fix: possible memory leak in query stream close

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## 1.7.0 [unreleased]
 
+### Bug Fixes
+
+1. [#317](https://github.com/InfluxCommunity/influxdb3-java/pull/317): Fix Arrow memory leak when stream close fails due to thread interrupts.
+
 ## 1.6.0 [2025-11-14]
 
 ### Features

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

@@ -270,11 +270,43 @@ public VectorSchemaRoot next() {
 
         @Override
         public void close() {
+            Exception pendingException = null;
+
+            // Try to close FlightStream
             try {
                 flightStream.close();
+            } catch (Exception e) {
+                LOG.warn("FlightStream close failed: {}", e.toString());
+                pendingException = e;
+
+                // Retry close - first attempt drained stream but threw exception before cleanup,
+                // retry finds stream already drained and completes cleanup successfully
+                try {
+                    flightStream.close();
+                    // Retry succeeded - clear the exception
+                    pendingException = null;
+                } catch (Exception retryException) {
+                    // Retry also failed - keep original exception
+                    // but continue to close collected Arrow resources anyway
+                    LOG.error("FlightStream close failed even after retry attempt", retryException);
+                }
+            }
+
+            // ALWAYS try to close collected Arrow resources
+            try {
                 AutoCloseables.close(autoCloseable);
             } catch (Exception e) {
-                throw new RuntimeException(e);
+                LOG.error("AutoCloseable close failed", e);
+                if (pendingException != null) {
+                    pendingException.addSuppressed(e);
+                } else {
+                    pendingException = e;
+                }
+            }
+
+            // Throw pending exceptions
+            if (pendingException != null) {
+                throw new RuntimeException(pendingException);
             }
         }
     }

src/test/java/com/influxdb/v3/client/issues/MemoryLeakIssueTest.java

@@ -0,0 +1,174 @@
+/*
+ * The MIT License
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.influxdb.v3.client.issues;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.logging.Logger;
+import java.util.stream.Stream;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
+
+import com.influxdb.v3.client.InfluxDBClient;
+import com.influxdb.v3.client.PointValues;
+import com.influxdb.v3.client.config.ClientConfig;
+
+public class MemoryLeakIssueTest {
+
+    private static final Logger LOG = Logger.getLogger(MemoryLeakIssueTest.class.getName());
+
+    /**
+     * Tests that interrupting a thread during stream consumption does not cause Arrow memory leaks.
+     * <p>
+     * This test creates a query thread that slowly consumes results, then interrupts it mid-processing.
+     * The interrupt causes FlightStream.close() to throw InterruptedException, which previously bypassed
+     * cleanup code and left Apache Arrow buffers unreleased. With the fix, client.close() should complete
+     * successfully without throwing "Memory was leaked" errors.
+     */
+    @EnabledIfEnvironmentVariable(named = "TESTING_INFLUXDB_URL", matches = ".*")
+    @EnabledIfEnvironmentVariable(named = "TESTING_INFLUXDB_TOKEN", matches = ".*")
+    @EnabledIfEnvironmentVariable(named = "TESTING_INFLUXDB_DATABASE", matches = ".*")
+    @Test
+    void testStreamCloseWithThreadInterrupt() throws Exception {
+        String host = System.getenv("TESTING_INFLUXDB_URL");
+        String token = System.getenv("TESTING_INFLUXDB_TOKEN");
+        String database = System.getenv("TESTING_INFLUXDB_DATABASE");
+        String measurement = "memory_leak_test_" + System.currentTimeMillis();
+        String sql = String.format("SELECT * FROM %s", measurement);
+
+        // Prepare config
+        ClientConfig config = new ClientConfig.Builder()
+                .host(host)
+                .token(token.toCharArray())
+                .database(database)
+                .writeNoSync(true)
+                .build();
+
+        try (InfluxDBClient client = InfluxDBClient.getInstance(config)) {
+            // Write test data
+            LOG.info("Writing test data...");
+            for (int i = 0; i < 3; i++) {
+                client.writeRecord(String.format("%s,id=%04d temp=%f",
+                        measurement, i, 20.0 + Math.random() * 10));
+            }
+
+            // Wait for data to be queryable (CI environments can be slower)
+            LOG.info("Waiting for data to be available...");
+            int attempts = 0;
+            boolean hasData = false;
+            while (attempts < 10 && !hasData) {
+                try (Stream<PointValues> testStream = client.queryPoints(sql)) {
+                    hasData = testStream.findFirst().isPresent();
+                }
+                if (!hasData) {
+                    LOG.info("Data not yet available, waiting... (attempt " + (attempts + 1) + "/10)");
+                    TimeUnit.MILLISECONDS.sleep(500);
+                    attempts++;
+                }
+            }
+
+            if (!hasData) {
+                Assertions.fail("No data available after writing and waiting " + (attempts * 500) + "ms");
+            }
+            LOG.info("Data is available, starting test...");
+
+        }
+
+        // Query data
+        InfluxDBClient client = InfluxDBClient.getInstance(config);
+        //noinspection TryFinallyCanBeTryWithResources
+        try {
+            // Synchronization to ensure we interrupt during consumption
+            CountDownLatch consumingStarted = new CountDownLatch(1);
+            AtomicInteger rowsProcessed = new AtomicInteger(0);
+            AtomicInteger exceptionsThrown = new AtomicInteger(0);
+
+            Thread queryThread = new Thread(() -> {
+                try (Stream<PointValues> stream = client.queryPoints(sql)) {
+                    LOG.info("queryPoints returned");
+                    stream.forEach(pv -> {
+                        int count = rowsProcessed.incrementAndGet();
+
+                        // Signal that we've started consuming
+                        if (count == 1) {
+                            LOG.info("Started consuming - ready for interrupt");
+                            consumingStarted.countDown();
+                        }
+
+                        try {
+                            // Slow consumption to ensure we're mid-stream when interrupted
+                            TimeUnit.MILLISECONDS.sleep(100);
+                        } catch (InterruptedException e) {
+                            LOG.info("INTERRUPTED during consume! (after " + count + " rows)");
+                            Thread.currentThread().interrupt();
+                            // Throw exception to stop stream consumption immediately; try-with-resources will then
+                            // close stream in interrupted state
+                            throw new RuntimeException("Interrupted", e);
+                        }
+                    });
+                } catch (Exception e) {
+                    exceptionsThrown.incrementAndGet();
+                    LOG.info("Exception caught: " + e);
+                }
+            });
+
+            queryThread.start();
+
+            // Wait for thread to start consuming
+            if (!consumingStarted.await(10, TimeUnit.SECONDS)) {
+                Assertions.fail("Thread didn't start consuming in time!");
+            }
+
+            // Give it a moment to be mid-processing
+            TimeUnit.MILLISECONDS.sleep(50);
+
+            // Interrupt during processing
+            LOG.info("Interrupting thread...");
+            queryThread.interrupt();
+
+            // Wait for thread to finish
+            queryThread.join(10000);
+
+            // Verify that thread started processing rows
+            if (rowsProcessed.get() == 0) {
+                Assertions.fail("Thread didn't process any rows");
+            }
+
+            // Verify that exception was thrown due to interrupt
+            if (exceptionsThrown.get() == 0) {
+                Assertions.fail("No exception was thrown - interrupt might not have worked");
+            }
+
+        } catch (Exception e) {
+            LOG.severe("Test failed: " + e.getMessage());
+            throw e;
+        } finally {
+            // Now close the client.
+            // It should not throw `Memory was leaked by query. Memory leaked: (...)` error!
+            LOG.info("Closing the client...");
+            client.close();
+        }
+    }
+}