I am looking to find out the response times that takes for my nodejs application with (lets say) when 1000 users uses it simultaneously. I believe this is called stress testing. How Can I acheive this ?
I am new to testing area and yet to acquire knowledge on tools that will be used.
Edit: I need to know how to have virtual users for the application.
In order to understand the response times for an application under load, you need two components:
A load driver
There's a number of available tools that will simulate users making HTTP requests. A simple open source option is (Apache JMeter. The following page in the documentation shows you how to create a web test plan, including adding virtual users:
http://jmeter.apache.org/usermanual/build-web-test-plan.html
A performance monitoring tool
In order to understand how your application is performing under the load, and measure application responsiveness, you need a performance monitoring tool. One set of options is to track the performance of 'http' monitoring events using Node Application Metrics, either using the API directly, or using an open source monitoring stack like Elasticsearch/Kibana using the ELK Connector for Node Application Metrics. There's a getting started guide to monitoring Node.js application performance with Elasticsearch/Kibana here:
https://developer.ibm.com/open/2015/09/07/using-elasticsearch-and-kibana-with-node-application-metrics/
Related
For years I always use IIS Looging always active on my sites. I currently use Windows Server 2008 R2 and Windows Server 2012. The official information I follow is this:
https://learn.microsoft.com/en-us/windows/desktop/http/iis-logging
I have looked for official information from Microsoft asking if it is recommended to always use this feature active or it is better to enable it only when you want to trace a problem.
Do you know if there is any official information?
Is there any study that says how much is the degradation of the
response times or general speed of the site to be active?
If I use an architecture with a Load Balancer F5 or A10 or Apache
that connect to my nodes, is it recommended to use Logging in the
Load Balancer always if it is deactivated in the nodes?
thanks!
IIS logging is processed on separate threads from the gateway services and app pools. Which means that it will not degrade performance.
Don't just take my word for it. If you want to confirm this, you can use a capacity testing tool (not recommended on your prod server, of course). Test your capacity with logging turned-on and logging turned-off. You will see that they are comparable.
We are having issues with an Azure Application Service. One of our webservices (MVC) caches data from the database at startup (Application_Start) - this takes approximately 3 minutes. Until this is ready we can't handle requests.
This is known so we set it 'always on' and will aim to only restart it during off-peak times if necessary.
However, we expect heavy load to the server next month, and in our testing of the auto-scaling, we have found that when it adds additional instances, each of these instances goes through the same startup delay - but the traffic is split between the current running instance and the new one that's warming up so e.g. half of the requests start failing for that 3 minute period.
How can we configure Azure to delay using the new instance until it is ready? (or should we be using e.g. AWS instead?).
Some of the documentation points to using a custom Load Balancer Probe however it mainly talks about VM's whereas we are using PAAS.
Do try to reduce the data you need to load on app_start and try to lazy load data into Cache on first request. Some times even after doing all of this we do end up with large sets of data that is necessary on start.
There are two ways we can approach this.
One, assuming you are using in-memory caching and every instance of the app needs to hydrate its in-memory cache on App_Start. Try to use a external cache provider like Azure Cache for Redis, your new instance can just point to this external cache without having to reload the data.
Two, you can depend on Application Initialization Module which was introduced in IIS 7.5 (installed on Azure App Services' IIS). To use this feature, you need to add applicationInitialization section under web.server section of web.config. This will help you not make the instance available until the warm-up process is completed. More info on how to use ApplicationInitialization is available in this blog post
The best case would be to use the combination of both, applicationInitialization will point at a page in your application which checks if the external cache is available and hydrated, if yes, complete, else hydrate the external cache.
You can do this in Azure with other resource type than classic VM like an App Service. App Services scale up and down with instances that share the same memory pool and thread pool.
There is a lot of good information, in the link https://www.jan-v.nl/post/warming-up-your-app-service that was included in one of the comments.
Based on that information the functionality that you require is not available in the free tier.
I would approach the problem differently. Why does it take 3 mins to load the data from the database? Since it is only loaded on start it should be data that does not change often.
Could you:
Optimise the reading of data from the database?
Reduce the amount of data you read from the database?
Export the data to a file, and read it from a file?
My recommendation would be to use an Azure Load Balancer with a health probe
I work with an ARM based embedded system with a Linux kernel and a fairly large filesystem image(~1GB). The kernel and filesystem are under my control, so I can add modules and re-build if necessary.
The system has Node.js and on top of this Node-Red for an IOT application. I want to leverage the simple server capability of Node-Red to serve a web page showing graphically the system performance statistics.
I am considering building collectd for the target system and using it to write performance data to the filesystem. Then, I will use Node-Red/Node.js to present this information as a web page. This approach seems straightforward enough to be doable.
My question is: is there an alternative, established way of implementing such a remote system performance viewer? Or can anyone suggest a lightweight performance monitor and a method of displaying the statistics graphically on a web page?
I started node-spm for that logging to Sematext Logsene and writing custom metrics to SPM. I collected also process and OS metrics. It's in an early stage and I will do in the next few weeks more on that.
I am relatively new to Azure. I have a website that has been running for a couple of months with not too much traffic...when users are on the system, the various dashboard monitors go up and then flat line the rest of the time. This week, the CPU time when way up when there were no requests and data going in or out of the site. Is there a way to determine the cause of this CPU activity when the site is not active? It doesn't make sense to me that I should have CPU activity being assigned to my site when there is to site activity.
If your website has significant processing at application start, it is possible your VM got rebooted or your app pool recycled and your onstart handler got executed again (which would cause CPU to spike without any request).
You can analyze this by adding application logs to your Application_Start event (but after initializing trace). There is another comment detailing how to enable logging, but you can also consult this link.
You need to collect data to understand what's going on. So first thing I would say is:
1. Go to Azure management portal -> your website (assuming you are using Azure websites) -> dashboard -> operation logs. Try to see whether there is any suspicious activity going on.
download the logs for your site using any ftp client and analyze what's happening. If there is not much data, I would suggest adding more logging in your application to see what is happening or which module is spinning.
A great way to detect CPU spikes and even determine slow running areas of your application is to use a profiler like New Relic. It's a free add on for Azure that collects data and provides you with a dashboard of data. You might find it useful to determine the exact cause of the CPU spike.
We regularly use it to monitor the performance of our applications. I would recommend it.
Is there a way to enable Performance Counters to monitor Node.js application performance in Windows Azure?
I haven't experimented with it myself yet, but there is node-perfmon which is a wrapper around typeperf. That says it allows you to write performance counters, as well as simple memory / cpu monitoring. Is this the sort of monitoring you were looking for?
Just adding more to above answers..
For application stats monitoring on Node.js you can use Hummingbird. It supports status over http so you can integrate the code in your node.js app add one port to get the monitoring data over HTTP. No need to use Azure Storage Diagnostics and all info in real time in same machine. It's still in pre-alfa, but is handling with few tasks really well.
http://projects.nuttnet.net/hummingbird/
I know about the node.js "monitor" plugin which is the best for Linux machines for system specific performance and also use HTTP to provide system specific data. I am not sure if that can be ported to Windows Server but if can that is one great choice. Read more about monitor usage here:
http://www.sys-con.com/node/2275314
You may want to also look at these, they aren't directly using perfmon, but allow you to monitor the performance of your Node.js server:
http://search.npmjs.org/#/Probes.js
http://search.npmjs.org/#/nodetime
The NPM registry is a great tool for finding Node.js packages.