Re: Fault tolerance on clusters

Hi Nadir,
OSCache is not a full fledged cluster cache. It solves only few important problems in cluster. One of them is to see such that there is never any stale data in the system. Basically oscache just sends messages to other nodes in the cluster, only for flush events. This means the cache in each node is independent of each other and they may not be in sync.

OSCache does not solve the problem of fault tolerance and only partially solves the problem of availability. I thin OSCache is alight weight cluster cache which deals only with simple stuff.

If you want to use the fully replicated cache that works in a cluster, I donno if oscache is the solution. If you search the mailing list, Chris Miller explained the cache feature in detail. That would probably help you better.

Others, correct me if I am wrong.

There are other caches like Tangosol (which cost few 1000s of $$$$ :)).

Praveen
  ----- Original Message ----- 
  From: Nadir T. 
  To: [email protected] 
  Sent: Monday, December 22, 2003 7:04 AM
  Subject: [Opensymphony-oscache] Fault tolerance on clusters


  Hye,
       I'm still a newbie in OsCache, but I would like to know if it handles fault tolerance on clusters, that is, lets say I have two clusters (C1 and C2) running an O/R mapping tool such as Hibernate or OJB with OsCache. Considering the following situation:
     1. Begin Transaction
     2. Write data in C1 cache
     3. Commit Transaction (flush is made here)
     4. C1 fails before sending changes to database and cluster C2

  When C1 recovers, to who does he sends changes? Both of them (database and C2)? Only to database? None of them?

  Does OSCache makes local caching persistent to protect against faults in cluster?

  P.S: Sorry my bad english

  Thanks,
  Nadir




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