Hi Imesh, Thank you for the explanations.
I'm +1 for the overall model. Thanks. On 27 Nov 2014 07:19, "Imesh Gunaratne" <im...@apache.org> wrote: > Hi, > > On Wed, Nov 26, 2014 at 5:27 PM, Udara Liyanage <ud...@wso2.com> wrote: > >> Reading from registry frequently might be more expensive than distributed >> locking since a number of database queries are executed. >> +1 for distributed collections. >> >> Are we going to use Hazlecast or any other framework ? >> > > We are planning to use Carbon clustering (abstraction) which internally > use Hazelcast. > > On Wed, Nov 26, 2014 at 5:30 PM, Akila Ravihansa Perera < > raviha...@wso2.com> wrote: > >> >>> We don't have to refresh the whole data structure, but only the >> invalidated object(s). We have to have a good registry structure for the >> topology in order for this to be effective. >> > > A distributed map does this OOB. > >> >> >>> - If above happens, when serving multiple requests (with a high >>> frequency) on different instances of CC, the system might come to an >>> inconsistent state because the in memory data structures have not updated >>> properly. >>> >> >> Good point, thanks for pointing out. But the same problem will occur when >> using cluster messages to replicate the state, right? I guess we will have >> to resort to a distributed lock in either case to avoid consistencies. I >> remember Isuru was working on a hierarchical locking approach for the >> topology. Perhaps we can incorporate that for this scenario as well. >> > > We actually don't use cluster messages with a distributed map. However yes > in either approach we will need a distributed lock. Indeed, for topology we > should be able to change the existing locks to distributed ones if > clustering is enabled. > >> >> If you're going to use a distributed map, how do you plan to utilize that >> to distribute the topology data structure? I think replicating the complete >> topology object on change would be very expensive, wdyt? >> >> No, by design it will only send the modifications. > > Thanks > > > > -- > Imesh Gunaratne > > Technical Lead, WSO2 > Committer & PMC Member, Apache Stratos >
