I have a data source configured with its connections pool ready to use, and it is exposed to my application via JDNI, but the code my colleagues wrote actually opens and closes a connection for every query. How does WSO2 handle this? Does it really close the connection given by the pool, or it ignores the close and just considers this connection free to be added back to the pool and ready to be used by any other client?
Connection conn = null;
CallableStatement cStmt = null;
try {
Hashtable<String, String> environment = new Hashtable<String, String>();
environment.put("java.naming.factory.initial", "org.wso2.carbon.tomcat.jndi.CarbonJavaURLContextFactory");
Context initContext = new InitialContext(environment);
DataSource ds = (DataSource) initContext.lookup("jdbc/tvaccount");
if (ds != null) {
conn = ds.getConnection();
cStmt = conn.prepareCall("{call getAccountStatusAttr(?)}");
cStmt.setString("pUserLogin", userName);
cStmt.execute();
}
} catch (Exception e) {
log.error("Exception while getting account status: ", e);
} finally {
if (cStmt != null) {
try {
cStmt.close();
} catch (SQLException e) {
}
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
}
}
}
Have you added this java code as a JAR file in WSO2 ESB and then accessed the method by using class mediator? if this is the case then it behaves like a normal java code wherein once the query is executed the connection will be closed.
Related
I have a GRPC server written on C#.
internal class Program
{
internal static void Main(string[] args)
{
using (var waitHandle = new AutoResetEvent(false))
{
void OnConsoleOnCancelKeyPress(object o, ConsoleCancelEventArgs e)
{
e.Cancel = true;
// ReSharper disable once AccessToDisposedClosure
waitHandle.Set();
}
Console.CancelKeyPress += OnConsoleOnCancelKeyPress;
var config = new AppConfig(new ConfigurationBuilder()
.AddJsonFile("appsettings.json", false)
.Build());
var containerBuilder = new ContainerBuilder();
containerBuilder.RegisterModule(new Module());
containerBuilder.RegisterModule(new Data.Module(config.Region, config.TablePrefix));
using (var container = containerBuilder.Build())
{
var buyRatesService = container.Resolve<BuyRatesService>();
var logger = container.Resolve<ILogger<Program>>();
var server = new Server
{
Services =
{
BuyRates.BindService(buyRatesService)
},
Ports = {new ServerPort("0.0.0.0", 50051, ServerCredentials.Insecure)}
};
try
{
server.Start();
logger.LogDebug("Service started");
waitHandle.WaitOne();
}
catch (Exception e)
{
logger.LogCritical("Application terminated unexpectedly. Exception {#exception}", e);
}
finally
{
server.ShutdownAsync().Wait();
Console.CancelKeyPress -= OnConsoleOnCancelKeyPress;
}
}
}
}
}
It works fine locally. I deploy it to ecs instance(Docker). The container port is 50051. ALB and Route 53 are used.
When I'm trying to connect to someroute54uri.net:50051 I get an error
Grpc.Core.RpcException: Status(StatusCode=Unavailable, Detail="Connect Failed").
In case when I'm trying to connect to someroute54uri.net, I get an error
Grpc.Core.RpcException: Status(StatusCode=Unavailable, Detail="Trying to connect an http1.x server").
Thanks!.
Please, let me know if additional information helps to solve the issue.
I recently upgraded from jetty 9.3.11 to 9.4.6 . Since 9.4.x does not support HashSessionManager, I created my own custom SessionHandler. But when i attach this SessionHandler to the WebAppContext then the context becomes null when trying to access from servlets. there are no errors thrown in the logs.
Relevant section of code:
MyCustomSessionHandler sessionHandler = new MyCustomSessionHandler();
HandlerCollection handlers_ = new HandlerCollection(true);
COntextHandlerCollection chc_ = new ContextHandlerCollection();
for(WebAppConfig wap: webAppConfigs) //webappconfig a POJO from where I am getting webapp configs
{
String path = wap.getPath();
String warFile = wap.getWarFile();
WebAppContext context =
new WebAppContext(chc_, warFile, path);
// context.setSessionHandler(new SessionHandler()); // this one works.
context.setSessionHandler(sessionHandler); // this one doesnt work.
for (ServletConfig servletConfig: wap.getServletConfigs()) //ServletConfig is another POJO to get servlet configs
{
String servletName = servletConfig.getName();
String servletPath = servletConfig.getPath();
Servlet servlet = servletConfig.getServlet();
ServletHolder servletHolder = new ServletHolder(servlet);
context.addServlet(servletHolder, servletPath);
}
}
handlers_.setHandlers(new Handler[] { chc_, new DefaultHandler()});
server_.setHandler(handlers_);
Sample of my custom Session handler
public class MyCUstomSessionHandler extends SessionHandler
{
public MyCustomSessionHandler()
{
super();
}
public void setSecureCookies(boolean secureCookies)
{
getSessionCookieConfig().setSecure(secureCookies);
}
public void setHttpOnly(boolean httpOnly)
{
getSessionCookieConfig().setHttpOnly(httpOnly);
}
public void setMaxCookieAge(int age)
{
getSessionCookieConfig().setMaxAge(age);
}
}
Further clarification: It happens because I create a singleton sessionhandler and share it across different WepAppContext as a way of sharing sessions among them. This method seemed work fine without issues in 9.3 but doesn't work with new session management in 9.4.
Any help to solve this problem is appreciated.
I solved it by
setting cookie path to root ("/")
extending the getSession() function of SessionHandler to loop through all the contexts to check if session is created for the cookie in any other context.
/* check all contexts for sessions*/
public Session getSession(String id)
{
Session session = getLocalSession(id);
if (session == null)
{
for (SessionHandler manager: getSessionIdManager().getSessionHandlers())
{
if (manager.equals(this) ||
!(manager instanceof CustomSessionHandler))
{
continue;
}
session = ((CustomSessionHandler)manager).getLocalSession(id);
if (session != null)
{
break;
}
}
// should we duplicate sessions in each context?
// will we end up with inconsistent sessions?
/*
if (externalSession != null)
{
try
{
getSessionCache().put(id, externalSession);
}
catch (Exception e)
{
LOG.warn("Unable to save session to local cache.");
}
}
*/
}
return session;
}
/* ------------------------------------------------------------ */
/**
* Get a known existing session
* #param id The session ID stripped of any worker name.
* #return A Session or null if none exists.
*/
public Session getLocalSession(String id)
{
return super.getSession(id);
}
I am using Presto to query Hive tables in EMR. I initialized presto driver and get the connection, but when I am trying to execute a query on that connection, I am getting an error: Server refused connection: http://aws.address/v1/statement.
Do I need to set Hive/AWS credentials before using it? How can I do it?
public void init() {
try {
Class.forName("com.facebook.presto.jdbc.PrestoDriver");
if(connection == null)
connection = DriverManager.getConnection(url,username,password);
// url = "jdbc:presto://aws.address:8889/hive/default"
} catch (ClassNotFoundException | SQLException e) {
// TOD: handle exception
e.printStackTrace();
}
}
public void executeMyQuery() {
if(connection == null) {
connection = driver.getConnection();
}
ResultSet resultSet = null;
Statement stmt = connection.createStatement();
try {
resultSet = stmt.executeQuery(query);
} catch (Exception e) {
logger.error("Failed to execute query, with error: ",e);
} finally {
if(resultSet != null) {
try {
resultSet.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(stmt != null){
stmt.close();
}
}
}
I needed to use 'port forwarding' command (ssh) in order to reach presto driver in AWS.
I am using Jersey REST Webservices for my Application which is like a type of blog website ( means no user registration or authentication are required)
I have some webservices which queries the database and sends the data to the Front End .
As you know the user can see the webservice calls in browser network tab and fire the query manually
My question is , how can i protect sever / Service from being hit continously (for loop written manually to break the application)
This is how my service looks like
#GET
#Produces("text/plain")
public String displaylatestnews() {
String latestnews = "";
PreparedStatement selectpstmt = null;
ResultSet selectRset = null;
Connection conn = null;
String selectsql = "SELECT rssjson from rssfeeds limit 1";
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection(DB_URL, USER, PASS);
selectpstmt = conn.prepareStatement(selectsql);
selectRset = selectpstmt.executeQuery();
if (selectRset.next()) {
latestnews = selectRset.getString("rssjson");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
selectRset.close();
} catch (SQLException e) {
e.printStackTrace();
}
try {
selectpstmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
return "jsonCallback(" + latestnews.toString() + ")";
}
You can start avoiding creating a connection to mysql every time there's a request, secondly you can add some sort of caching to start with. Even a cache that only lasts few seconds can save tons of db accesses.
I am trying to implementing HttpSessionListener interface with embedded jetty with proxy servlet, I have registered SessionListener, but it is not getting invoked at all, here is the code,
public class JettyProxy {
public static void main(String[] args) throws Exception {
Server server = new Server();
CustomProxyServlet customProxyServlet = new CustomProxyServlet();
ServerConnector connector = new ServerConnector(server);
connector.setPort(8888);
server.addConnector(connector);
ConnectHandler proxy = new ConnectHandler();
server.setHandler(proxy);
ServletContextHandler context = new ServletContextHandler(proxy, "/",
ServletContextHandler.SESSIONS);
ServletHolder proxyServlet = new ServletHolder(customProxyServlet);
context.addServlet(proxyServlet, "/*");
if (context.getSessionHandler() == null) {
System.out.println("Session handler is null");
} else {
System.out.println("Session handler is not null");
}
if (context.getSessionHandler().getSessionManager() == null) {
System.out.println("Managaer it null");
} else {
System.out.println("Manager is not null");
}
context.getSessionHandler().addEventListener(new CustomSessionHandler());
server.start();
server.join();
}
}
SessionHandler is not null, session creating events are not getting triggered, please help me, what is the procedure get session events?
you should have a SessionManager. i usually use :
org.eclipse.jetty.server.session.HashSessionManager.HashSessionManager()
and
org.eclipse.jetty.server.session.SessionHandler.SessionHandler(SessionManager manager)
then you should set the handler for the context
context.setHandler(sessionHandler);
sessionHandler.addEventListener("Your Session Listener");