I'm using NH Prevalence Cache provider with happiness from years, but recently, my team, started to fall in some data
incorrectness which I can't yet explain...
We setup the prevalence by setting up the cache provider and
setting the prevalenceBase folder to AppDomain.CurrentDomain.BaseDirectory
setting a default expiration of 120
each cache registration in mappings ha a region name
The cache seems to work, but if the application is recycled, the data which will be returned by NHibernate is incorrect
with a valid identifier, it provides data which seems owned by another entity.
If we delete the .snapshot file in the folder (AppDomain.CurrentDomain.BaseDirectory) then everything starts to work fine,
until the next recycle wher ethe issue will be represented.
Any one has got the same issue?
Any one can help with this issue?
Sure I forget or ignore something, but someone who can explain better how to setup prevalence will be appreciated
Thanks in advance
Related
Problem: I created 10 AlwaysOn Availability Groups with SQL Server without a problem. Suddenly, it stopped worked and I kept getting this ONLY on the "create the listener" part:
Msg 19471, Level 16, State 0, Line 9
The WSFC cluster could not bring the Network Name resource with DNS name 'L_MyListener' online. The DNS name may have been taken or have a conflict with existing name services, or the WSFC cluster service may not be running or may be inaccessible. Use a different DNS name to resolve name conflicts, or check the WSFC cluster log for more information.
Sometimes I also got Msg 19476. This was all maddening because one moment I was creating listeners and availability groups, feeling like a guru, and then everything stopped and I lost hours of time.
So how do you solve this? Of course, Microsoft's own suggested text in the above error description was NOT helpful.
Apparently, each listener is really creating a mini "computer" in Active Directory if you look. And... here's the kicker, a domain user can only join a computer to a domain a limited number of times and that default is 10. Who would have thought that adding listeners equates with joining users to a domain!???! Microsoft really should have made this listener thing more intuitive, at least in their description text of possible problems.
Well, on your Domain Controller, open ADSI Edit, configure it the first time to look at your default naming context of your domain, like "DC=yourname..." with the CN= rows below that. Now, right click on the "DC=" line, choose Properties and navigate down to ms-DS-MachineAccountQuota and increase the limit from 10 to something else like 100.
You may need to run "GPUPDATE /FORCE" on the SQL Servers where you want to try again to add the listener. You may also have to clean up the mess it left (i.e. delete and restore the bad attempt at setting up your group and listener) before you try again.
With SQL Server 2016 supposedly going to require each database be in its own group, with its own listener, people will hit this limit of 10 quite easily!
I hope this helps you. If so, please mark this as the answer on the left. Of course, there are other reasons why people may get this error, as in the Microsoft error now but this whole post is for people who had it working just fine and then suddenly it stopped.
I'm using MigratorDotNet to manage Rails-style migrations for my web app. I have a workflow where, if I delete all the tables in the database, I can access an installation view that will run MigratorDotNet and create all the necessary tables.
This works locally. For some reason, when I upload my code to my Arvixe hosting, the migrations just never run. I get this odd error:
There is already an object named 'SchemaInfo' in the database.
This is odd because, prior to running migrations, I manually deleted all the tables in the database (to make sure it wasn't left over from a previous install).
My code essentially boils down to:
new Migrator.Migrator("SqlServer", connectionString.ToString(), migrationsAssembly).MigrateToLastVersion();
I've already verified by logging that the connection string is correct (production/hosting settings), and the assembly is correctly loaded (name and version).
Works locally, but not on Arvixe. How do I troubleshoot this?
This is a dark day.
It turns out (oddly) that the root cause was my hosting company used a schema other than dbo for my database. Because of this, the error message I saw (SchemaInfo already exists) was talking about their table.
My solution, unfortunately, was to rip out MigratorDotNet and go with FluentMigator instead. not only did this solve the problem, but it also gave me a more intelligible error message (one referring to the schema names).
While it doesn't seem possible to auto-set the schema, and while I need to switch the schema on my dev vs. production machine, it's still a solvable problem (and a better API, IMO). I googled, but did not find any way to change the default schema in migratordotnet.
I'm sorry for the issues that you were having. On shared hosting, unfortunately the only way that we may be able to change the schema is manually. If you are still looking for a solution that requires our assistance, please forward your ticket ID to qa .at. arvixe.com as well as arvand .at. arvixe.com and we can look into the best way to resolve this.
We are using appfabric as the 2ndlevel cache for an NHibernate asp.net application comprising a customer facing website and an admin website. They are both connected to the same cache so when admin updates something, the customer facing site is updated.
It seems to be working OK - we have a CacheCLuster on a seperate server and all is well but we want to enable localcache to get better performance, however, it dosnt seem to be working.
We have enabled it like this...
bool UseLocalCache =
int LocalCacheObjectCount = int.MaxValue;
TimeSpan LocalCacheDefaultTimeout = TimeSpan.FromMinutes(3);
DataCacheLocalCacheInvalidationPolicy LocalCacheInvalidationPolicy = DataCacheLocalCacheInvalidationPolicy.TimeoutBased;
if (UseLocalCache)
{
configuration.LocalCacheProperties =
new DataCacheLocalCacheProperties(
LocalCacheObjectCount,
LocalCacheDefaultTimeout,
LocalCacheInvalidationPolicy
);
// configuration.NotificationProperties = new DataCacheNotificationProperties(500, TimeSpan.FromSeconds(300));
}
Initially we tried using a timeout invalidation policy (3mins) and our app felt like it was running faster. HOWEVER, we noticed that if we changed something in the admin site, it was immediatley updated in the live site. As we are using timeouts not notifications, this demonstrates that the local cache isnt being queried (or is, but is always missing).
The cache.GetType().Name returns "LocalCache" - so the factory has made a local cache.
Running "Get-Cache-Statistics MyCache" in PS on my dev environment (asp.net app running local from vs2008, cache cluster running on a seperate w2k8 machine) show a handful of Request Counts. However, on the Production environment, the Request Count increases dramaticaly.
We tried following the method here to se the cache cliebt-server traffic... http://blogs.msdn.com/b/appfabriccat/archive/2010/09/20/appfabric-cache-peeking-into-client-amp-server-wcf-communication.aspx but the log file had nothing but the initial header in it - i.e no loggin either.
I cant find anything in SO or Google.
Have we done something wrong? Have we got a screwy install of AppFabric - we installed it via WebPlatform Installer - I think?
(note: the IIS box running ASp.net isnt in yhe cluster - it is just the client).
Any insights greatfully received!
Which DataCache methods are you using to read from the cache? Several of the DataCache methods will always make a hit against the server regardless of local cache being configured. You pretty much have to make sure you only use Get if you want the local cache to be leveraged.
This is one my biggest nits with AppFabric Caching. They don't explain any of this to you and so when you begin to rely on local caching you begin to fall into these little pitfalls because you do not think you're paying a penalty for talking to the service, transferring data over the wire and deserializing objects, but you are.
The worst thing is, I could understand having to talk to the service to make sure the local cache represents the latest data. I can even understand transferring the data back so that multiple calls are not made. What I can not understand for the life of me though is that even if the instance in the local cache is verified to still be the current version that came back from the cache, they still deserialize the object from the wire rather than just returning the instance that's in memory already. If your objects are large/complex this can hurt a lot.
After days and days of looking into why we get so many Local Cache misses we finally solved it:
There is a bug with local cache in AppFabric v 1.1 that is fixed in CU4, see http://support2.microsoft.com/kb/2800726/en-us
Make sure that the Microsoft.ApplicationServer.Caching.Client.dll used by your application is also updated. We had CU4 installed on the machine but got the Client.dll without CU4 from a NuGet package in our application. In our case a simple NuGet package update made everything work.
After installing CU4 and making sure that the Client.dll was also updated we reduced our reads towards the AppFabric Host by a lot, due to Local Cache hits increasing. yay!
Have you tried using a nhibernate profiler? http://nhprof.com/
There is also this:
http://mdcadmintool.codeplex.com/
It's a nice way to manage and view the cache.
Both of these may help in debugging the issue.
I have almost exactly this problem. I say, almost exactly because the answer that worked for this gentleman did nothing whatsoever for me. I can open my own database and see all of the lovely RS data sitting there staring at me but the actual Reporting Services installation still can't. This all came about because of precisely what he said. We accidentally left the password policy on on the Reporting Services account and it expired. When I changed it the whole thing went kaputt. I'm still getting the "key cannot be used in current state" error message even after dropping all encrypted data from the RS installation. I have no access to the Report Manager to reset encrypted information. Has anyone got any suggestions?
EDIT: In continuing my research I found this suggestion. It's not that.
Well... here's the thing.
I eventually tried creating a whole new user to take charge of the SSRS operations. I also remembered to update those details on our live data server. (I did this first and it failed to work as it was still telling me the key could not be used then.)
I guess that there must be something that prevents the reassignment of the SSRS gofer account's password. The new user is set up identically and works perfectly. So that's what cleared it up for me but I'm a little irritated that I still don't know exactly why...
I'm trying to track down a problem on our test environment. Previously it was set to use InProc Session State Type, but I've added in the SQLServer type for one specific Web App. I did this because we use the SQLServer type in our production environment and I want our test env to match as closely as possible.
However, after changing it to SQLServer I do not get any errors when trying to store unserializable data in session like I would expect. It works just fine, even though I would think it shouldn't. I'm a relative newbie when it comes to configuring this, but from the various tutorials I googled, I thought I covered all the bases.
I was wondering if there's any code snippets to verify which session state type an application is actively using.
Thanks
Ok, found it by accessing:
System.Web.SessionState.HttpSessionState.Mode
Was also able to look at the tables in the ASPState database to see sessions being added/removed.
Apparently it was just the test code we were using that we expected to break that was not behaving as we expected..