[jbosscache-dev] Fixing PojoCache tutorial - exception from getState

[Galder Zamarreno]

Alternatively, if that code is behaving as it should, why is there that 
"hack" to prevent in memory state transfer for the GUI? So that it 
always starts empty?

Galder Zamarreno wrote:
> Hi,
> 
> I'm trying to fix the tutorial for PojoCache. This works slightly 
> different because you have an instance of the GUI and then the code 
> entered via ./runShellDemo.sh
> 
> I have noted that in JBossCacheView, there following happens before 
> starting the cache:
> 
> // hack to prevent a state transfer for now
> cache.getConfiguration().setFetchInMemoryState(false);
> 
> pojocache.bsh which is loaded via ./runShellDemo.sh still uses the same 
> replSynch-service.xml descriptor but it does not set fetch in memory to 
> false.
> 
> So, if you start the GUI first, and then execute ./runShellDemo.sh and 
> then type sourceRelative("pojocache.bsh");, you get an exception like this:
> 
> "Caused by: org.jboss.cache.CacheException: Cache instance at 
> 127.0.0.1:33058 cannot integrate state since state provider could not 
> provide state due to org.jboss.cache.CacheException: Cache instance at 
> 127.0.0.1:33056 is not configured to provide state"
> 
> Now, i'm debating the suitability of the following code in 
> StateTransferManager.getState:
> 
> if (!fetchPersistentState && !fetchTransientState)
> {
> e = new CacheException("Cache instance at " + cache.getLocalAddress() + 
> " is not configured to provide state");
> }
> 
> Documentation says: "FetchInMemoryState: Whether or not to acquire the 
> initial in-memory state from existing members. "
> 
> It does not say anything about giving a state. There's nothing saying 
> that a cache not configured to fetch should not be able to give it. I 
> mean, a cache could potentially be configured not to retrieve transient 
> state on startup, but another cache could be configured to do so and 
> should be able to retrieve it from the first cache started, shouldn't it?
> 
> Cheers,
> 

-- 
Galder Zamarreño
Sr. Software Maintenance Engineer
JBoss, a division of Red Hat