The server will run singly on one instance of compute engine. What could limit it's serving capacity and how much load can a single instance (4 vCPUs and 15GB Memory) handle.
Note : I've already looked at Kubernetes and even load-balancing multiple instances but accessing the database from multiple clients is a little too complicated for me right now. So please keep in mind if you're going to suggest containerisation, that I'm a beginner.
Any and all advice is welcome. Thanks!
The serving capacity of the server depends on a number of factors, which includes the requests you receive from the clients, the additional applications running in it etc. For a 4 core CPU, as per this help center article, you will get a peak performance of 8Gb/s, which is good for a single instance. Since you are using a single parse server alone on the VM, it should work very well with the above-mentioned configuration.
A container is a tool for a developer. It contains all the dependencies and library which required to run/test a particular application in a container. The applications running in the container are easily portable.
There is this help center article which might give a precise idea of containers and its usage. While the Kubernetes Engine will help you to deploy/manage these containerized application.
Related
I am a little confuse about my message server's network bottleneck issue. I can obviously found the problem caused by the a lot of network operation, but I am not sure why and how to identify it.
Currently we are using GCP as our VM and 4 core/8G RAM for our message server. Redis & Cassandra is in other server at the same place. The problem happened at the network operation to the redis server and cassandra server.
I need to handle 3000+ requests at once to save data to redis and 12000+ requests to cassandra server.
My task consuming all my CPU power and the CPU usage down right after I merge the redis request and cassandra request to kind of batch request. The penalty is I have to delay my data saving.
What I want to know is how can I know the network's capability of my system. How many requests within 1 second is a reasonable task?. As my testing, this is obviously true that the bottleneck is the network operation, but I can't prove it. I can't even know how to estimate a reasonable network usage of my system? Are there some tools or other thing that can help to my make sure my network's problem? Or this is just a error config of my GCP system?
Thanks,
Eric
There is a "monitoring" label in each instance where you can check through graphs values like instance CPU, Network and RAM usage.
But to further check the performance of your instance you should use StackDriver Logging1 and Monitoring2. It stores a lot of information from the internal servers and the system performance. for that you will need to install the agent in the instance. It also stores information about your Load Balancer3, in case you are using one with your web application, which is very advisable since it scale your resources up or down with intelligent Autoscaling.
But in order to test out your network you will need to use some third party tool to overload the network. There are multiple tools to achieve this, like JMeter.
This is rather a set of questions than one very specific question. In the last couple weeks/days I puzzled together information regarding how to properly host a JAVA PLAY application "in the cloud", as lots of this information is scattered over different services, I felt like gathering up all these small pieces to one, because lots of things are important to be seen in full context. However, I moved my considerations to the bottom of the question, as they are mainly my opinions and subjective findings, which I don't want to be held responsible for. If I got something wrong, please don't hesitate to point that out.
Hosting Java PLAY + MySQL on AWS for world wide accessibility
Our Scenario: we have a quite straight forward application written within the Java PLAY framework (https://www.playframework.com/), working on iOS and Android as well as with a backend-system (for administration, content management and API), storing data in a MySQL DB. While most of the users' interactions with the server is quick and easy (login, sync some data) there are also some more data-intensive tasks (download some <100mb data zips to the mobile phone, upload a couple of mb to the server). Therefore we were looking for a solution to properly provide users far away from our servers with reasonable response times. The obvious next step was hosting in the cloud.
Hosting setup within AWS:
Horizontal scaling: for the start, only 1 EC2 instance with our app will be running in eu-1a. We will need to evaluate how much resources one instance actually requires, if more instances are needed and if more instances would actually benefit to quicker response times.
Horizontal scaling across regions: once the app generates heavy user load from another region, the whole EC2 instance should be duplicated and put to another region, running a db read replica (see Setting up a globally available web app on amazon web services and https://aws.amazon.com/de/blogs/aws/cross-region-read-replicas-for-amazon-rds-for-mysql/ ).
Vertical scaling of EC2 instances: in recent tests of the old hosting setup, the database proved to be the bottleneck rather than the play app and its server's hardware specifications. Therefore it is not yet fully clear how much vertical scaling would affect response times. If a t2.micro instance serves as good as a m3.xlarge instance, of course we would rather climb our way up from the bottom here.
Vertical scaling of RDS: we will need to estimate how much traffic hits the DB server and what CPU/RAM/etc will be required. Probably we will work our way up here aswell.
Global Redirection: done using Amazon Route 53 (?). A user from Tokio should be redirected to the EC2 instance running in Asia; a user from Rome to the EC2 instance in Europe. This does not only affect API calls within the app, but also content delivery (in both directions).
Open Questions regarding the setup
Is this setup conclusive? Am I missing crucial components?
Regarding global redirection: is Amazon Route 53 the right tool? How does it differ from CloudFront (which strikes me to be purely for content / media distribution?).
How do I define correct data/api endpoints for my app? Of course I don't want to define the database endpoint of a db read replica during app deployment. Will this also happen during the AR53 (question 2) setup? Same goes for API calls, of course the app should direct it's calls to https://myurl.com/api and from there it should be redirected. Is this realistic?
I would highly appreciate all kinds of thoughts (!), also regarding the background info written below. If you can point me to further reading to solve my questions on my own, I am also very thankful - there is simply a huge load of information regarding this, but this makes it hard to narrow the answers down. I do have knowledge in hosting/servers, but I am pretty sure there are true experts out there waiting to slap me with knowledge. :)
Background-Information
Current Hosting Setup: a load balancer distributes the traffic on 2 root linux servers, both of them running the PLAY app, one of them also holding the MySQL installation.
The current hosting setup has 3 big flaws:
No vertical scalability: the hosting company would take money for each scaling step. Currently the servers are running idle, but if the app booms, we could run short on capacity quickly. Running idle is still paid as if permanently under full load. This is expensive!
No deployment support: currently, we connect through SSH, manually deploy the correct folders to the file system, recompile on the server, set privileges, apply database evolutions; do the same for the second server (with different db connection parameters). What could possibly go wrong. ;)
No worldwide availability: to set up another server in another region of the world would mean a huge effort. To have a synchronized replica of our DB can be done, but once again deploying would mean downtime, room for errors and therefore time and money.
Hosting Options for Java PLAY:
There are lot of different blog posts about this. In short:
AWS: Amazon Web Services is one of the first places you start looking. Here you get everything that's possible, at a flexible price. You set yourself up an EC2 instance, a MySQL RDS and you're good to go - all of this in the free tier, so you can experiment, play around, test your stuff.
Microsoft Azure: similar to AWS regarding pricing and possibilities. However, I did not dive into setting up and deploying our application for test purposes.
Heroku: super easy deployment from within PLAY, scalable servers. However (on the first glance?) lacks possibility to supply remote regions with high speed content.
Jelastic: even easier deployment from within PLAY / IntelliJ IDEA. You push your app image to jelastic, jelastic distributes it further to their infrastructure providers.
RedHat OpenShift (https://www.openshift.com/): sounds promising, yet not as complete as AWS.
Lots of choices and possible setups/prices. Especially after finding out about deployment using boxfuse (https://cloudcaptain.sh/) I made my choice for AWS, as it offers absolutely all we need from 1 source. Boxfuse has low monthly costs but is perfectly integrated into AWS. Scaling is supported as well as the 3 common environments (dev/test/prod). Support is outstanding.
The setup looks good. I would however make one change: your large up- & downloads. As mobile speeds may not be ideal, have your app serve long-running requests is something you should avoid as this will needlessly tie up server threads. Instead consider having users upload and download straight from S3 using presigned URLs. You can then later add CloudFront to the mix when it makes financial sense to do so.
R53 will work just fine for picking the best server(s) for each end user.
For EC2 consider having an ELB + Auto-Scaling Group setup. Even just for a single instance you get the benefit of permanent health monitoring and auto-respawns. If you expect more load you can then auto-scale based on your expected bottleneck (cpu, network i/o). This will give you a more autonomous and robust setup than manually having to scale up and down based on your own monitoring analysis (even though the scaling part is very easy if you stick with immutable infrastructure & blue/green deployments like what Boxfuse offers).
Your focus on vertical server scaling might not serve you well on AWS. I would start thinking about horizontal scaling of app servers behind an Elastic Load Balancer, and possibly look into Elastic Beanstalk.
I'm not sure you can setup a read replica in another region via RDS, you might have to set that up via MySQL servers running on standard EC2 instances. And even if you can, that's going to be some expensive and high-latency data transfer.
If file uploads and downloads are all you are worried about, you just need to put CloudFront (Amazon's CDN service) in front of your application, and allow it to handle file uploads and downloads via its global edge servers. You could even do this without moving your entire application into AWS. I would recommend reading this blog post as a start.
I have to setup a server environment for a web application. I have to use aws, and so far it looks good for that purpose.
I need:
a scalable Tomcat 7 webapp server
session replication!
a mongodb database cluster(?)
As far as I think it could work with:
The scalable Tomcat 7 I can do easily with elastic beanstalk.
The session replication could work with elasticache
It seems like I have todo the mongodb cluster "manually", so I created some ec2 instances todo so.
I have some problems with that.
the costs would be quite high. The minimum setup would be 2 ec2 instances and one for the elasticache
The only thing, which autoscales, is the elastic beanstalk, means that I have to take care of that, too. (Well, for the mongodb instances, I could use a balancer, too)
In case of the mongodb ec2 instances, I need to setup each instance by myself
Do you have any idea how to:
lower the costs (Especially in the beginning, it would be a little much, no?)?
make the administration easier?
If you install mongo, have a look at: AWS_NoSQL_MongoDB.pdf. It is very customary to have one member of the replica set outside the availability zone you use, or even outside of the same region, so you can have a hot backup in case of a failure.
About prices - experiment (load test) and find the smaller instance type that fits you. Also, remember to shut down unused instances
About management - there is the AWS console and many 3rd party products. Also, Netflix have released some nice management tools.
Autoscaling for your web server is easily done with Elastic Beanstalk, but you can use it independently. Check out the documentation for autoscaling here: http://aws.amazon.com/autoscaling/
It has couple of features that will help you save most of your computation costs;
one is the ability to scale out (and most importantly in), by changing automatically the number of web server you are using, based on your load. You can define the minimum number (for example, 1) and the maximum number. The system can watch a set of metrics (number of requests, CPU load...) and decide when to add or subtract instances.
the second is the ability to change the scale policy and increase or decrease the size of the machines, based on your usage. You can use medium size instances and switch to large or extra large ones, if you find it more cost effective. You are encourage to try out different sizes to see what fits you best.
Using Elastic Cache, can help you both in the session replication, but also to lower the load on your DB machine. You can cache there your frequent queries output (front page, main category page...), and get better performance, and use fewer DB instances. It supports Memecached clients, which makes it very easy to develop in almost any programming language.
You should check Couchbase instead of MongoDB (see comparison). It is more robust and more reliable in scale.
Elastic BeanStalk is the best to reduce the over head of management for Web/App servers. However if haven't taken the development too far, I would recommend to use DynamoDB for the administration easement aspect.
However keep check on cost as well. Performance and Management is something really awesome in DynamoDB
I'm in the early stages of planning out a virtualised environment for our production system (Moodle). The layers are relatively simple:
web - Apache 2.2
Database - MySQL 5
PHP 5.2
My question is this, what is the generally accepted approach for distributing the above layers amongst phycsical servers? In this case, we are planning to have 2 physical servers. Should I aim to keep my web server cluster on a single physical server and database cluster on another? Or, replicate a full stack on both servers, in case one fails? Any insights into this would be a great help to me.
thanks,
Cathal.
We use separate (virtual) servers, but do maintain separate stacks on each simply because the overheads are small and it allows for flexibility if we want to scale up/down. This is not for fallback however, because if one server is so broken that it's not web accessible, you probably won't be able to get data off it and onto the second server in order for it to be a useful replacement. Use proper backups for fallback and practice restoring from them regularly.
Moodle generally blocks on the PHP side rather than the DB side and we see roughly 3.5:1 PHP:MySQL CPU loads when they are on separate machines. With that in mind, you need to consider what the maximum capacity of one server is: you will get best performance if you have no network overhead between the machines at all, so bigger is better. If you can't do it with one, then making 2 VMS, one larger for PHP and one smaller for MySQL is the best option, but do benchmark the differences under load for your particular setup (use Apache JMeter for this).
Our largest installs involve 70,000 users or so and we have two 4-CPU/8GB VMs, one for PHP and one for MySQL (although the DB one rarely goes above 30% CPU). This allows for about 400 concurrent connections via Apache. However, we are using a large farm of VMs and can scale up and down between 2 and 16 CPUs easily, so you may wish to consider one monster machine if you want flexibility.
For more information on Moodle performance, look here, particularly under 'scalability'.
although I've much experience writing code. I don't really have much experience deploying things. I am writing a project that uses mongodb for persistence, redis for meta-caching, and play for serving pages. I am deciding whether to buy a dedicated server vs buying multiple small/medium instance from amazon/linode (one for each, mongo, redis, play). I have thought of the trade-offs as below, I wonder if anyone can add to the list or provide further insights. I am leaning toward (b) buying two sets of instances from linode and amazon, so if one of them have an outage it will fail over to the other provider. Also if anyone has any tips for deploying scala/maven cluster or tools to do so, much appreciated.
A. put everything in one instance
Pros:
faster speed between database and page servlet (same host).
cheaper.
less end points to secure.
Cons:
harder to manage. (in my opinion)
harder to upgrade a single module. if there are installation issues, it might bring down the whole system.
B. put each module (mongo,redis,play) in different instances
Pros:
sharding is easier.
easier to create cluster for a single purpose. (i.e. cluster of redis)
easier to allocate resources between module.
less likely everything will fail at once.
Cons:
bandwidth between modules -> $
secure each connection and end point.
I can only comment about the technical aspects (not cost, serviceability, etc ...)
It is not mentioned whether the dedicated instance is a physical box, or simply a large VM. If the application generates a lot of roundtrips to MongoDB or Redis, then the difference will be quite significant.
With a VM, the cost of I/Os, OS scheduling and system calls is higher. These elements tend to represent an important part in the performance cost of efficient remote data stores like MongoDB or Redis, and the virtualization toll is higher for them.
From a system point of view, I would not put MongoDB and Redis/Play on the same box if the MongoDB database is expected to be larger than the available memory. MongoDB maps data files in memory, and relies on the OS to perform memory swapping. It is designed for this. The other processes are not. Swapping induced by MongoDB will have catastrophic consequences on Redis and Play response time if they are all on the same box. So I would at least separate MongoDB from Redis/Play.
If you plan to use Redis for caching, it makes sense to keep it on the same box than the Play server. Redis will use memory, but low CPU. Play will use CPU, but not much memory. So it seems a good fit. Also, I'm not sure it is possible from Play, but if you use a unix domain socket to connect to Redis instead of the TCP loopback, you can achieve about 50% more throughput for free.