Jelastic Poor Performance and Poor Support Issue - jelastic

Please explain me how containers are sharing hardware node resources between each other?
I feel my node is lack of CPU resources.
Even though I set maximum for cloudlets limit.
I have no real load on my node, but last month it very often stops responding for short periods and then restores with no actual reasons in logs.
I also feel my provider has poor experience with Jelastic administration.
Instead of looking for real reason why hardware node is overloaded, they just turn it off for a while and then turn it on.
See my screenshots. Zero CPU usage Zero CPU usage
Is it possible for hosting provider to "oversell" hardware node?
I am looking for support from Jelastic team here.

I know that you requested a reply from Jelastic in particular, but I suppose that it might help to get some insight from a hosting provider as well.
Is it possible for hosting provider to "oversell" hardware node?
The Jelastic platform itself does not have any limitations on this. The platform ensures that containers are distributed to the least loaded hardware nodes, but obviously if a hosting provider does not supply sufficient infrastructure / keep adding more, that distribution is worthless (i.e. all hardware is overloaded).
I feel my node is lack of CPU resources.
From those graphs it looks like you're hitting approx. 2GHz CPU, which for a LAMP application (right?) seems to be quite high. Are you sure that your bottleneck is CPU? If yes, how did you reach that conclusion / test that assertion?
I also feel my provider has poor experience with Jelastic administration.
Most of all, if you feel that your current Jelastic provider is not servicing your needs, did you consider moving to another one? The Jelastic ecosystem has over 30 different hosting providers. You can move your environment to another provider easily with the Export/Import feature and the ratings on the Jelastic Cloud Union site can help you to identify a good quality one in your preferred location.

Related

Minio Production Setup

I'm considering to perform a Minio on-prem setup and started wondering the pros and cons of having Minio deployed on VMs vs K8S operator.
Since I couldn't find any comparison (or experience sharing) on Google, I raising this topic here for any comments or additions.
Really appreciate any inputs.
VM or K8s, either way you're dealing with virtualization. The pros and cons of those don't have much to do with MinIO - MinIO has a Kubernetes Operator you can leverage for deploying onto K8s, or you can use some other VM-orchestration tooling out there - entirely up to you.
From a MinIO perspective, what really matters is ensuring you have the proper hardware components in place. Most important to performance is going to be network, storage controller, and storage (typically in that order). then CPU/Memory. Whether or not there is a virtualization layer doesn't really change much there - though I am aware of some issues with things like virtual network layers causing all kinds of problems, that's also outside of MinIO's purview.
We have some guidance here on production hardware guidance and sizing. Might be a good place to start.
More specific than that is really situation dependent - it requires taking into account your intended storage, growth targets, performance targets, things like that. The only thing I can think of that really differs from OnPrem to VMs or K8s is that with VMs/K8s you have to consider resource contention if you are using your worker nodes for a lot of workloads. It's no different than running a bunch of high-perf services on a baremetal node - if you don't have sufficient IO to handle what you throw at your services, your services will not perform.
This is all kinda vague, but that's how it goes - you have the docs above, MinIO's own reference hardware, and whatever you can get by reaching out directly.

Clustering Microservice Components

We have a set of Microservices collaborating with each other in the eco system. We used to have occasional problems where one or more of these Microservices would go down accidentally. Thankfully, we have some monitoring built around which would realize this and take corrective action.
Now, we would like to have redundancy built around each of those Microservices. I'm thinking more like a master / slave approach where a slave is always on stand by and when the master goes off, the slave picks it up.
Should we consider using any framework that we could use as service registry, where we register each of those Microservices and allow them to be controlled? Any other suggestions on how to achieve the kind of master / slave architecture with the Microservices that would enable us to have failover redundancy?
I thought about this for a couple of minutes and this is what I currently think is the best method, based on experience.
There are a couple of problems you will face with availability. First is always having at least one endpoint up. This is easy enough to do by installing on multiple servers. In the enterprise space, you would use a name for the endpoint and then have it resolve to multiple servers (virtual or hardware). You would also load balance it.
The second is registry. This is a very easy problem with API management software. The really good software in this space is not cheap, so this is not a weekend hobbyist type of software. But there are open source API Management solutions out there. As I work in the Enterprise space, I am very familiar with options like Apigee, CA, Mashery, etc. so I cannot recommend an open source option and feel good about myself.
You could build your own registry, if you desire. Just be careful how you design it, as a "registry of all interface points" leads to a service that becomes more tightly coupled.

Scaling Tigase XMPP server on Amazon EC2

Does anyone have an experience running clustered Tigase XMPP servers on Amazon's EC2, primarily I wish to know about anything that might trip me up that is non-obvious. (For example apparently running Ejabberd on EC2 can cause issues due to Mnesia.)
Or if you have any general advice to installing and running Tigase on Ubuntu.
Extra information:
The system I’m developing uses XMPP just to communicate (in near real-time) between a mobile app and the server(s).
The number of users will initially be small, but hopefully will grow. This is why the system needs to be scalable. Presumably for a just a few thousand users you wouldn’t need a cc1.4xlarge EC2 instance? (Otherwise this is going to be very expensive to run!)
I plan on using a MySQL database hosted in Amazon RDS for the XMPP server database.
I also plan on creating an external XMPP component written in Python, using SleekXMPP. It will be this external component that does all the ‘work’ of the server, as the application I’m making is quite different from instant messaging. For this part I have not worked out how to connect an external XMPP component written in Python to a Tigase server. The documentation seems to suggest that components are written specifically for Tigase - and not for a general XMPP server, using XEP-0114: Jabber Component Protocol, as I expected.
With this extra information, if you can think of anything else I should know about I’d be glad to know.
Thank you :)
I have lots of experience. I think there is a load of non-obvious problems. Like the only reliable instance to run application like Tigase is cc1.4xlarge. Others cause problems with CPU availability and this is just a lottery whether you are lucky enough to run your service on a server which is not busy with others people work.
Also you need an instance with the highest possible I/O to make sure it can cope with network traffic. The high I/O applies especially to database instance.
Not sure if this is obvious or not, but there is this problem with hostnames on EC2, every time you start instance the hostname changes and IP address changes. Tigase cluster is quite sensitive to hostnames. There is a way to force/change the hostname for the instance, so this might be a way around the problem.
Of course I am talking about a cluster for millions of online users and really high traffic 100k XMPP packets per second or more. Generally for large installation it is way cheaper and more efficient to have a dedicated servers.
Generally Tigase runs very well on Amazon EC2 but you really need the latest SVN code as it has lots of optimizations added especially after tests on the cloud. If you provide some more details about your service I may have some more suggestions.
More comments:
If it comes to costs, a dedicated server is always cheaper option for constantly running service. Unless you plan to switch servers on/off on hourly basis I would recommend going for some dedicated service. Costs are lower and performance is way more predictable.
However, if you really want/need to stick to Amazon EC2 let me give you some concrete numbers, below is a list of instances and how many online users the cluster was able to reliably handle:
5*cc1.4xlarge - 1mln 700k online users
1*c1.xlarge - 118k online users
2*c1.xlarge - 127k online users
2*m2.4xlarge (with 5GB RAM for Tigase) - 236k online users
2*m2.4xlarge (with 20GB RAM for Tigase) - 315k online users
5*m2.4xlarge (with 60GB RAM for Tigase) - 400k online users
5*m2.4xlarge (with 60GB RAM for Tigase) - 312k online users
5*m2.4xlarge (with 60GB RAM for Tigase) - 327k online users
5*m2.4xlarge (with 60GB RAM for Tigase) - 280k online users
A few more comments:
Why amount of memory matters that much? This is because CPU power is very unreliable and inconsistent on all but cc1.4xlarge instances. You have 8 virtual CPUs but if you look at the top command you often see one CPU is working and the rest is not. This insufficient CPU power leads to internal queues grow in the Tigase. When the CPU power is back Tigase can process waiting packets. The more memory Tigase has the more packets can be queued and it better handles CPU deficiencies.
Why there is 5*m2.4xlarge 4 times? This is because I repeated tests many times at different days and time of the day. As you can see depending on the time and date the system could handle different load. I guess this is because Tigase instance shared CPU power with some other services. If they were busy Tigase suffered from CPU under power.
That said I think with installation of up to 10k online users you should be fine. However, other factors like roster size greatly matter as they affect traffic, and load. Also if you have other elements which generate a significant traffic this will put load on your system.
In any case, without some tests it is impossible to tell how really your system behaves or whether it can handle the load.
And the last question regarding component:
Of course Tigase does support XEP-0114 and XEP-0225 for connecting external components. So this should not be a problem with components written in different languages. On the other hand I recommend using Tigase's API for writing component. They can be deployed either as internal Tigase components or as external components and this is transparent for the developer, you do not have to worry about this at development time. This is part of the API and framework.
Also, you can use all the goods from Tigase framework, scripting capabilities, monitoring, statistics, much easier development as you can easily deploy your code as internal component for tests.
You really do not have to worry about any XMPP specific stuff, you just fill body of processPacket(...) method and that's it.
There should be enough online documentation for all of this on the Tigase website.
Also, I would suggest reading about Python support for multi-threading and how it behaves under a very high load. It used to be not so great.

Is on-demand elasticity the only major feature of cloud computing that cannot be easily found with traditional hosting?

I am trying to compare cloud computing (on EC2) against traditional hosting on the following grounds to determine whether any of these features present unique benefits in the world of cloud computing versus more traditional hosting strategies:
Real-time monitoring
Server virtualization
Deployment automation
High performance computing
On-demand elasticity
As far as I can see, (1) monitoring is just as easy in both areas; (2) server virtualization is also present in both areas thanks to server farms which allow traditional hosts to beef up resources at will - and of course the same applies in the cloud; (3) deployment can be equally automated in both areas since the same tools often can be applied to both; (4) in the area of high performance computing maybe you get an extra boost from the cloud theoretically but I'm not so sure - you have to pay for that boost whether it's the cloud or not; (5) elasticity is the only real benefit that i can see of moving to the cloud - resources can be pumped up at the flick of a switch.
So my question is, is this really the only benefit of cloud computing from this list that offers a real benefit over traditional hosting or is my analysis flawed?
The main difference here is the cost model. While it's true you can gain all of the same benefits from your list with both Cloud Computing and traditional hosting, you pay up front for traditional hosting. You have to buy and maintain your own servers, while cloud computing allows you to pay a variable cost.
This is the reason cloud computing is so attractive for startup companies.
Not only do you have elasticity, but you have, in theory at least, a greater total amount of resources available than you could have with any static hosting solution.
Also, a side effect of elasticity is decreased electricity usage, which may or may not be a factor for you.
The company I work for is getting ready to move from self-hosting to a cloud provider (EC2). One thing I am greatly looking forward to is not having to worry about managing hardware. I don't need to worry about lead time for ordering parts. The need to have spare parts on-hand to cover unexpected hardware failures is gone. I don't need to worry about UPS or any power. We aren't big enough for cooling to be a concern... but now we never will have to worry about that either.
Depending on your own datacenter costs, a cloud computing platform can be much cheaper, as you don't need anybody to manage physical devices. Cloud services can provide bulk computing resources at likely a lower cost than you can provide if you bought the machines and hooked them up yourself.
Assuming your "traditional hosting" involves a single server, there is a very real benefit to high-performance computing in cloud / grid environments. Specifically, virtually unlimited performance, since you can have n cores working at the same time, whereas with a single server, you are limited by the maximum server capacity.
To put it more clearly, if the most powerful computer in the world is a 1000 - core system with 20 terabytes of RAM, then that's the most power you could have on a hosted server. However, a cloud consisting of 100 of these machines could do 100x the work in almost the same amount of time.
Additionally, it's generally less expensive (financially) to distribute work across multiple smaller machines than it is to get one powerful system capable of doing the same work.
And if you'd like to talk about disaster recovery....clouds can be geographically distributed, meaning if a tornado rips your data center out of the ground, plucks the server into little shards of metal and plastic, and embeds them in telephone poles...you experience a slight dip in your performance because your other 99 servers are still operating.
Elasticity of the computing, storage and network capacities is just a feature. Yet, it brings a huge number of economical benefits for the companies. For example, by implementing a Cloud Bursting scenario a small SaaS company could easily and cheaply handle traffic and usage spikes that might take an expensive hosted solution down.
Elasticity is only useful if you have a problem that can be solved horizontally. For example a web server to serve a static site, if the load increases, add more web servers to server the exact same content. On the other hand, even a simple blog site breaks under that scenario as comments entered into one server's database are not reflected in the other machines.
The resources to scale is not the same thing as the ability to scale. Cloud computing will not solve scalability issues with your application.
A good example of this is a video hosting site: using AWS to deliver the videos results in a disappointing experience since the EC2 cannot deliver the I/Ops necessary to deliver video. Throwing more machines at the problem won't solve the issue with how data gets from disk to network. (Yes I'm aware of the ridiculously expensive high-iops instances)

Why would you not want to use Cloud Computing [closed]

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Closed 10 years ago.
Our company is considering moving from hosting our own servers to EC2 and I was wondering if this was a good idea.
I have seen a lot of stuff about can cloud computing (and specifically EC2) do x, or can it do y, but my real question is why would you NOT want to use it?
If you were setting up a business, what are the reasons (outside of cost) that you would choose to go through the trouble of managing your own servers?
I know there are a lot of cost calculations you can put in regarding bandwidth, disk usage etc, but there are of course, other costs regarding maintenance of your own server. For the sake of this discussion I am willing to consider the costs roughly equal.
I seem to remember that Joel Spolsky wrote a little blur on this at one time, but I was unable to find it.
Anyone have any reasons?
Thanks!
I can think of several reasons why not use EC2 (and I am talking about EC2, not grid comp in general):
Reliability: Amazon makes no guarantee as to the availability / down time / safety of EC2
Security: Amazon does not makes any guarantee as to whom it will disclose your data
Persistence: ensuring persistence of your data (that includes, effort to set up the system) is complicated over EC2
Management: there are very few integrated management tools for a cloud deployed on EC2
Network: the virtual network that allows EC2 instances to communicates has some quite painful limitations (latency, no multicast, arbitrary topological location)
And to finish that:
Cost: on the long run, if you are not using EC2 to absorb peak traffic, it is going to be much more costly than investing into your own servers (cheapo servers like Supermicro cost just a couple of hundred bucks...)
On the other side, I still think EC2 is a great way to soak up non-sensitive peak traffic, if your architecture allows it.
Some questions to ask:
What is the expected uptime, and how does downtime affect your business? What sort of service level agreement can you get, what are the penalties for missing it, and how confident are you that the SLA uptime goals will be met? (They may be better or worse at keeping the systems up than you are.)
How sensitive is the data you're proposing to put into the cloud? Again, we get into the questions of how secure the provider promises to be, what the contractual penalties and indemnities are, and how confident you are that the provider will live up to the agreement. Further, there may be external requirements. If you deal with health-related data in the US, you are subject to very strict requirements. If you deal with credit card data, you also have responsibilities (contractual, not legal).
How easy will it be to back out of the arrangement, should service not be what was expected, or if you find a better deal elsewhere? This includes not only getting your data back, but also some version of the applications you've been using. Consider the possibilities of your provider going bankrupt (Amazon isn't going to go bankrupt any time soon, but they could split off a cloud provider which could then go bankrupt), or having an internal reorganization. Bear in mind that a company in serious trouble may not be able to live up to your expectations of service.
How much independence are you going to have? Are you going to be running their software or software you pick? How easy will it be to reconfigure?
What is the pricing scheme? Is it possible for the bills to hit unacceptable levels without adequate warning?
What is the disaster plan? Ideally, it's running your software on servers in a different location from where the disaster hit.
What does your legal department (or retained corporate attorney) think of the contract? Is there a dispute resolution mechanism, and, if so, is it fair to you?
Finally, what do you expect to get out of moving to the cloud? What are you willing to pay? What can you compromise on, and what do you need?
Highly sensitive data might be better to control yourself. And there's legislation; some privacy sensitive information, for example, might not leave the the country.
Also, except for Microsoft Azure in combination with SDS, the data stores tend to be not relational, which is a nuisance in certain cases.
Maybe concern that that big a company will more likely be approached by an Agent Smith from the government to spy on everyone that a little small provider somewhere.
Big company - more customers - more data to aggregate and recognize patterns - more resources to organize a sophisticated watch system.
Maybe it's more of a fantasy but who ever knows?
If you don't have a paranoia it doesn't mean yet that you are not being watched.
The big one is: if Amazon goes down, there's nothing you can do to bring it back up.
I'm not talking about doomsday scenarios where the company disappears. I mean that you're at the mercy of their downtime, with little recourse of your own.
Security -- you don't know what is being done to your data
Dependency -- your business is now directly intertwined with the provider
There are different kinds of cloud computing with lots of different vendors providing it. It would make me nervous to code my apps to work with a single cloud vendor. that you specifically had to code for..amazon and Microsoft I believe you need to specifically code for that platform - maybe google too.
That said, I recently jettisoned my own dedicated servers and moved to Rackspaces Mosso Cloud platform (which have no proprietary coding necessary) and I am really, really pleased with it so far. Cut my costs in half, and performance is way better than before. My sql server databases are now running on 64Bit enterprise SQL server versions with 32G of ram - that would have cost me a fortune on my previous providers infrastructure.
As far as being out of luck when the cloud is down, that was true if my dedicated server went down - it never did, but if there was a hardware crash on my dedicated server, I am not sure it would be back on-line any quicker than rackspace could bring their cloud back up.
Lack of control.
Putting your software on someone else's cloud represents handing over some control. They might institute a file upload size limit, or memory limits which could ruin your application. A security vulnerbility in their control panel could get your site hacked.
Security issues are not relevant if your application does its own encryption. Amazon is then storing encrypted data that they have no way of decrypting.
But in addition to the uptime issues, Amazon could decide to increase their prices to whatever they want. If you're dependent on them, you'll just have to pay it.
Depends how much you trust your own infrastructure in comparison to a 3rd party cloud service. In my opinion, most businesses (at least not IT related) should choose the later.
Another thing you lose with the cloud is the ability to choose exactly what operating system you want to run. For example, the latest Fedora Linux kernel available on EC2 is FC8, and the latest Windows version is Server 2003.
Besides the issues raised regarding dependability, reliability, and cost is the issue of data ownership. When you locate data on someone else's server, you no longer control who views, accesses, modifies, or uses that data. While the cloud operators can limit your access, you possess no way of limiting theirs or limiting who they give access to. Yes, you can encrypt all the data on the server but you lack any way of knowing who possesses root access to the server itself and any means to stop others from downloading your encrypted data and cracking it open. You lose control over your data; depending on what type of apps you are running and the proprietary nature of the data involved, this could engender corporate security and/or liability risks.
The other factor to consider is what would happen to your company if Amazon and/or EC2 were to suddenly vanish overnight. While a seemingly preposterous position, it could happen. Would you be able to quickly fill the hole and restore service, or would your potentially revenue generating apps languish while the IT staff scramble to obtain servers and bandwidth to get them back online? Also, what would happen to your data? The cloud hard drive holding all your information still exists, somewhere, and could pose a potential liability risk depending on the information you stored there--items such as personal information, business transaction records etc.
If I was starting my own business now, I would go through the hassle of purchasing and maintaining my own severs so I retained data ownership. I could control root access to the hardware, as well as control who can access and modify the data.
Unanswered security questions.
Really, do you want your IP out there, where you're not the one in control of it?
Most cloud computing environment are at least partially vendor specific. There's no good way to move stuff from one cloud to another without having to do a lot of rewriting. That sort of lock-in puts you at the mercy of one vendor when it comes to downtime, price increases, etc. If you rent or own your own servers, hosting providers and colos are pretty much interchangeable. You always have the option of moving somewhere else.
This may change in the future, as these things become standardized, but for now tying yourself to the cloud means tying yourself to a specific vendor.
This is kind of like the "Why would you use Linux" comment I received from management many years ago. The response I got was that it is a solution in search of a problem.
So what are your goals and objectives in moving to EC2?
I'd be interested to know if you'd still want to move to a cloud, if it was your own.
Cloud computing has brought parallel programming a little closer to the masses, but you still have to understand how best to use it - otherwise you're going to waste compute cycles and bandwidth.
Re-architecting your application for most efficient use of a cloud computing service is non-trivial.
Besides what has already been said here, we have to consider uniformity across the business. Are all of you applications going to be hosted in the cloud, or only most? Is most enough to pull the trigger on using the cloud when you still have to have personnel to handle a few special servers?
In particular, there might be special hardware that you need to communicate with such modems to accept incoming data, or voice cards that make automated phone calls. I don't know how such things could be handled in a cloud environment.

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