Pavel, I might be missing something - could you please elaborate a little more?
When I say "sync on top of async", I basically mean that (for example) 'insert(..)' is equivalent to 'insertAsync(..).join()'. In my understanding, it only blocks the user's thread. Am I wrong? Or you have a different implementation in mind? -Val On Wed, Sep 8, 2021 at 12:50 AM Pavel Tupitsyn <ptupit...@apache.org> wrote: > Val, > > Agree with your points. > > > > async API should be primary > > It should be noted that all our APIs are inherently async, > because thin client is implemented asynchronously. > > > > with the sync version build on top > > We should document somehow that sync APIs are based on async ones, > because this may be dangerous in some use cases. > > For example, as a user, I may have a thread pool of 4 threads for > Ignite-related usage, that is also set as asyncContinuationExecutor [1]. > Now if I run a lot of concurrent Ignite requests using sync API, all 4 > threads will end up blocked on CompletableFutures. > When one of the operations completes, we enqueue the completion to that > same thread pool, but all threads are blocked on sync APIs, resulting in a > deadlock. > > This can be prevented by using a different asyncContinuationExecutor, but > sync API users won't be usually aware of this. > > > [1] https://issues.apache.org/jira/browse/IGNITE-15359 > > On Wed, Sep 8, 2021 at 10:04 AM Courtney Robinson < > courtney.robin...@hypi.io> > wrote: > > > Hi Val, > > > > I'd highly support an async first API based on CompletionStage > > < > > > https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/CompletionStage.html > > > > > or > > its subtypes like CompletableFuture. > > In Ignite 2 we've written a wrapper library around IgniteFuture to > provide > > CompletionStage instead because many of the newer libs we use support > this. > > If Ignite 3 went this way it'd remove a lot of boiler plate/wrapper that > we > > wrote to get what you're suggesting here. > > > > Regards, > > Courtney Robinson > > Founder and CEO, Hypi > > Tel: ++44 208 123 2413 (GMT+0) <https://hypi.io> > > > > <https://hypi.io> > > https://hypi.io > > > > > > On Wed, Sep 8, 2021 at 12:44 AM Valentin Kulichenko < > > valentin.kuliche...@gmail.com> wrote: > > > > > Igniters, > > > > > > I would like to gather some opinions on whether we want to focus on > sync > > vs > > > async APIs in Ignite 3. > > > > > > Here are some initial considerations that I have: > > > 1. Ignite 2.x is essentially "sync first". Async APIs exist, but they > use > > > non-standard IgniteFuture and provide counterintuitive guarantees. In > my > > > experience, they significantly lack usability, and because of that are > > > rarely used. > > > 2. In general, however, async execution becomes more and more > prominent. > > > Something we can't ignore if we want to create a modern framework. > > > 3. Still, async support in Java is very limited (especially if compared > > to > > > other languages, like C# for example). > > > > > > My current position is the following (happy to discuss): > > > 1. We should pay more attention to async APIs. As a general rule, async > > API > > > should be primary, with the sync version build on top. > > > 2. In languages with proper async support (async-await, etc.), we can > > skip > > > sync API altogether. As an example of this, you can look at the first > > > version of the .NET client [1]. It exposes only async methods, and it > > > doesn't look like sync counterparts are really needed. > > > 3. In Java (as well as other languages where applicable), we will add > > sync > > > APIs that simply delegate to async APIs. This will help users to avoid > > > CompletableFuture if they don't want to use it. > > > > > > [1] https://github.com/apache/ignite-3/pull/306 > > > > > > Please share your thoughts. > > > > > > -Val > > > > > >
