fix to release the invalid session for SessionPool

client/src/main/java/com/vesoft/nebula/client/graph/NebulaSession.java

@@ -15,11 +15,15 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicReference;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class NebulaSession implements Serializable {
 
     private static final long serialVersionUID = -88438249377120255L;
 
+    private final Logger log = LoggerFactory.getLogger(this.getClass());
+
     private long sessionID;
     private int timezoneOffset;
     private SyncConnection connection;
@@ -65,8 +69,12 @@ public ResultSet executeWithParameter(String stmt, Map<String, Object> parameter
     }
 
     public void release() {
-        connection.signout(sessionID);
-        connection.close();
+        try {
+            connection.signout(sessionID);
+            connection.close();
+        } catch (Exception e) {
+            log.warn("release session failed, " + e.getMessage());
+        }
         connection = null;
     }
 }

client/src/main/java/com/vesoft/nebula/client/graph/SessionPoolConfig.java

@@ -32,7 +32,7 @@ public class SessionPoolConfig implements Serializable {
     // must be less than NebulaGraph's session_idle_timeout_secs, unit: second
     private int cleanTime = 3600;
 
-    // The healthCheckTime for schedule check the health of session
+    // The healthCheckTime for schedule check the health of session, unit: second
     private int healthCheckTime = 600;
 
     // The wait time to get idle connection, unit ms

client/src/test/java/com/vesoft/nebula/client/graph/net/TestSessionPool.java

@@ -14,12 +14,14 @@
 import com.vesoft.nebula.client.graph.exception.BindSpaceFailedException;
 import com.vesoft.nebula.client.graph.exception.ClientServerIncompatibleException;
 import com.vesoft.nebula.client.graph.exception.IOErrorException;
+import com.vesoft.nebula.client.util.ProcessUtil;
 import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
+import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -259,4 +261,67 @@ public void testThreadSafe() {
         assert failedCount.get() == 0;
     }
 
+    @Test
+    public void testReleaseBrokenSession() {
+        List<HostAddress> addresses = Arrays.asList(new HostAddress(ip, 9669),
+                new HostAddress(ip, 9670), new HostAddress(ip, 9671));
+        SessionPoolConfig config = new SessionPoolConfig(addresses, "space_for_session_pool",
+                "root", "nebula");
+        config.setHealthCheckTime(5);
+        SessionPool sessionPool = new SessionPool(config);
+        assert sessionPool.init();
+
+        Runtime runtime = Runtime.getRuntime();
+        try {
+            for (int i = 0; i < 10; i++) {
+                try {
+                    ResultSet resultSet = sessionPool.execute("SHOW SPACES;");
+                    if (!resultSet.isSucceeded()) {
+                        System.out.println("show spaces failed, ErrorCode:"
+                                + resultSet.getErrorCode() + " ErrorMessage："
+                                + resultSet.getErrorMessage());
+                    }
+                } catch (Exception e) {
+                    e.printStackTrace();
+                    assert false;
+                }
+            }
+
+            String cmd = "docker stop nebula-docker-compose_graphd0_1";
+            Process p = runtime.exec(cmd);
+            p.waitFor(5, TimeUnit.SECONDS);
+            ProcessUtil.printProcessStatus(cmd, p);
+
+            // sleep 6 seconds to process the healthy check schedule task
+            Thread.sleep(6000);
+
+            for (int i = 0; i < 10; i++) {
+                try {
+                    ResultSet resultSet = sessionPool.execute("SHOW SPACES;");
+                    if (!resultSet.isSucceeded()) {
+                        System.out.println("show spaces failed, ErrorCode:"
+                                + resultSet.getErrorCode() + " ErrorMessage："
+                                + resultSet.getErrorMessage());
+                    }
+                } catch (Exception e) {
+                    e.printStackTrace();
+                    assert false;
+                }
+            }
+
+            sessionPool.close();
+        } catch (Exception e) {
+            e.printStackTrace();
+            Assert.assertFalse(e.getMessage(), false);
+        } finally {
+            try {
+                runtime.exec("docker start nebula-docker-compose_graphd0_1")
+                        .waitFor(5, TimeUnit.SECONDS);
+                TimeUnit.SECONDS.sleep(5);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
 }