IGNITE-26959: Fix thin client continuous query cleanup on disconnect

modules/core/src/main/java/org/apache/ignite/internal/processors/platform/client/ClientConnectionContext.java

@@ -99,7 +99,7 @@ public class ClientConnectionContext extends ClientListenerAbstractConnectionCon
     private ClientRequestHandler handler;
 
     /** Handle registry. */
-    private final ClientResourceRegistry resReg = new ClientResourceRegistry();
+    private final ClientResourceRegistry resReg;
 
     /** Max cursors. */
     private final int maxCursors;
@@ -151,6 +151,7 @@ public ClientConnectionContext(
         this.maxCursors = maxCursors;
         maxActiveTxCnt = thinCfg.getMaxActiveTxPerConnection();
         maxActiveComputeTasks = thinCfg.getMaxActiveComputeTasksPerConnection();
+        resReg = new ClientResourceRegistry(ctx.log(ClientResourceRegistry.class));
     }
 
     /**
@@ -267,7 +268,7 @@ public void incrementCursors() {
     }
 
     /**
-     * Increments the cursor count.
+     * Decrement the cursor count.
      */
     public void decrementCursors() {
         curCnt.decrementAndGet();

modules/core/src/main/java/org/apache/ignite/internal/processors/platform/client/ClientResourceRegistry.java

@@ -20,6 +20,7 @@
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicLong;
+import org.apache.ignite.IgniteLogger;
 
 /**
  * Per-connection resource registry.
@@ -31,6 +32,17 @@ public class ClientResourceRegistry {
     /** ID generator. */
     private final AtomicLong idGen = new AtomicLong();
 
+    /** Logger. */
+    private final IgniteLogger log;
+
+    /**
+     * Logger for cleanup errors logging.
+     * @param log Logger.
+     */
+    public ClientResourceRegistry(IgniteLogger log) {
+        this.log = log;
+    }
+
     /**
      * Allocates server handle for an object.
      *
@@ -85,8 +97,23 @@ public void release(long hnd) {
      * Cleans all handles and closes all ClientCloseableResources.
      */
     public void clean() {
-        for (Map.Entry e : res.entrySet())
-            closeIfNeeded(e.getValue());
+        for (Map.Entry<Long, Object> e : res.entrySet()) {
+            Long id = e.getKey();
+            Object obj = e.getValue();
+
+            // Delete from registry before close, to avoid keeping references after clean.
+            res.remove(id, obj);
+
+            try {
+                closeIfNeeded(obj);
+            }
+            catch (Exception ex) {
+                if (log != null && log.isDebugEnabled())
+                    log.debug("Failed to close client resource on disconnect [id=" + id +
+                        ", res=" + obj +
+                        ", err=" + ex.getClass().getSimpleName() + ": " + ex.getMessage() + ']');
+            }
+        }
     }
 
     /**

modules/core/src/main/java/org/apache/ignite/internal/processors/platform/client/cache/ClientCacheQueryContinuousHandle.java

@@ -86,9 +86,12 @@ public void startNotifications(long id) {
     @Override public void close() {
         if (closeGuard.compareAndSet(false, true)) {
             assert cur != null;
-            cur.close();
-
-            ctx.decrementCursors();
+            try {
+                cur.close();
+            }
+            finally {
+                ctx.decrementCursors();
+            }
         }
     }
 }