[ 
https://issues.apache.org/jira/browse/DRILL-5098?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15736360#comment-15736360
 ] 

ASF GitHub Bot commented on DRILL-5098:
---------------------------------------

Github user sudheeshkatkam commented on a diff in the pull request:

    https://github.com/apache/drill/pull/679#discussion_r91796042
  
    --- Diff: 
exec/jdbc/src/test/java/org/apache/drill/jdbc/test/JdbcConnectTriesTestEmbeddedBits.java
 ---
    @@ -0,0 +1,162 @@
    +/**
    + * Licensed to the Apache Software Foundation (ASF) under one
    + * or more contributor license agreements.  See the NOTICE file
    + * distributed with this work for additional information
    + * regarding copyright ownership.  The ASF licenses this file
    + * to you under the Apache License, Version 2.0 (the
    + * "License"); you may not use this file except in compliance
    + * with the License.  You may obtain a copy of the License at
    + * <p>
    + * http://www.apache.org/licenses/LICENSE-2.0
    + * <p>
    + * Unless required by applicable law or agreed to in writing, software
    + * distributed under the License is distributed on an "AS IS" BASIS,
    + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    + * See the License for the specific language governing permissions and
    + * limitations under the License.
    + */
    +
    +package org.apache.drill.jdbc.test;
    +
    +import org.apache.drill.exec.rpc.InvalidConnectionInfoException;
    +import org.apache.drill.exec.rpc.RpcException;
    +import org.apache.drill.jdbc.Driver;
    +import org.apache.drill.jdbc.JdbcTestBase;
    +
    +import org.junit.Test;
    +
    +import java.sql.SQLException;
    +import java.sql.Connection;
    +
    +import java.util.concurrent.ExecutionException;
    +
    +import static junit.framework.Assert.assertNotNull;
    +import static junit.framework.TestCase.fail;
    +import static org.junit.Assert.assertNull;
    +import static org.junit.Assert.assertTrue;
    +
    +public class JdbcConnectTriesTestEmbeddedBits extends JdbcTestBase {
    +
    +  @Test
    +  public void testDirectConnectionConnectTriesEqualsDrillbitCount() throws 
SQLException {
    +    Connection connection = null;
    +    try {
    +      connection = new 
Driver().connect("jdbc:drill:drillbit=127.0.0.1:5000,127.0.0.1:5001;" + 
"tries=2",
    --- End diff --
    
    Create one driver and use across tests.


> Improving fault tolerance for connection between client and foreman node.
> -------------------------------------------------------------------------
>
>                 Key: DRILL-5098
>                 URL: https://issues.apache.org/jira/browse/DRILL-5098
>             Project: Apache Drill
>          Issue Type: Improvement
>          Components: Client - JDBC
>            Reporter: Sorabh Hamirwasia
>            Assignee: Sorabh Hamirwasia
>              Labels: doc-impacting, ready-to-commit
>             Fix For: 1.10
>
>
> With DRILL-5015 we allowed support for specifying multiple Drillbits in 
> connection string and randomly choosing one out of it. Over time some of the 
> Drillbits specified in the connection string may die and the client can fail 
> to connect to Foreman node if random selection happens to be of dead Drillbit.
> Even if ZooKeeper is used for selecting a random Drillbit from the registered 
> one there is a small window when client selects one Drillbit and then that 
> Drillbit went down. The client will fail to connect to this Drillbit and 
> error out. 
> Instead if we try multiple Drillbits (configurable tries count through 
> connection string) then the probability of hitting this error window will 
> reduce in both the cases improving fault tolerance. During further 
> investigation it was also found that if there is Authentication failure then 
> we throw that error as generic RpcException. We need to improve that as well 
> to capture this case explicitly since in case of Auth failure we don't want 
> to try multiple Drillbits.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to