Another +1 for the true asynchronous approach. I remember a while ago one of the Ignite users raised a similar question regarding the *async method being blocked on establishing a TCP connection.
As far as deadlocks go, I have a counter-example. Currently, we check the thread-local chain only for a single cache, so if I run the following code: cache1.getAsync(k1); cache2.getAsync(k2); then the deadlock is still possible, and I did not see a single user complaining about unexpected deadlocks. Rather than implementing this cross-cache chain (which would probably add another overhead), I would make it consistent and allow operations to be run in parallel. There are many use-cases when having true async operations dramatically improve performance. Consider, for example, a streaming example when keys are being pushed by a client to a cluster. Currently, to run effective processing, the user will have to use a data streamer with custom keys receiver which may be a huge usability downside. Async operations can utilize the cluster resources very efficiently. Finally, if we want to be on the safe side, we can keep the operation chain inside a transaction. I see absolutely no point in maintaining this chain outside of transactions. --AG 2018-05-14 16:01 GMT+03:00 Dmitriy Govorukhin <dmitriy.govoruk...@gmail.com> : > Andrey, > > Do you prefer change behavior at runtime? > I guess will be better have different methods for getting cache instance > with fair and not fair sync. > > On Mon, May 14, 2018 at 3:39 PM, Andrey Gura <ag...@apache.org> wrote: > > > +1 for fair async operations. > > > > But I don't like idea use withFairSync() method. We added xxxAsync() > > methods recently and withAsync() is deprecated. > > > > I think we should just make methods are async in nature and provide > > ability of switching to the old behaviour using flag or property. > > > > On Fri, May 11, 2018 at 11:00 PM, Dmitriy Setrakyan > > <dsetrak...@apache.org> wrote: > > > Vladimir, > > > > > > In general I agree, but I do get greatly *close-minded* (pun intended) > > > whenever users' code that worked for the past several years all of a > > sudden > > > gets deadlocked after an upgrade. Making this feature optional is even > > > worse and more confusing. In this case the best action is no action at > > all. > > > > > > BTW, would be interesting to find out how Oracle async driver behaves > in > > > this case. > > > > > > D. > > > > > > > > > > > > > > > > > > On Fri, May 11, 2018 at 8:29 PM, Vladimir Ozerov <voze...@gridgain.com > > > > > wrote: > > > > > >> Guys, > > >> > > >> To build a great product we should be open minded and look to the > > future, > > >> not to the past. > > >> > > >> Dima raised very valid point - why async is not async? Current > > programming > > >> culture and demanding performance requirements pushes users towards > > >> reactive-style programming. I do not want my thread to ever be > blocked. > > >> Instead, I want to send a number of concurrent commands and optionally > > >> subscribe to final result. So trully async API makes total sense to > me. > > >> > > >> But personally, my primary interest in this area is SQL. Oracle is > > >> preparing new async driver. ADBA - async database access. It was > > presented > > >> on recent JavaOne [1]. It is under active development right now - juse > > >> weave through the mailing list [2]. Some prototypes are already there > > [3]. > > >> PostgreSQL community even started adopted it [4]! > > >> > > >> I am not pushing for immediate actions, but at least we should > > understand > > >> which way the wind is blowing. As a mid-term goals I would propose to > > >> finally remove thread ID from our PESSIMISTIC transactions to allow > for > > >> suspend/resume in different threads. And as a next step I would think > on > > >> adopting async cache and SQL APIs. > > >> > > >> Vladimir. > > >> > > >> [1] > > >> http://www.oracle.com/technetwork/database/ > > application-development/jdbc/ > > >> con1491-3961036.pdf > > >> [2] http://mail.openjdk.java.net/pipermail/jdbc-spec-discuss/ > > >> [3] https://github.com/oracle/oracle-db-examples/tree/master/java/AoJ > > >> [4] https://github.com/pgjdbc/pgjdbc/issues/978 > > >> > > >> On Fri, May 11, 2018 at 9:48 PM, Dmitriy Setrakyan < > > dsetrak...@apache.org> > > >> wrote: > > >> > > >> > On Fri, May 11, 2018 at 7:46 PM, Dmitriy Govorukhin < > > >> > dmitriy.govoruk...@gmail.com> wrote: > > >> > > > >> > > I will edit IGNITE-8475, and remove all part that belong to the > > public > > >> > api. > > >> > > Is it acceptable for you? > > >> > > > > >> > > > >> > Everything is acceptable, as long as the public API is safe :) > > >> > > > >> > > >
