag("type", "test")
+                    .setFloatField("rads", 3.14)
+                    .setIntegerField("life", 42)
+                    .setTimestamp(now.minus(1, ChronoUnit.SECONDS)),
+                Point.measurement(measurement)
+                    .setTag("type", "test")
+                    .setFloatField("rads", 3.14)
+                    .setIntegerField("life", 42)
+                    .setTimestamp(now));
+
+            client.writePoints(points);
+            String query = "SELECT * FROM " + measurement;
+
+            for (int i = 0; i < 20; i++) {
+                try (Stream<PointValues> stream = client.queryPoints(query)) {
+                    stream.forEach(pointValues -> {
+                        Assertions.assertThat(pointValues.getField("life")).isEqualTo(42L);
+                        Assertions.assertThat(pointValues.getField("rads")).isEqualTo(3.14);
+                    });
+                }
+            }
+        }
+
+
+    }
+
+
     private void assertGetDataSuccess(@Nonnull final InfluxDBClient influxDBClient) {
         influxDBClient.writePoint(
                 Point.measurement("test1")