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Priča asinkronim Spring servletima o
With an increasing number of connected devices on the Internet, handling of large number of concurrent requests in the applications becomes a priority. Traditional way of handling requests on a thread per request basis became an often encountered problem and a bottleneck for many high throughput services. Technology has therefore advanced to solve the problem by introducing asynchronous and non-blocking way of dealing with requests and processing. This session deals with Spring’s implementation based on asynchronous servlets for dealing with the mentioned issues.
Priča asinkronim Spring servletima o
- 1. Priča asinkronim Springservletima o Karlo Novak, SV Group d.o.o. karlo.novak@svgroup.hr
- 2. •Servleti •Asinkroni servleti,non-blocking IO •DefferedResult •Mjerenja •Non blocking API-i i alternative Sadržaj
- 3. •Thread per request •Blokiranje threadova •Čekanje na odgovor (baze podataka, vanjskog web servisa, pisanja na disk...) •Neefikasno, neskalabilno •C10k problem Klasični servleti
- 4. Asinkroni servleti •Omogućavajuasinkrone obrade •Čuvaju threadove iz web container poola –Threadovi se vraćaju u container kod IO-a, IO odrađuju threadovi iz drugih poolova •Preduvjet za korištenje non-blocking API-a
- 5. Non-blocking IO •Sve“akcije” koje ne blokiraju thread koji ih poziva •Rezultat obrađuju kroz Future, callback ili Observable (RxJava) •Štednja threadova = štednja memorije i procesora (smanjuje context switching) •Asinkrono + Non-blocking = Skalabilno
- 6. •Springova apstrakcija asinkronihservleta •Pojednostavljuje rad s async contextom •Zaprima objekt tipa “T” koji je konačni povratni rezultat Spring kontrolera •Rezultat se vraća korisniku tek kada se u DeferredResult pohrani povratni objekt DeferredResult<T> 1/3
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- 9. Mjerenja i usporedbe(1. runda) •Blocking servleti •Asinkroni servleti 200 threadova
- 10. Mjerenja i usporedbe(1. runda) •Asinkroni servleti 200 threadova •Blocking servleti
- 11. Mjerenja i usporedbe(2. runda) •Blocking servleti X threadova •Asinkroni servleti
- 12. Mjerenja i usporedbe(2. runda) •Blocking servleti X threadova •Asinkroni servleti
- 13. •NIO štedi threadove •Štednja CPU-a? –1000 threadova = ~10 000 ctxs/s •Štednja memorije? –1000 threadova = inicijalno ~30MB •NIO koristiti ako: –su threadovi usko grlo –broj threadova je iznimno velik i stvara značajnu razliku u potrošnji procesora i memorija (tisuće req/s) Zaključak mjerenja
- 14. Non-blocking API-i •SQL –PostgreSQL (https://github.com/alaisi/postgres.async) ? •HTTP klijenti –https://github.com/AsyncHttpClient/async-http-client •File IO –Netty, Java NIO •NOSQL –MongoDB (http://www.allanbank.com/mongodb-async- driver/index.html) –Infinispan (http://infinispan.org/docs/7.0.x/user_guide/user_guide.html#_asynchronous_api) –Cassandra(http://www.datastax.com/documentation/developer/java- driver/1.0/java-driver/asynchronous_t.html)
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- 16. Asinkroni servleti susuper za određene use caseove, ali ne rješavaju magično sve probleme s performansama i ne poboljšavaju performanse sustava “sami od sebe” Zaključak zaključka
- 17. A sad vi... karlo.novak@svgroup.hr