We have a .NET application that runs on Windows Azure and uses NHibernate to connect to a SQL Azure database. Sometimes it's necessary to add retry logic to handle transient failures in SQL Azure as described for example here -
http://social.technet.microsoft.com/wiki/contents/articles/retry-logic-for-transient-failures-in-sql-azure.aspx
Can someone point me to a way in doing this with NHibernate? Ideally I'd like to do this at the NHibernate level and not wrap every single call; I was able to do this for another ORM, .netTiers (http://nettiers.com) as I outline here -
http://blog.ehuna.org/2010/01/how_to_stop_getting_exceptions.html
I did search and found some answers that mention using a custom implementation of the IDbCommand interface -
Intercept SQL statements containing parameter values generated by NHibernate
But I'm not sure this works with NHibernate 3.2 and I'm looking for a clear example I could modify.
How could I make NHibernate retry calls to SQL Azure automatically? Let's say 3 retries, with 100ms wait between each - after the 3 retries, if still failing, we should throw the exception.
I've released a library that takes care of this:
https://github.com/robdmoore/NHibernate.SqlAzure
This is not a complete running example, but the files you need are here
https://github.com/craigvn/NHibernateRetryable
Maybe this can help you out:
http://www.objectreference.net/post/NHibernate-and-Execution-Plans.aspx. Here there is a class that you can download and play with it, with some overrides.
Also check this link as well: http://elliottjorgensen.com/nhibernate-api-ref/NHibernate.Driver/SqlClientDriver.html
I hope it helps in anyway, I'm going thru a similar situation.
Regards,
Related
I am currently working on a project which must be able, dynamically, to be able to connect on different diagrams according to the connected user.
I am using symfony 3.4 and api_platform.
To achieve my goals, I thought I would intercept the execution of requests with a subscriber or an event listener and modify the ORM diagram (if possible).
Have you ever encountered this problem?
Do you think this is possible this way? or do you have an idea of how to do it differently?
Thank you
In a flyway migration a FlyWayException can be throw according to differents cases : during a migration failure, if the given database url can not be found etc.
Everytime it's a FlyWayException with a JdbcSQLException as cause. But in my app I'd like to isolate these cases in order to provide differents behaviors.
Is there any way to do this ?
I can see that a JdbcSQLException contains a SQLState, maybe it can be a solution, but I don't know if it's the best one.
It is never good to parse out SQL exceptions as they may change from version to version of the database. I would submit a feature request to Flyway to have specific exceptions instead of one generic FlyWayException: https://github.com/flyway/flyway/issues.
In NHibernate, I have show_sql turned on for running unit tests. Each of my unit tests clears the database and refills it, and this results in lots of sql queries that I don't want NHibernate to output.
Is it possible to control show_sql without destroying the SessionFactory? If possible, I'd like to turn it off when running setup for a test, then turn it on again when the body of the test starts to run.
Is this possible?
The only place you can set this is when building a NHibernate.Cfg.Configuration.
Once you've created a SessionFactory from your Configuration, there's no way to access the configuration settings, which I think is one of the reasons for using a factory pattern: to ensure that instances once successfully built can't be messed up by runtime re- or mis-configuration.
If you really need that feature, get the NH source code and find the place where the show_sql setting is evaluated.
Another option although it may/may not be as good is to use NHProf and just initialise NHProf when testing.
NHProf doesn't log setting/clearing database just queries used.
I have an existing NServiceBus 2.6 application that I want to start moving to 3.0. I'm looking for the minimum change upgrade in the first instance. Is this as simple as replace the 2.6 DLLs with the 3.0 Nuget packages or are there other considerations?
For the most part the application migration is quite straight forward, but depending on your configuration and environment, you may need to make the following changes:
The new convention over configuration for endpoints may mean you will need to rename your endpoints to match your queue names (#andreasohlund has a good post about this).
persistence of saga, timeouts, subscriptions etc. now defaults to RavenDb, so if you use SQL Server to persist data, you need to make sure you have to correct profile and endpoint configuration. For SQL Server storage, make sure you add a reference to NServiceBus.NHibernate as it is no longer part of the core.
Error queues are now referenced differently using different configuration ie. use MessageForwardingInCaseOfFaultConfig instead of the regular MsmqTransportConfig error property. You should still be able to use it, but it will look for the MessageForwardingInCaseOfFaultConfig first.
Other than that, I don't think you need to do anything else to get you upgrade working. I modified some of my message definitions to take advantage of the new ICommand and IEvent interfaces as a way communicatinf intent more clearly.
Anyway, I'm sure there will be some cases that are specific to your environment that will require different changes but I hope this helps a bit.
So I am having problems getting NHibernate intergated in my MVC project. I therefore, installed the NHProfiler and initialized it in the Global.asax.cs file (NhibernateProfiler.Initialize();).
However, all I can see in the NHProf is a Session # and the time it took to come up. But selecting it or any other operations doesn't show me any information about the connection to the database or any information at all in any of the other windows such as:
- Statements, Entities, Session Usage
The Session Factory Statistics only shows Start time, execution time, and thats it.
Any thoughts.
Do you have any custom log4net configuration? Just thinking that might be overwriting NHProf's log4net listener after startup. If you refresh the page (and hence start another session*), does NHProf display another Session start? Also verify that your HibernatingRhinos.Profiler.Appender.dll (or HibernatingRhinos.Profiler.Appender.v4.0.dll if you're using .NET 4) is the same one as the current version of NHProf.
* I'm assuming that you're using Session-per-Request since this is a web app.