Hi Rafał, First, thanks for the reply. If you look towards the end of my post I actually tried that with AWS. I suspected there might be an issue with using a single machine so created a couple of instances on AWS. I found the similar degradation.
With my application running on one t2.small instance I got about 120 requests per second. I brought up another t2.small instance and the requests per second dropped to about 80. I brought up a third instance and the performance increased this time to about 100 requests per second. I suppose my main question here is should I be seeing an appreciable increase in performance when using Akka clustering and add cluster nodes? i.e. Is the problem related to Akka clustering or is it more likely to be an issue (bottleneck?) somewhere in my application? Thanks Robert On Wednesday, May 13, 2015 at 3:46:14 PM UTC+1, Robert O'Regan wrote: > > I'm building a RESTful API using Akka and Spray. I'm using the Typesafe > Akka Cluster Sample project... > > (http://www.typesafe.com/activator/template/akka-sample-cluster-scala) > > as a reference. I have a cluster which uses a pool of routees and cluster > aware routing. The interface to the API is through a spray frontend which > creates an actor (ClusterClient) that acts as a frontend to the cluster and > monitors cluster activity (new nodes, downed nodes etc...). When a request > comes in to a spray route I delegate the work to a Cluster backend worker > via the cluster aware router. > > My hope/goal here is that I can increase performance in the system by > adding more back-end worker nodes and routees as needed. I may also add > more frontend (spray) nodes that will be accessed via a Load Balancer. I'm > trying to build something performant and scalable. > > This all works fine. The worker actors at the moment just return a string > for testing. > > Before I go any further I wanted to get an idea of current cluster > performance by stress testing the application. So I am using apache bench > to do some quick tests. > > All the testing is being done on my local development machine (QuadCore > Macbook Pro with 16gb RAM). The application is running on spray-can. The > frontend (spray) and backend nodes are being kicked off on seperate JVM's > on the same machine by using different ports. > > The strange thing is performance seems to degrade when I add more backend > nodes to the cluster. Here are my tests and results. I ran each test about > 10 times to get better average... > > One Backend Node > > ab -l -n 1000 -c 100 http://localhost:3050/api > > Requests per second [#/sec] (mean): 4708.25, 5086.11, 4341.52, 5850.76, > 4403.33, 5046.78, 4151.84, 5686.24, 3399.38, 4466.26, 3755.98, 5619.18, > 5187.96 > Average: 4745 requests per second > > Two Backend Nodes > > ab -l -n 1000 -c 100 http://localhost:3050/api > > Requests per second [#/sec] (mean): 3381.75, 4108.51, 2969.41, 3732.29, > 3804.48, 3644.12, 2516.05, 2968.17, 3308.01, 3378.69, 4049.71, 3738.21, > 4068.84 > Average: 3512 requests per second > > Three Backend Nodes > > ab -l -n 1000 -c 100 http://localhost:3050/api > > Requests per second [#/sec] (mean): 2756.49, 2516.77, 2535.34, 2464.37, > 2887.51, 2421.98, 2794.03, 2633.36, 2735.74, 3021.81, 2612.39, 3052.53, > 3714.88 > Average: 2780 requests per second > > Is this expected? i.e. Am I wrong in thinking that I should be getting > more performance by adding more backend/worker nodes? Based on the figures > above, the more nodes I add to the cluster the worse the performance will > become. > > I also ran the same tests on AWS using a couple of t2.small instances. On > both instances I deployed my application and kicked off two "backend" > cluster nodes. I then started my frontend spray node on one of the > instances and used apache bench to test the cluster. > > Again I get about 30% less performance from the cluster when I have two > backend nodes compared to one. So the problem does not seem to be related > to running the test on a single development machine. > > Has anyone any ideas? Am I using Akka's clustering capabilities > incorrectly? > > Thanks > -- >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>>>>>> Check the FAQ: >>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups "Akka User List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
