Sounds good! Thanks for the detailed info. Can you please provide the updated API in the ticket?
On Thu, Aug 17, 2017 at 12:41 AM, Denis Mekhanikov <[email protected]> wrote: > > Can we add an "allOrNone" flag to the deployment method? > > Sounds good, I think we can. > > > However, hot do you ensure atomicity here? > > We can guarantee that if some of configurations are invalid, or a > transaction, that writes configuration to the internal cache, fails, then > no services will be deployed. > > Currently we don't track failures on the server side and services are > considered successfully deployed once their configurations are written to > the cache. So, it's not possible that all configurations are valid, but > only a part of the services fail to deploy. If we change this behavior and > start tracking failures during deployment and initialization on the server, > then we could automatically cancel services that are already deployed in a > batch. > > чт, 17 авг. 2017 г. в 8:34, Dmitriy Setrakyan <[email protected]>: > > > On Wed, Aug 16, 2017 at 8:17 AM, Denis Mekhanikov <[email protected] > > > > wrote: > > > > > I've had a few off-line conversations with other Igniters regarding > this > > > question and almost all of them think that services should be deployed > > with > > > "all-or-none" failing policy. > > > We have a similar functionality for caches: Ignite#createCaches method > > > don't allow partial deployments, and I think, we should also stick to > > this > > > principle for services. > > > > > > > Can we add an "allOrNone" flag to the deployment method? If true, then > all > > services will have to either be deployed or failed. However, hot do you > > ensure atomicity here? If you are deploying 10 services, and only 1 > fails, > > what do you do with the other 9, given that they have already been > deployed > > and may have started serving API requests? > > > > > > > > > > Another question that I'd like to discuss here is that currently > > > IgniteServices#deployAsync method may fail with an exception instead of > > > returning a future. Shouldn't we change this behavior to make async > > > operations always return a future whose get() method would throw an > > > exception? > > > > > > > Makes sense to me. I think throwing exception from async method is plain > > wrong. > > > > > > > > вт, 15 авг. 2017 г. в 11:42, Dmitriy Setrakyan <[email protected] > >: > > > > > > > Denis, > > > > > > > > I don't think we need a king deployment result. > > > > > > > > The "deployAllAsync" method should never throw an exception, it > should > > > > always return the future. However, the IgniteFuture.get(...) method > > does > > > > throw an exception, and in this exception you should provide the info > > > about > > > > the failures. > > > > > > > > D. > > > > > > > > On Tue, Aug 15, 2017 at 1:31 AM, Denis Mekhanikov < > > [email protected] > > > > > > > > wrote: > > > > > > > > > Dmitriy, thank you for your reply! > > > > > > > > > > I see a possibility of a bad scenario here. If we use > deployAllAsync > > > > method > > > > > and it throws an exception, then the constructed future won't be > > > returned > > > > > and we won't have a way to wait for the rest of the services to > > deploy. > > > > > Maybe we should return some king of deployment result, containing a > > > > future > > > > > along with a collection of failed services, instead of throwing an > > > > > exception? > > > > > > > > > > пн, 14 авг. 2017 г. в 18:03, Dmitriy Setrakyan < > > [email protected] > > > >: > > > > > > > > > > > Hi Denis, I agree, we should have an API for batch service > > > deployment. > > > > My > > > > > > comments are inline... > > > > > > > > > > > > On Mon, Aug 14, 2017 at 2:22 AM, Denis Mekhanikov < > > > > [email protected] > > > > > > > > > > > > wrote: > > > > > > > > > > > > > Hi Igniters! > > > > > > > > > > > > > > Currently Ignite doesn't have support for batch service > > deployment, > > > > but > > > > > > it > > > > > > > may be a very useful feature in case of a big number of nodes > in > > a > > > > > > cluster > > > > > > > and services to be deployed. Each deployment includes write > into > > an > > > > > > > internal transactional cache, which is the longest part of the > > > > > procedure. > > > > > > > > > > > > > > I propose to optimize it by performing multiple writes in a > > single > > > > > > > transaction. It implies an introduction of a few new methods in > > > > > > > IgniteServices interface. > > > > > > > I am thinking about the following signatures: > > > > > > > > > > > > > > void deployAll(Iterable<ServiceConfiguration> cfgs) throws > > > > > > > IgniteException; > > > > > > > IgniteFuture<Void> > > deployAllAsync(Iterable<ServiceConfiguration> > > > > > > > cfgs) throws IgniteException; > > > > > > > > > > > > > > I'd like to know your opinion on the following questions: > > > > > > > > > > > > > > - Do you agree with the proposed signatures? > > > > > > > > > > > > > > > > > > > Yes, but Iterable should be changed to Collection to be > consistent > > > with > > > > > > other similar APIs in Ignite. > > > > > > > > > > > > > > > > > > > - What should happen in case of a failure (some of the > > > > > configurations > > > > > > > don't pass validation, or a service with specified name but > > > > > different > > > > > > > configuration already exists)? Should partial deployments be > > > > > performed > > > > > > > in > > > > > > > case when some of them fail? > > > > > > > > > > > > > > > > > > > Yes, we should allow partial deployment. The exception thrown > > should > > > > > have a > > > > > > collection of services that have failed deployment. It looks like > > you > > > > > will > > > > > > need to create ServiceDeploymentException (extends > IgniteException) > > > to > > > > > > handle this case (in which case, you have to make sure that other > > > > deploy > > > > > > methods also throw it). > > > > > > > > > > > > > > > > > > > > > > > > > > Regarding the second question I think that we shouldn't deploy > > any > > > > > > services > > > > > > > in a batch if we encounter any problems with some of them. > > > > > > > > > > > > > > Also cancelAll method may be optimized in a similar way, but no > > > > > interface > > > > > > > changes are needed there. > > > > > > > > > > > > > > Ticket: https://issues.apache.org/jira/browse/IGNITE-5145 > > > > > > > > > > > > > > -- > > > > > > > Cheers, > > > > > > > Denis Mekhanikov > > > > > > > > > > > > > > > > > > > > > > > > > > > >
