Azure Java "Web app with MySQL in-app" having Communications link failure to database

Question

I am trying to deploy a java spring-mvc web app into azure, but having trouble on connecting the MySQL in-app.

After deployed, I have updated the host, port, username and password in my xml according to the connection string in

/data/mysql/MYSQLCONNSTR_localdb.txt

Any helps on this? A side question, anyone how to get the connection string in java? so that if the port number changed, will not need to update the xml.

Encounter this error:

Type Exception Report

Message Request processing failed; nested exception is org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:982)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
    org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:80)
    org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:394)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:474)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:484)
    jbr.springmvc.dao.UserDaoImpl.validateUser(UserDaoImpl.java:44)
    jbr.springmvc.service.UserServiceImpl.validateUser(UserServiceImpl.java:26)
    jbr.springmvc.controller.LoginController.loginProcess(LoginController.java:28)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    java.lang.reflect.Method.invoke(Method.java:498)
    org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
    sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
    com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
    com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2209)
    com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:776)
    com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
    sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
    com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:352)
    com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:284)
    java.sql.DriverManager.getConnection(DriverManager.java:664)
    java.sql.DriverManager.getConnection(DriverManager.java:208)
    org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:153)
    org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriver(DriverManagerDataSource.java:144)
    org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnectionFromDriver(AbstractDriverBasedDataSource.java:196)
    org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnection(AbstractDriverBasedDataSource.java:159)
    org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111)
    org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77)
    org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:394)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:474)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:484)
    jbr.springmvc.dao.UserDaoImpl.validateUser(UserDaoImpl.java:44)
    jbr.springmvc.service.UserServiceImpl.validateUser(UserServiceImpl.java:26)
    jbr.springmvc.controller.LoginController.loginProcess(LoginController.java:28)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    java.lang.reflect.Method.invoke(Method.java:498)
    org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
    sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
    com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
    com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:343)
    com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2132)
    com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:776)
    com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
    sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
    com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:352)
    com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:284)
    java.sql.DriverManager.getConnection(DriverManager.java:664)
    java.sql.DriverManager.getConnection(DriverManager.java:208)
    org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:153)
    org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriver(DriverManagerDataSource.java:144)
    org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnectionFromDriver(AbstractDriverBasedDataSource.java:196)
    org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnection(AbstractDriverBasedDataSource.java:159)
    org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111)
    org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77)
    org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:394)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:474)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:484)
    jbr.springmvc.dao.UserDaoImpl.validateUser(UserDaoImpl.java:44)
    jbr.springmvc.service.UserServiceImpl.validateUser(UserServiceImpl.java:26)
    jbr.springmvc.controller.LoginController.loginProcess(LoginController.java:28)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    java.lang.reflect.Method.invoke(Method.java:498)
    org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

java.net.SocketException: Permission denied: connect
    java.net.TwoStacksPlainSocketImpl.socketConnect(Native Method)
    java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
    java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
    java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
    java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
    java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    java.net.Socket.connect(Socket.java:589)
    java.net.Socket.connect(Socket.java:538)
    java.net.Socket.<init>(Socket.java:434)
    java.net.Socket.<init>(Socket.java:244)
    com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:253)
    com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:292)
    com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2132)
    com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:776)
    com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
    sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
    com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:352)
    com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:284)
    java.sql.DriverManager.getConnection(DriverManager.java:664)
    java.sql.DriverManager.getConnection(DriverManager.java:208)
    org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:153)
    org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriver(DriverManagerDataSource.java:144)
    org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnectionFromDriver(AbstractDriverBasedDataSource.java:196)
    org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnection(AbstractDriverBasedDataSource.java:159)
    org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111)
    org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77)
    org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:394)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:474)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:484)
    jbr.springmvc.dao.UserDaoImpl.validateUser(UserDaoImpl.java:44)
    jbr.springmvc.service.UserServiceImpl.validateUser(UserServiceImpl.java:26)
    jbr.springmvc.controller.LoginController.loginProcess(LoginController.java:28)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    java.lang.reflect.Method.invoke(Method.java:498)
    org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Note The full stack trace of the root cause is available in the server logs.

The web app is working fine in my local, able to connect and insert data into database.

Appreciate the helps.

score 3 · Accepted Answer · answered Jan 03 '18 at 08:43

3

I faced similar issue. Finally found out that, I must use latest version of MySQL-connector-java jar. I was using 5.1.6 version before.. the error was gone after upgrading to 5.1.30 version or later

answered Jan 03 '18 at 08:43

Venky

474
1
6
17

Many thanks Venky, after upgraded to 5.1.30 version connector it work. – ken lee Jan 10 '18 at 06:00

Jay Gong · Answer 2 · 2017-09-13T09:21:23.643

Depending on your description of your issue, it seems that you've written the MySql in-app configuration information as a constant in your xml file.

However,it's important to know that the port in the configuration parameters changes randomly as the application restarts. So you need to configure connectString dynamically.

You could find the configuration information for connection in the MYSQLCONNSTR_localdb.txt you mentioned.Actually,MYSQLCONNSTR_localdb is an environment variable that you could fetch it in the Java via the getEnv method.

You could refer to the code below to re-configure your MYSQL connection parameters dynamically.

    String connectString = System.getenv("MYSQLCONNSTR_localdb");

    response.getWriter().append("connectString: " + connectString);

    String database = "";
    String port = "";
    String username = "";
    String password = "";

    String[] strArray = connectString.split(";");
    for (int i = 0; i < strArray.length; i++) {
        String[] paramArray = strArray[i].split("=");
        switch (i) {
        case 0:
            database = paramArray[1];
            continue;
        case 1:
            port = paramArray[1];
            continue;
        case 2:
            username = paramArray[1];
            continue;
        case 3:
            password = paramArray[1];
            continue;
        }
    }

    String url = "jdbc:mysql://" + port + "/" + database + "?"
            + "user=" + username + "&password=" + password + "&useUnicode=true&characterEncoding=UTF8";

    response.getWriter().append("url:" + url);

    try {
        Class.forName("com.mysql.jdbc.Driver");

        Connection conn = DriverManager.getConnection(url);

        response.getWriter().append("     connect success");

        Statement stmt = conn.createStatement();

        String sql = "create table student(NO char(20),name varchar(20),primary key(NO))";

        int result = stmt.executeUpdate(sql);

        response.getWriter().append("     insert result" + result);

    } catch (Exception e) {
        e.printStackTrace();
    }

Hope it helps you.

Update Answer

Please check whether <environmentVariable name="JAVA_OPTS" value="-Djava.net.preferIPv4Stack=true" /> is configured in your web.config file on Kudu.

The container needs to be configured for IPv4 traffic only which mentioned here.

You could refer to the solutions from this thread Solving a "communications link failure" with JDBC and MySQL and get more details about MySql in-app from here.

Hi Jay, appreciate your reply, will try it now. Btw, I getting the port number from the MyPHPadmin portal. — ken lee, Sep 13 '17 at 06:34
I still hitting the same error in the application after update to use the connection string. Any ideas? To reproduce it, you can go to http://springmvcuser.azurewebsites.net/SpringMvcUser/ and click on the Login and click on the OK button, it will shows the errors. — ken lee, Sep 13 '17 at 08:59
Thank you for the updates, But I still encounter the same error, I have followed the instruction in this link https://learn.microsoft.com/en-us/azure/app-service-web/web-sites-java-custom-upload In my server.xml all have been set to: Shutdown port = -1 HTTP connector port = ${port.http} HTTP connector address = "127.0.0.1" Comment out HTTPS and AJP connectors catalina.properties file already has java.net.preferIPv4Stack=true I will try check other solution from https://stackoverflow.com/questions/6865538/solving-a-communications-link-failure-with-jdbc-and-mysql — ken lee, Sep 13 '17 at 11:21
@kenlee Please refer to steps from this document https://learn.microsoft.com/en-us/azure/app-service-web/web-sites-java-custom-upload and configure web.config file(if it doesn't exist please create it) and re-try. — Jay Gong, Sep 14 '17 at 02:12
sorry for late reply, @jaygong have try with creating we.config file and put it in \wwwroot folder, still getting the same error. — ken lee, Sep 14 '17 at 08:40
@kenlee Never mind,I did want to help you to solve this issue. Would you please post your web.config file content? — Jay Gong, Sep 14 '17 at 08:49
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/154425/discussion-between-ken-lee-and-jay-gong). — ken lee, Sep 14 '17 at 09:26

Azure Java "Web app with MySQL in-app" having Communications link failure to database

2 Answers2