I would like to test the event store's performance and throughput in an event-sourced application. The application is a simple bank account (source: https://eventsourcing.readthedocs.io/en/stable/topics/examples/bank-accounts.html) where the "Account" is an aggregate that emits an event "Opened" whenever a new account aggregate is created. My objective is to plug different event stores into the application and test its performance and throughput. I would like to have a graph similar to this:
I have an RDS Postgres running which I would be testing first. There are other database candidates for the event store that I am planning to test and all will be running on AWS. In the graph, the event rate is the aggregate creation rate where each event is emitted when a new aggregate is created and every new command for aggregate creation is executed only after the acknowledgment.
P.S.: In my quest, I have come across many tools like Jmeter and Gatling but I am not able to think of how to perform such tests with these tools.
What are you trying to test here? Performance of the RDS? Or performance of sample code from eventsource package documentation? Well-behaved load test must simulate real life system under test usage so if your "application" will have the frontend like web page or API or it will be used by the upstream system somehow you could implement this contract first and then choose the appropriate load testing tool which can simulate the real life usage of this contract.
If your "application" is just a piece of Python code and it will always be like this I don't think you will be able to use JMeter or Gatling for calling the application, take a look at Locust which is a Python-based load testing framework providing the possibility to call the functions of your "application"
See What Is Locust Load Testing? article for more details.
Related
For example, if i have main application (backend) and some microservice, e.g for image cropping.
User loads an image, making request to backend, backend using rabbitmq posts new task in the queue, then image cropping service pickup a task, completes it and i need somehow notify backend.
What is options for this? I need another microservice for such notifications?
so... there are reaaaaaaly many ways to do that.
On the high level, what you want to achieve is to produce an event that 1 or more services can react to. Now depending on what you have available, you can produce the event in a number of different ways.
if you want to be completely platform independent, you can use Apache Kafka. It's a popular service specifically for what we need -> publishing events and processing them at mass-scale. Kafka can be clustered, partitioned, have multiple parallel consumers of the same type (like multiple instances of your main backend service) or different types (3 different microservices that happen to be interested in a specific event). This bad boy just has it all and is famous for that. You can set up a cluster yourself or use one that comes out-of-the-box with some of the cloud platforms (like AWS for instance), but this might be more expensive and difficult to use compared to some cloud-specific fully-managed solutions.
if you're running your stuff on the google cloud, you can make it easier and cheaper by using the PubSub service. PubSub is a fully managed service that is scaled out-of-the-box (welcome to the cloud! you don't need to scale or cluster anything by yourself!).
if you're running on AWS, you can use SNS, or a more recent alternative - EventBridge (kinda like SNS, but booooooy what can it not do?). Yeah... I would recommend EventBridge. It can just do more... with the target filtering rules, payload transformations, it can automatically trigger more things...
Azure... ehm... Event Hub... but I haven't worked with this one yet... I'm not much of an Azurer... because you know... nobody uses azure for this kind of stuff...
I am writing payroll management web application in nodejs for my organisation. In many cases application shall involve cpu intensive mathematical calculation for calculating the figures and that too with many users trying to do this simulatenously.
If i plainly write the logic (setting aside the fact that i already did my best from algorithm and data structure point of view to contain the complexity) it will run synchronously blocking the event loop and make request, response slow.
How to resolve this scenario? What are the possible options to do this asynchronously? I also want to mention that this calculation stuff can be let to run in the background and later i can choose to tell user via notification about the status. I have searched for the solution all over this places and i found some solutions but only in theory & i haven't tested them all by implementing. Mentioning below:
Clustering the node server
Use worker threads
Use an alternate server and do some load balancing.
Use a message queue and couple it with worker thread to do backgound tasks.
Can someone suggest me some tried and battle tested advice on this scenario? and also some tutorial links associated with that.
You might wanna try web workers,easy to use and documented.
https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Using_web_workers
I am trying to figure out how (or even if) I can replace the API calls made by my app when running a Webdriver test to return stubbed output. The app uses a lot of components that are completely dependent on a time frame or 3rd party info that will not be consistent or reliable for testing. Currently I have no way to test these elements without using 'run this test if...' as an approach which is far from ideal.
My tests are written in C#.
I have found a Javascript library called xhr-mock which seems to kind of do what I want but I can't use that with my current testing solution.
The correct answer to this question may be 'that's not possible' which would be annoying but, after a whole day reading irrelevant articles on Google I fear that may be the outcome.
WebDriver tests are End to End, Black Box, User Interface tests.
If your page depends on an external gateway,
you will have a service and models to wrap that gateway for use throughout your system,
and you will likely already be referencing your models in your tests.
Given the gateway is time dependent, you should use the service consumed by your api layer in your tests as-well, and simply check that the information returned by the gateway at any time is displayed on the as page as you would expect it to be. You'll have unit tests to check the responses model correctly.
As you fear, the obligatory 'this may not be possible': Given the level of change your are subject to from your gateway, you may need to reduce your accuracy or introduce some form of refresh in your tests, as the two calls will arrive slightly apart.
You'll likely have a mock or stub api in order to develop the design, given the unpredictable gateway. It would then be up to you if you used the real or fake gateway for tests in any given environment. These tests shouldn't be run on production, so I would use a fake gateway for a ci-test environment and the real gateway for a manual-test environment, where BBT failures don't impact your release pipeline.
Context
I want to develop an automated script for broker (IIB9/10) resource monitoring, capturing information about broker running status, message flows deployed, jvm usage, number of threads running, etc.
The initial thought is to have a report generated using scripts and then displayed over a browser.
Question
Can this be entirely done using only Ant scripts (i am not sure as have not explored iterative processing in Ant in detail) or a combination of Ant and batch/shell scripts is the best bet?
I know Web user interface in IIB10 does most of it but i want to add some features.
I suggest you to take a look at message flow statistics and accounting:
http://www-01.ibm.com/support/knowledgecenter/SSMKHH_9.0.0/com.ibm.etools.mft.doc/ac19100_.htm?lang=en
This is a feature of IIB by which it is capable of emitting resource statistics. The statistics are published to a topic in a well defined XML format. I would try solving your requirement by writing an application to read these messages and use the data in them to generate your graphs or other reports.
There is a support pack, IS03 which can give you an idea of such an application.
This will not cover everything you mentioned, for example monitoring what flows are deployed cannot be achieved like this, but it gives a comprehensive view of the load and performance of your applications:
http://www-01.ibm.com/support/knowledgecenter/SSMKHH_9.0.0/com.ibm.etools.mft.doc/bj10440_.htm?lang=en
And there is a resource statistics feature as well for monitoring resources used by your applications:
http://www-01.ibm.com/support/knowledgecenter/SSMKHH_9.0.0/com.ibm.etools.mft.doc/bj43310_.htm?lang=en
To get everything you will need a variety of tools I think. You can use Resource Stats and Accounting / Stats as suggested by Attila to get JVM and thread usage. The Broker publishes updates to a topic so you can create a simple subscriber to grab that info.
For deploy related info, stop / start state and so forth I would be looking at building simple Integration API or REST API applications to call from ant.
You can find documentation for these API's here:
http://www-01.ibm.com/support/knowledgecenter/SSMKHH_10.0.0/com.ibm.etools.mft.doc/be43410_.htm?lang=en
and here:
http://www-01.ibm.com/support/knowledgecenter/api/content/nl/en-us/SSMKHH_10.0.0/com.ibm.etools.mft.restapi.doc/index.html
I have the following setup
Customer access -> Web application -> Database
A Server application (console based) for each customer running in the Server continuously that downloads data from various locations and update database
So if i am having 100 customers, i will need to run 100 console applications in the server.
If there is any problem/crash with one server application(because of specific kind of data i am downloading), i will be able to fix it by restarting or patching.
I took this approach as i initially thought it is easy to maintain. But feeling not anymore. I am sure there are better tools available outside to manage this kind of scenarios. If you know any please let me know. I should be able start/restart/patch/monitor server usage/check for crash on the server application through some nice GUI.
Or may be there is a way to write one multi-threaded application to serve all customers instead of one for each. And there may be a way to shutdown/restart the any customer's thread.
Thanks
The right way is to use a threaded application that can set your tenant context for the process that needs to be done for that thread.
This way, we have 1 app for all customers and van make use of application events and mailers to notify on case of any error.
An audit table with track of the various data processing status can help in a GUI to be built for tracking the progress on a tenant basis.
HTH