We are using memcached 1.2.4 via enyim and are finding it difficult to get some objects to cache. If I watch the memcache console it just says 'NOT_STORED'.
I think we need to use [serializable] but that doesnt always work. I cant find any documentation or relevant google hits.
Any one here got any clues?
Thanks
Strongly recommend upgraded your version of memcached.
NOT_STORED means just that, your data was not stored. If you are using the add command to store data, this means that there's already data under that key. If you are using replace it means that there's not data under that key. You probably mea set.
Thanks and sorry for the late reply.
The problem was two-fold. Using [Serializable] was not adequate for some objects so we have to implement ISerializable. We were also using ADD rather than SET.
From memory I couldn't find an upgrade for memcached and once we fixed the above it worked.
Cheers
I had this problem to...I was running something like:
var = CACHE.fetch("key_name",1.day,true) do
ModelName.find_by_id(id)
end
So I was having active record find a record for me but I didn't know that memcached doesn't store nil values. What was happening was active record was returning nil because it couldn't find the record and therefore I was telling memcache to store a nil value. The fix was simply this:
var = CACHE.fetch("key_name",1.day,true) do
ModelName.find_by_id(id) || ""
end
I use Ruby to code with. Hope this helps.
Related
I'm programming my fist SwiftApp got stuck setting up Core data. Since I'm integrating it into existing code I can't have Xcode set it up on Prohect init anymore. Furthermore I als want to understand what the lines of code actually do. Since all Core libraries are secret I am stuck with Apple's Docs which are not very clear on the matter.
Pfew... with that out of the way here is the question; What is the significance of the name passed to...
let container = NSPersistentContainer(name: "Core_Data")
...in the App Delegate file. I had set it up before but during compilation Xcode complained that it could not find the specified Name's module. Changing it to my project's name, the core data file I had created or the name of the Database passed to the menu when adding a Core Data file did not seem to help at all. Searching the web and a few tutorials people just fly over it and it is still very much unclear to me.
Any help would be much appreciated!
The string passed there is used for two things. If you were to pass the string Foo, Core Data would attempt:
To find the data model by looking for Foo.xcdatamodel or Foo.xcdatamodeld.
To find (or create) the persistent store, using the name Foo.sqlite.
Even an incorrect string value (i.e. one that doesn't match the name of your data model) should not cause a compilation error. It might cause an error at run time if iOS can't find the named data model.
Cache2k looks like a very promising caching implementation. Unfortunately the documentation is very limited, which is why I need some help with the following issue. I am using the latest version 0.26-BETA.
According to the documentation the cache is supposed to be created like this:
Cache<String,String> c =
CacheBuilder.newCache(String.class, String.class).build();
String val = c.peek("something");
assertNull(val);
c.put("something", "hello");
val = c.get("something");
assertNotNull(val);
c.destroy();
Unfortunately at least 2 of these methods are deprecated, including the CacheBuilder class itself. I therefore tried creating the cache like this:
org.cache2k.Cache<String, Object> newCache = Cache2kBuilder.of(String.class, Object.class)
.name(cacheKey.toString())
.entryCapacity(100000)
.eternal(true)
.build();
This however throws the "java.lang.UnsupportedOperationException: loader not set" exception.
The question therefore is: how am I supposed to build the cache so that I do not get this exception?
EDIT:
This gives me the same exception:
org.cache2k.Cache<Object, Object> newCache =
CacheBuilder.newCache(Object.class, Object.class)
.eternal(true)
.build();
EDIT #2:
Just one more note: When I copy&paste the code from the wiki page I get an error - as can be seen in the image below.
With what jdk version are you testing? I'll try just removing the <> that are causing the problem for now.
Thanks very much in advance!
Michael
Cache2k looks like a very promising caching implementation.
Thanks :)
According to the documentation the cache is supposed to be created like this
There are new interfaces in place. The deprecated one is still there to support users of old cache2k versions. That will get cleared up in the next weeks. Sorry for the confusion.
Please take a look here for the latest getting started information:
https://github.com/cache2k/cache2k/blob/master/doc/src/docs/asciidoc/user-guide/sections/_start.adoc
This however throws the "java.lang.UnsupportedOperationException: loader not set" exception.
The question therefore is: how am I supposed to build the cache so that I do not get this exception?
Short answer: Either use cache.peek() or wait for 0.27, since then it is working with cache.get() transparently.
Longer answer: In our own applications I use cache.get() only when a loader is defined and cache.peek() when no loader is defined or when I want to inspect the cache only. Reserving cache.get() only for the read through usage, seemed like a good idea. However, I reasoned that it might be a caveat for new users, so I change that behavior and align it to other cache solutions.
Answer to Edit 2:
For an untyped cache use the factory method Cache2kBuilder.forUnkownTypes(). Constructing the anonymous class is only needed for specific types.
I'm learning from breeze-zza-mongodb sample.
I get some problems when i try to use the saveChanges() function from breeze.
This is the error i get:
"TypeError: Cannot read property 'update' of null at... node_modules\breeze-mongodb\mongoSaveHandler.js : 229:20 at Array.forEach"
Any of you tried and got this error? I searched Google for a bit longer but i can't find this issue. And if i try to manager.getChanges() and put the changes in array, i get my entity with modified state.
The guys from breeze didn't covered this part and i'm completly blind in this. Thank you for your time guys.
I solved my problem. I included the modules in VS so i can debug and i noticed that breeze misnamed my collection name for some reason adding an s at the end.
Anyway.. for now i just removed that, and it works. I will dig deeper to see where and why is breeze adding an s at the end of my collection name because i want to treat the cause, not the effect. Thanks.
In the previous version, 0.6.4, I can use Meteor._RemoteCollectionDriver.mongo.db to access to mongodb directly. Because I need to use Mongo's Grid to store files, which I cannot do easily with Meteor collections. With the new version, Meteor._RemoteCollectionDriver.mongo.db is not available anymore. Does anyone know where can I have that?
Thanks
I think they've moved to a singleton style class, see https://github.com/meteor/meteor/blob/devel/packages/mongo-livedata/remote_collection_driver.js.
Be warned this isn't upgrade proof either like before, as with all the methods beginning with _:
MongoInternals.defaultRemoteCollectionDriver
I have a fairly simple question to which I cannot seem to find the answer for. I have a silverlight app with Ria Services. In the DomainService class I have an update method like below:
public void UpdateConversationState(ConversationState currentConversationState)
{
var original = ChangeSet.GetOriginal(currentConversationState);
if (original != null)
ObjectContext.ConversationStatesRepository.AttachAsModified(currentConversationState, original);
else
ObjectContext.ConversationStatesRepository.Attach(currentConversationState);
currentConversationState.UpdDat = DateTime.Now;
if(original.Name != currentConversationState.Name)
//Do something extra
}
The problem is that the Name property is always empty. In fact every field except for the Id has default values. I've tried searching for how the GetOriginal method works, but cannot find any help. It seems to mee like it tries to rebuild the original object on the server, based on the changes that are sent back from client to server.
Or maybe anyone knows a better way to check if a certain property of an object has been changed during an update? I could off course compare it to the value in the database, but it seems like I should avoid this extra call to the database.
Any help is again much appreciated :-)
EDIT:
Just found out about the RoundTripOriginalAttribute. This seems to do the trick. Am I the only one by the way that think RIA could be documented a little bit better?
Well, I've been also looking for a way track entity changes with EF4 and after some googling I've found that you need to apply the "RoundTripOriginal" attribute to the properties of the entity you want to track, because RIA (by default) does not send the original values back to the server.
I still have some concerns on this and I asked some of the gurus:
http://forums.silverlight.net/forums/t/218332.aspx
This worked for me, but I still don´t think is the best way out of it.
Hope this helps.