I want to do the exception handling in Jmeter.Webdriver Webdriver Sampler
Please let me , How to use try/catch block in Jmeter.Webdriver webdriver Sampler ?
You can do this via normal JavaScript try block, here is an example of taking a screenshot when error occurs:
var pkg = JavaImporter(org.openqa.selenium)
var support_ui = JavaImporter(org.openqa.selenium.support.ui.WebDriverWait)
var conditions = org.openqa.selenium.support.ui.ExpectedConditions
var wait = new support_ui.WebDriverWait(WDS.browser, 5)
var exception = null
WDS.sampleResult.sampleStart()
try {
WDS.browser.get('http://example.com')
wait.until(conditions.presenceOfElementLocated(pkg.By.linkText('Not existing link')))
} catch (err) {
WDS.log.error(err.message)
var screenshot = WDS.browser.getScreenshotAs(pkg.OutputType.FILE)
screenshot.renameTo(java.io.File('screenshot.png'))
exception = err
} finally {
throw (exception)
}
WDS.sampleResult.sampleEnd())
Don't forget to "throw" the error after you handle it otherwise it will be "swallowed" and you get a false positive result.
See The WebDriver Sampler: Your Top 10 Questions Answered article for more tips and tricks
Surround the code with try block and add catch block at the end by giving variable name to capture the exception. (in the example, it is exc)
try as follows:
try{
WDS.sampleResult.sampleStart()
WDS.browser.get('http://jmeter-plugins.org')
var pkg = JavaImporter(org.openqa.selenium)
WDS.browser.findElement(pkg.By.id('what')) // there is no such element with id what
WDS.sampleResult.sampleEnd()
}
catch(exc){ //exc variable name
WDS.log.error("element not found" + exc)
}
in the JMeter log, you can see the complete trace of NoSuchElementException, which is raised when trying to find the element by id with the values as what, which is not present in the HTML.
Note: use View Results in Table to see the Sampler response time.
Reference:
https://jmeter-plugins.org/wiki/WebDriverSampler/
Reference Image:
It is same as how do you do in other IDEs like eclipse.
you can see below code
//try block starts here
try{
wait.until(ExpectedConditions.visibilityOfElementLocated(By.xpath("element"))).click();
}
catch(Exception e)
{
WDS.log.info("Exception is : " +e);//you can print the exception in jmeter log.
}
double quotes should be replaced with the single quote if you are using javascript Since the BeanShell is easy and it is similar to java use BeanShell as much as possible
How do I get to the content of Refit.ApiException?
Depending on what the inner content is, I want to let the user know how to proceed. So I see that thrown exception has the following content ...
Content "{\"error\":\"invalid_grant\",\"error_description\":\"The user name or password is incorrect.\"}"
The question is, how do I access that?
You can add one catch block for ApiException. and you can get content from this catch block.
See below:
catch (ApiException ex)
{
var content = ex.GetContentAs<Dictionary<String, String>>();
Debug.WriteLine(ex.Message);
}
Going through the RestService class https://github.com/paulcbetts/refit/blob/master/Refit/RestService.cs
figured out I could use the GetContentAs method
So just did this..
((Refit.ApiException)ex).GetContentAs<Dictionary<String, String>>())
to parse out the key value content.
As an extra heads-up:
GetContentAs<T>(); is now deprecated.
Use GetContentAsAsync<T>(); instead.
With the latest version of API Exception, you can use the following code for getting the API content:
public static void HandleException( Exception exception )
{
var content = ((Refit.ApiException)exception).GetContentAsAsync<Dictionary<string, string>>();
var message = content.Result.FirstOrDefault( pair => pair.Key == "message" ).Value;
Debug.WriteLine(message);
}
I'm having a problem closing my database before an attempt to delete the file. The code is just
myconnection.Close();
File.Delete(filename);
And the Delete throws an exception that the file is still in use. I've re-tried the Delete() in the debugger after a few minutes, so it's not a timing issue.
I have transaction code but it doesn't run at all before the Close() call. So I'm fairly sure it's not an open transaction. The sql commands between open and close are just selects.
ProcMon shows my program and my antivirus looking at the database file. It does not show my program releasing the db file after the close().
Visual Studio 2010, C#, System.Data.SQLite version 1.0.77.0, Win7
I saw a two year old bug just like this but the changelog says it's fixed.
Is there anything else I can check? Is there a way to get a list of any open commands or transactions?
New, working code:
db.Close();
GC.Collect(); // yes, really release the db
bool worked = false;
int tries = 1;
while ((tries < 4) && (!worked))
{
try
{
Thread.Sleep(tries * 100);
File.Delete(filename);
worked = true;
}
catch (IOException e) // delete only throws this on locking
{
tries++;
}
}
if (!worked)
throw new IOException("Unable to close file" + filename);
Encountered the same problem a while ago while writing a DB abstraction layer for C# and I never actually got around to finding out what the issue was. I just ended up throwing an exception when you attempted to delete a SQLite DB using my library.
Anyway, this afternoon I was looking through it all again and figured I would try and find out why it was doing that once and for all, so here is what I've found so far.
What happens when you call SQLiteConnection.Close() is that (along with a number of checks and other things) the SQLiteConnectionHandle that points to the SQLite database instance is disposed. This is done through a call to SQLiteConnectionHandle.Dispose(), however this doesn't actually release the pointer until the CLR's Garbage Collector performs some garbage collection. Since SQLiteConnectionHandle overrides the CriticalHandle.ReleaseHandle() function to call sqlite3_close_interop() (through another function) this does not close the database.
From my point of view this is a very bad way to do things since the programmer is not actually certain when the database gets closed, but that is the way it has been done so I guess we have to live with it for now, or commit a few changes to System.Data.SQLite. Any volunteers are welcome to do so, unfortunately I am out of time to do so before next year.
TL;DR
The solution is to force a GC after your call to SQLiteConnection.Close() and before your call to File.Delete().
Here is the sample code:
string filename = "testFile.db";
SQLiteConnection connection = new SQLiteConnection("Data Source=" + filename + ";Version=3;");
connection.Close();
GC.Collect();
GC.WaitForPendingFinalizers();
File.Delete(filename);
Good luck with it, and I hope it helps
Just GC.Collect() didn't work for me.
I had to add GC.WaitForPendingFinalizers() after GC.Collect() in order to proceed with the file deletion.
Had a similar issue, though the garbage collector solution didn't fix it.
Found disposing of SQLiteCommand and SQLiteDataReader objects after use saved me using the garbage collector at all.
SQLiteCommand command = new SQLiteCommand(sql, db);
command.ExecuteNonQuery();
command.Dispose();
The following worked for me:
MySQLiteConnection.Close();
SQLite.SQLiteConnection.ClearAllPools()
More info:
Connections are pooled by SQLite in order to improve performance.It means when you call Close method on a connection object, connection to database may still be alive (in the background) so that next Open method become faster.When you known that you don't want a new connection anymore, calling ClearAllPools closes all the connections which are alive in the background and file handle(s?) to the db file get released.Then db file may get removed, deleted or used by another process.
In my case I was creating SQLiteCommand objects without explicitly disposing them.
var command = connection.CreateCommand();
command.CommandText = commandText;
value = command.ExecuteScalar();
I wrapped my command in a using statement and it fixed my issue.
static public class SqliteExtensions
{
public static object ExecuteScalar(this SQLiteConnection connection, string commandText)
{
using (var command = connection.CreateCommand())
{
command.CommandText = commandText;
return command.ExecuteScalar();
}
}
}
The using statement ensures that Dispose is called even if an exception occurs.
Then it's a lot easier to execute commands as well.
value = connection.ExecuteScalar(commandText)
// Command object created and disposed
I was having a similar problem, I've tried the solution with GC.Collect but, as noted, it can take a long time before the file becomes not locked.
I've found an alternative solution that involves the disposal of the underlying SQLiteCommands in the TableAdapters, see this answer for additional information.
I've been having the same problem with EF and System.Data.Sqlite.
For me I found SQLiteConnection.ClearAllPools() and GC.Collect() would reduce how often the file locking would happen but it would still occasionally happen (Around 1% of the time).
I've been investigating and it seems to be that some SQLiteCommands that EF creates aren't disposed and still have their Connection property set to the closed connection. I tried disposing these but Entity Framework would then throw an exception during the next DbContext read - it seems EF sometimes still uses them after connection closed.
My solution was to ensure the Connection property is set to Null when the connection closes on these SQLiteCommands. This seems to be enough to release the file lock. I've been testing the below code and not seen any file lock issues after a few thousand tests:
public static class ClearSQLiteCommandConnectionHelper
{
private static readonly List<SQLiteCommand> OpenCommands = new List<SQLiteCommand>();
public static void Initialise()
{
SQLiteConnection.Changed += SqLiteConnectionOnChanged;
}
private static void SqLiteConnectionOnChanged(object sender, ConnectionEventArgs connectionEventArgs)
{
if (connectionEventArgs.EventType == SQLiteConnectionEventType.NewCommand && connectionEventArgs.Command is SQLiteCommand)
{
OpenCommands.Add((SQLiteCommand)connectionEventArgs.Command);
}
else if (connectionEventArgs.EventType == SQLiteConnectionEventType.DisposingCommand && connectionEventArgs.Command is SQLiteCommand)
{
OpenCommands.Remove((SQLiteCommand)connectionEventArgs.Command);
}
if (connectionEventArgs.EventType == SQLiteConnectionEventType.Closed)
{
var commands = OpenCommands.ToList();
foreach (var cmd in commands)
{
if (cmd.Connection == null)
{
OpenCommands.Remove(cmd);
}
else if (cmd.Connection.State == ConnectionState.Closed)
{
cmd.Connection = null;
OpenCommands.Remove(cmd);
}
}
}
}
}
To use just call ClearSQLiteCommandConnectionHelper.Initialise(); at the start of application load.
This will then keep a list of active commands and will set their Connection to Null when they point to a connection that is closed.
Try this... this one tries all the above codes... worked for me
Reader.Close()
connection.Close()
GC.Collect()
GC.WaitForPendingFinalizers()
command.Dispose()
SQLite.SQLiteConnection.ClearAllPools()
Hope that helps
Use GC.WaitForPendingFinalizers()
Example:
Con.Close();
GC.Collect();`
GC.WaitForPendingFinalizers();
File.Delete(Environment.CurrentDirectory + "\\DATABASENAME.DB");
I believe the call to SQLite.SQLiteConnection.ClearAllPools() is the cleanest solution. As far as I know it is not proper to manually call GC.Collect() in the WPF environment. Although, I did not notice the problem until I have upgraded to System.Data.SQLite 1.0.99.0 in 3/2016
Had a similar problem. Calling Garbage Collector didn't help me. LAter I found a way to solve the problem
Author also wrote that he did SELECT queries to that database before trying to delete it. I have the same situation.
I have the following code:
SQLiteConnection bc;
string sql;
var cmd = new SQLiteCommand(sql, bc);
SQLiteDataReader reader = cmd.ExecuteReader();
reader.Read();
reader.Close(); // when I added that string, the problem became solved.
Also, I don't need to close database connection and to call Garbage Collector. All I had to do is to close reader which was created while executing SELECT query
Best answer that worked for me.
dbConnection.Close();
System.Data.SQLite.SQLiteConnection.ClearAllPools();
GC.Collect();
GC.WaitForPendingFinalizers();
File.Delete(Environment.CurrentDirectory + "\\DATABASENAME.DB");
The reason for this seems to be a feature called "Pooling".
Appending "Pooling=false" to the connection string causes the DB-File to be released with "connection.Close()".
See the FAQ on connection pooling here:
https://www.devart.com/dotconnect/sqlite/docs/FAQ.html#q54
I was struggling with the similar problem. Shame on me... I finally realized that Reader was not closed. For some reason I was thinking that the Reader will be closed when corresponding connection is closed. Obviously, GC.Collect() didn't work for me.
Wrapping the Reader with "using: statement is also a good idea. Here is a quick test code.
static void Main(string[] args)
{
try
{
var dbPath = "myTestDb.db";
ExecuteTestCommand(dbPath);
File.Delete(dbPath);
Console.WriteLine("DB removed");
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
Console.Read();
}
private static void ExecuteTestCommand(string dbPath)
{
using (var connection = new SQLiteConnection("Data Source=" + dbPath + ";"))
{
using (var command = connection.CreateCommand())
{
command.CommandText = "PRAGMA integrity_check";
connection.Open();
var reader = command.ExecuteReader();
if (reader.Read())
Console.WriteLine(reader.GetString(0));
//without next line database file will remain locked
reader.Close();
}
}
}
Maybe you don't need to deal with GC at all. Please, check if all sqlite3_prepare is finalized.
For each sqlite3_prepare, you need a correspondent sqlite3_finalize.
If you don't finalize correctly, sqlite3_close will not close the connection.
This works for me but i noticed sometimes journal files -wal -shm are not deleted when the process is closed. If you want SQLite to remove -wal -shm files when all connection are close the last connection closed MUST BE non-readonly. Hope this will help someone.
I was using SQLite 1.0.101.0 with EF6 and having trouble with the file being locked after all connections and entities disposed.
This got worse with updates from the EF keeping the database locked after they had completed.
GC.Collect() was the only workaround that helped and I was beginning to despair.
In desperation, I tried Oliver Wickenden's ClearSQLiteCommandConnectionHelper (see his answer of 8 July). Fantastic. All locking problems gone!
Thanks Oliver.
Waiting for Garbage Collector may not release the database all time and that happened to me. When some type of Exception occurs in SQLite database for example trying to insert a row with existing value for PrimaryKey it will hold the database file until you dispose it. Following code catches SQLite exception and cancels problematic command.
SQLiteCommand insertCommand = connection.CreateCommand();
try {
// some insert parameters
insertCommand.ExecuteNonQuery();
} catch (SQLiteException exception) {
insertCommand.Cancel();
insertCommand.Dispose();
}
If you not handle problematic commands' exceptions than Garbage Collector cannot do anything about them because there are some unhandled exceptions about these commands so they are not garbage. This handling method worked well for me with waiting for garbage collector.
I'm using the Booksleeve library in a C#/ASP.NET 4 application. Currently the RedisConnection object is a static object across my MonoLink class. Should I be keeping this connection open, or should I be open/closing it after each query/transaction (as I'm doing now)? Just slightly confused. Here's how I'm using it, as of now:
public static MonoLink CreateMonolink(string URL)
{
redis.Open();
var transaction = redis.CreateTransaction();
string Key = null;
try
{
var IncrementTask = transaction.Strings.Increment(0, "nextmonolink");
if (!IncrementTask.Wait(5000))
{
transaction.Discard();
throw new System.TimeoutException("Monolink index increment timed out.");
}
// Increment complete
Key = string.Format("monolink:{0}", IncrementTask.Result);
var AddLinkTask = transaction.Strings.Set(0, Key, URL);
if (!AddLinkTask.Wait(5000))
{
transaction.Discard();
throw new System.TimeoutException("Add monolink creation timed out.");
}
// Run the transaction
var ExecTransaction = transaction.Execute();
if (!ExecTransaction.Wait(5000))
{
throw new System.TimeoutException("Add monolink transaction timed out.");
}
}
catch (Exception ex)
{
transaction.Discard();
throw ex;
}
finally
{
redis.Close(false);
}
// Link has been added to redis
MonoLink ml = new MonoLink();
ml.Key = Key;
ml.URL = URL;
return ml;
}
Thanks, in advance, for any responses/insight. Also, is there any sort of official documentation for this library? Thank you S.O. ^_^.
According to the author of Booksleeve,
The connection is thread safe and intended to be massively shared;
don't do a connection per operation.
Should I be keeping this connection open, or should I be open/closing
it after each query/transaction (as I'm doing now)?
There is probably a little overhead if you will open a new connection each time you want to make a query/transaction and although redis is designed for high level of concurrently connected clients, there might be performance problems if their number is around tens of thousands. As far as I know connection pooling should be done by the client libraries (because redis itself doesn't have this functionality), so you should check if booksleeve supports this stuff. Otherwise you should open the connection when your application starts and keep it open for it's lifetime (in case you don't need parallel clients connected to redis for some reason).
Also, is there any sort of official documentation for this library?
The only documentation I was able to find regarding how to use it was tests folder in it's source codes.
For reference (continuing #bzlm's answer), I created a Singleton that always provides the same Redis connection using BookSleeve (if it's closed, it's being created. Else, the existing connection is being served).
Look at this: https://stackoverflow.com/a/8777999/290343
You consume it like that:
RedisConnection connection = Redis.RedisConnectionGateway.Current.GetConnection();
Can you guys let me know the way of handling transactions in asp.net?
i.e. I have a few queries (Present in different functions and called under various situations) that have to be executed as a whole. So, how should I go about it?
Not sure of the syntax and the method/practice for writing the statements in .net (commit, rollback etc).
Kindly let me know. Also, plz point me to some good articles if possible. Thanks!!!
I recommend using TransactionScope, because you can use it no mater what DB you are using. You can even do distributed transactions (operations against multiple databases within the same transaction) with it.
You can refer to a link for a code example, but in general, you do this:
try
{
using (TransactionScope scope = new TransactionScope())
{
using (MySqlConnection connection1 = new MySqlConnection (connectionString))
{
// Opening the connection automatically enlists it in the
// TransactionScope as a lightweight transaction.
connection1.Open();
// create the DB commands and perform the DB operations
.
.
.
// The Complete method commits the transaction. If an exception has been thrown,
// Complete is not called and the transaction is rolled back.
scope.Complete();
}
}
}
catch (Exception e)
{
// something went wrong, handle the exception accordingly. Note
// that since we did not call TransactionScope.Complete, nothing
// gets committed to the DB.
}
Here's another starter for TransactionScope: Implementing an Implicit Transaction using Transaction Scope
Don't know much about TransactionScope, but I just use the normal IDbTransaction like this:
IDbConnection conn = null;
IDbCommand cmd = null;
IDbTransaction tran = null;
try
{
conn = DatabaseUtil.GetConnection(); //Get the connection somehow
cmd = conn.CreateCommand();
tran = conn.BeginTransaction();
cmd.Transaction = tran;
//Do your DB Work
tran.Commit();
}
catch (SystemException ex)
{
tran.Rollback();
}
finally
{
if (conn != null) conn.Close();
}
With the IDb classes you are DB independent too to a certain degree.
If its a local transaction you can also use ado.net's transaction object. TransactionScope will handle distributed transactions if needed but requires MSDTC to be configured if a transaction is promoted to a distributed transaction.
http://msdn.microsoft.com/en-us/library/2k2hy99x.aspx
Both are in the System.Transactions Namespace http://msdn.microsoft.com/en-us/library/system.transactions.aspx