[BugFix] Fix show property for non-existed user error result (backport …

…#41351) (#41482)

Co-authored-by: yiming <[email protected]>

fe/fe-core/src/main/java/com/starrocks/authentication/AuthenticationMgr.java

@@ -35,6 +35,7 @@
 import com.starrocks.privilege.UserPrivilegeCollectionV2;
 import com.starrocks.qe.ConnectContext;
 import com.starrocks.server.GlobalStateMgr;
+import com.starrocks.sql.analyzer.SemanticException;
 import com.starrocks.sql.ast.CreateUserStmt;
 import com.starrocks.sql.ast.DropUserStmt;
 import com.starrocks.sql.ast.UserIdentity;
@@ -173,11 +174,31 @@ public boolean doesUserExist(UserIdentity userIdentity) {
         }
     }
 
+    /**
+     * Get max connection number of the user, if the user is ephemeral, i.e. the user is saved in SR,
+     * but some external system, like LDAP, return default max connection number
+     * @param currUserIdentity user identity of current connection
+     * @return max connection number of the user
+     */
+    public long getMaxConn(UserIdentity currUserIdentity) {
+        if (currUserIdentity.isEphemeral()) {
+            return DEFAULT_MAX_CONNECTION_FOR_EXTERNAL_USER;
+        } else {
+            String userName = currUserIdentity.getUser();
+            return getMaxConn(userName);
+        }
+    }
+
+    /**
+     * Get max connection number based on plain username, the user should be an internal user,
+     * if the user doesn't exist in SR, it will throw an exception.
+     * @param userName plain username saved in SR
+     * @return max connection number of the user
+     */
     public long getMaxConn(String userName) {
         UserProperty userProperty = userNameToProperty.get(userName);
         if (userProperty == null) {
-            // TODO(yiming): find a better way to specify max connections for external user, like ldap, kerberos etc.
-            return DEFAULT_MAX_CONNECTION_FOR_EXTERNAL_USER;
+            throw new SemanticException("Unknown user: " + userName);
         } else {
             return userNameToProperty.get(userName).getMaxConn();
         }

fe/fe-core/src/main/java/com/starrocks/qe/ConnectScheduler.java

@@ -134,9 +134,9 @@ public boolean registerConnection(ConnectContext ctx) {
         if (connCountByUser.get(ctx.getQualifiedUser()) == null) {
             connCountByUser.put(ctx.getQualifiedUser(), new AtomicInteger(0));
         }
-        int currentConns = connCountByUser.get(ctx.getQualifiedUser()).get();
-        long currentMaxConns = ctx.getGlobalStateMgr().getAuthenticationMgr().getMaxConn(ctx.getQualifiedUser());
-        if (currentConns >= currentMaxConns) {
+        int currentConn = connCountByUser.get(ctx.getQualifiedUser()).get();
+        long currentMaxConn = ctx.getGlobalStateMgr().getAuthenticationMgr().getMaxConn(ctx.getCurrentUserIdentity());
+        if (currentConn >= currentMaxConn) {
             return false;
         }
         numberConnection.incrementAndGet();

fe/fe-core/src/test/java/com/starrocks/authentication/AuthenticationManagerTest.java

@@ -24,6 +24,7 @@
 import com.starrocks.qe.ConnectContext;
 import com.starrocks.qe.DDLStmtExecutor;
 import com.starrocks.qe.SetDefaultRoleExecutor;
+import com.starrocks.sql.analyzer.SemanticException;
 import com.starrocks.sql.ast.AlterUserStmt;
 import com.starrocks.sql.ast.CreateRoleStmt;
 import com.starrocks.sql.ast.CreateUserStmt;
@@ -299,8 +300,7 @@ public void testDropAlterUser() throws Exception {
         Assert.assertFalse(manager.doesUserExist(testUserWithIp));
 
         // can't get max connection after all test user are dropped
-        Assert.assertEquals(AuthenticationMgr.DEFAULT_MAX_CONNECTION_FOR_EXTERNAL_USER,
-                manager.getMaxConn("test"));
+        Assert.assertThrows(SemanticException.class, () -> manager.getMaxConn("test"));
     }
 
     @Test

fe/fe-core/src/test/java/com/starrocks/sql/analyzer/PrivilegeCheckerTest.java

@@ -1123,10 +1123,12 @@ public void testShowProcessList(@Mocked MysqlChannel channel,
 
         ConnectContext ctx1 = new ConnectContext(socketChannel);
         ctx1.setQualifiedUser("test");
+        ctx1.setCurrentUserIdentity(new UserIdentity("test", "%"));
         ctx1.setGlobalStateMgr(GlobalStateMgr.getCurrentState());
         ctx1.setConnectionId(1);
         ConnectContext ctx2 = new ConnectContext(socketChannel);
         ctx2.setQualifiedUser("test2");
+        ctx2.setCurrentUserIdentity(new UserIdentity("test2", "%"));
         ctx2.setGlobalStateMgr(GlobalStateMgr.getCurrentState());
         ctx2.setConnectionId(2);