Re: COMMERCIAL:Re: [Question] Distributed Load Testing with Mesos and Gatling
On 07/02/2015 12:10 PM, Carlos Torres wrote: From: CCAAT cc...@tampabay.rr.com Sent: Thursday, July 2, 2015 12:00 PM To: user@mesos.apache.org Cc: cc...@tampabay.rr.com Subject: COMMERCIAL:Re: [Question] Distributed Load Testing with Mesos and Gatling On 07/01/2015 01:17 PM, Carlos Torres wrote: Hi all, In the past weeks, I've been thinking in leveraging Mesos to schedule distributed load tests. An excellent idea. One problem, at least for me, with this approach is that the load testing tool needs to coordinate the distributed scenario, and combine the data, if it doesn't, then the load clients will trigger at different times, and then later an aggregation step of the data would be handled by the user, or some external batch job, or script. This is not a problem for load generators like Tsung, or Locust, but could be a little more complicated for Gatling, since they already provide a distributed model, and coordinate the distributed tasks, and Gatling does not. To me, the approach the Kubernetes team suggests is really a hack using the 'Replication Controller' to spawn multiple replicas, which could be easily achieved using the same approach with Marathon (or Kubernetes on Mesos). I was thinking of building a Mesos framework, that would take the input, or load simulation file, and would schedule jobs across the cluster (perhaps with dedicated resources too minimize variance) using Gatling. A Mesos framework will be able to provide a UI/API to take the input jobs, and report status of multiple jobs. It can also provide a way to sync/orchestrate the simulation, and finally provide a way to aggregate the simulation data in one place, and serve the generated HTML report. Boiled down to its primitive parts, it would spin multiple Gatling (java) processes across the cluster, use something like a barrier (not sure what to use here) to wait for all processes to be ready to execute, and finally copy, and rename the generated simulations logs from each Gatling process to one node/place, that is finally aggregated and compiled to HTML report by a single Gatling process. First of all, is there anything in the Mesos community that does this already? If not, do you think this is feasible to accomplish with a Mesos framework, and would you recommend to go with this approach? Does Mesos offers a barrier-like features to coordinate jobs, and can I somehow move files to a single node to be processed? This all sounds workable, but, I do not have all the experiences necessary to qualify your ideas. What I would suggest is a solution that lends itself to testing similarly configured cloud/cluster offerings, so we the cloud/cluster community has a way to test and evaluate new releases, substitute component codes, forks and even competitive offerings. A ubiquitous and robust testing semantic based on your ideas does seem to be an overwhelmingly positive idea, imho. As such some organizational structures to allow results to be maintained and quickly compared to other 'test-runs' would greatly encourage usage. Hopefully 'Gatling' and such have many, if not most of the features needed to automate the evaluation of results. Finally, I've never written a non-trivial Mesos framework, how should I go about, or find more documentation, to get started? I'm looking for best practices, pitfalls, etc. Thank you for your time, Carlos hth, James Thanks for your feedback. I like your idea about having the ability to swap out the different components (e.g. load generators) and perhaps even providing an abstraction on the charting, and data reporting mechanism. I'll probably start with the simplest way possible, though, having the framework deploy Gatling across the cluster, in a scale-out fashion, and retrieve each instance results. Once I got that working then I'll start experimenting with abstracting out certain functionality. I know Twitter has a distributed load generator, called Iago, that apparently works in Mesos, it'd be awesome, if any of its contributors chime in, and share what things worked great, good, and not so good. The few things I'm concern in terms of implementing such a framework in Mesos is: * Noisy neighbors, or resource isolation. - Rationale: It can introduce noise to the results if load generator competes for shared resources (e.g. network) with others tasks. * Coordination of execution - Rationale: Need the ability to control execution of groups of related tasks. User A submits simulation that might create 5 load clients (tasks?), right after that, User B submits a different simulation that creates 10 load clients. Ideally, all of User A load clients should be on independent nodes, and should not share the same slaves with User B load clients, if not enough slaves are available on the cluster, then User B's simulation queues, until slaves are available. There might be enough resources
Re: COMMERCIAL:Re: [Question] Distributed Load Testing with Mesos and Gatling
Yes, I agree, I think starting out with the scale-out approach, while naive, it will be a good starting point. I actually have this automated with Jenkins, and a bunch of dedicated slaves, using the Workflow plugin, it works kind of OK since I can't really control their execution. If you are interested, here's my workflow script for Jenkins: https://github.com/meteorfox/gatling-workflow/blob/master/gatling_flow.groovy -- Carlos From: Joao Ribeiro jonnyb...@gmail.com Sent: Thursday, July 2, 2015 11:33 AM To: user@mesos.apache.org Subject: COMMERCIAL:Re: [Question] Distributed Load Testing with Mesos and Gatling This sounds like a really cool project. I am still a very green user of mesos and never used gatling at all but a quick search took me to http://gatling.io/docs/2.1.6/cookbook/scaling_out.html With this it sound’t be took difficult to create a master/slave or scheduler/executors approach where you would have the master launch several slaves to do the work, wait for it to finish, collect logs and generate the report. For better synchronisation you could make the slaves register to zookeeper while master waits for all slaves to be up and trigger a “start test” command on all slaves simultaneously. You then could easily time out if it takes too long to get all slaves up or use other more fault tolerant strategies. i.e.: run slaves that you got; bump each slave that is up with more load to try to make up for missing slaves; It might be a naive approach but would be a starting point in my opinion. On 02 Jul 2015, at 18:00, CCAAT cc...@tampabay.rr.commailto:cc...@tampabay.rr.com wrote: On 07/01/2015 01:17 PM, Carlos Torres wrote: Hi all, In the past weeks, I've been thinking in leveraging Mesos to schedule distributed load tests. An excellent idea. One problem, at least for me, with this approach is that the load testing tool needs to coordinate the distributed scenario, and combine the data, if it doesn't, then the load clients will trigger at different times, and then later an aggregation step of the data would be handled by the user, or some external batch job, or script. This is not a problem for load generators like Tsung, or Locust, but could be a little more complicated for Gatling, since they already provide a distributed model, and coordinate the distributed tasks, and Gatling does not. To me, the approach the Kubernetes team suggests is really a hack using the 'Replication Controller' to spawn multiple replicas, which could be easily achieved using the same approach with Marathon (or Kubernetes on Mesos). I was thinking of building a Mesos framework, that would take the input, or load simulation file, and would schedule jobs across the cluster (perhaps with dedicated resources too minimize variance) using Gatling. A Mesos framework will be able to provide a UI/API to take the input jobs, and report status of multiple jobs. It can also provide a way to sync/orchestrate the simulation, and finally provide a way to aggregate the simulation data in one place, and serve the generated HTML report. Boiled down to its primitive parts, it would spin multiple Gatling (java) processes across the cluster, use something like a barrier (not sure what to use here) to wait for all processes to be ready to execute, and finally copy, and rename the generated simulations logs from each Gatling process to one node/place, that is finally aggregated and compiled to HTML report by a single Gatling process. First of all, is there anything in the Mesos community that does this already? If not, do you think this is feasible to accomplish with a Mesos framework, and would you recommend to go with this approach? Does Mesos offers a barrier-like features to coordinate jobs, and can I somehow move files to a single node to be processed? This all sounds workable, but, I do not have all the experiences necessary to qualify your ideas. What I would suggest is a solution that lends itself to testing similarly configured cloud/cluster offerings, so we the cloud/cluster community has a way to test and evaluate new releases, substitute component codes, forks and even competitive offerings. A ubiquitous and robust testing semantic based on your ideas does seem to be an overwhelmingly positive idea, imho. As such some organizational structures to allow results to be maintained and quickly compared to other 'test-runs' would greatly encourage usage. Hopefully 'Gatling' and such have many, if not most of the features needed to automate the evaluation of results. Finally, I've never written a non-trivial Mesos framework, how should I go about, or find more documentation, to get started? I'm looking for best practices, pitfalls, etc. Thank you for your time, Carlos hth, James
