For those who integrated drools on GAE, can you please give some feedback on
the memory consumption (does it work with a F1 instance)?
startup time (initialization of KnowledgeBase)
do you serialize your KnowledgeBase objects to datastore?
do they fit in 1MB blobs?
And more generally, I'd like to know if it's a good idea to use drools on gae
Drools seems to run on GAE with some modifications as described here: https://code.google.com/p/red-piranha/wiki/ModifyDroolsRunInGoogleAppEngine#Modifications_to_allow_Drools_to_run_in_Google_App_Engine
For the statefulSession persistence, JPA seams to do the job but http://blog.athico.com/2013/05/creating-your-own-drools-and-jbpm.html explains the structure if I'll ever need to adapt (optimize for reading).
Finally, KnowledgeBase is serializable and can be saved as a blob in a desperate solution.
Related
Could someone explain the benefits/issues with hosting a database in Kubernetes via a persistent volume claim combined with a storage volume over using an actual cloud database resource?
It's essentially a trade-off: convenience vs control. Take a concrete example: let's say you pay Amazon money to use Athena, which is really just a nicely packaged version of Facebook Presto which AWS kindly operates for you in exchange for $$$. You could run Presto on EKS yourself, but why would you.
Now, let's say you want to or need to use Apache Drill or Apache Impala. Amazon doesn't offer it. Nor does any of the other big public cloud providers at time of writing, as far as I know.
Another thought: what if you want to migrate off of AWS? Your data has gravity as well.
Could someone explain the benefits/issues with hosting a database in Kubernetes ... over using an actual cloud database resource?
As previous excellent answer noted:
It's essentially a trade-off: convenience vs control
In addition to previous example (Athena), take a look at RDS as well and see what you would need to handle yourself (why would you, as said already):
Automatic backups
Multizone deployments
Snapshots
Engine upgrades
Read replicas
and other bells and whistles that come with managed service opposed to self-hosted/managed one.
But there is more to it than just convenience/control that this post I trying to shed light onto:
Kubernetes is adding another layer of abstraction there (pods, services...), and depending on way of handling storage (persistent volumes) you can have two additional considerations:
Access speed (depending on your use case this can be negligent or show stopper).
Storage that you have at hand might not be optimized for relational database type of I/O (or restrict you to schedule pods efficiently). The very same reasons you are not advised to run db on NFS for example.
There are several recent conference talks on kubernetes pointing out that database is big no-no for kubernetes (although this is highly opinionated, we do run average load mysql and postgresql databases in k8s), and large load/fast I/O is somewhat challenge to get right on k8s as opposed to somebody already fine tuned everything for you in managed cloud solution.
In conclusion:
It is all about convenience, controls and capabilities.
I am working on a project that we are going to put on Google Cloud.
There will be a member requirement so logins and profiles to store. Members will make projects that will be linked to their accounts. Other members can join these projects etc. Its not overly complex but I need it to be fast and scalable from the off.
I have a few (simple) questions about the best setup to go for.
Do I have a PHP front end if PHP is only in beta? Do I just use Python for the front end? Is there a better framework than others to use?
Do I create an App Engine API for the front end to call using Python or Java or something else?
Which database do I use? Do I go down the Compute Engine/MongoDB approach or just go straight for Google datastore? (MySQL is disregarded here)
Do I use a shared memcache or get a dedicated one?
These sort of things. It appears using Google Cloud is 'fairly' straight forward but would appreciate some pointers from those in the know who have already get their hands dirty, in a virtual sense of course!
Many thanks in advance
You appear to have four many-faceted Qs -- and apparently you aren't taking them to Google Groups so let me do my best here.
Do I have a PHP front end if PHP is only in beta? Do I just use Python
for the front end? Is there a better framework than others to use?
For guaranteed solidity use Python or Java - PHP and Go aren't quite as mature yet. Many Python frameworks are fine, from the very-lightweight webapp2 that comes with App Engine, through intermediate-weight ones such as "flask", all the way to rich "django". I'm personally a "frameworks shd stay out of my way!" guy so webapp2 is my own favorite.
Do I create an App Engine API for the front end to call using Python
or Java or something else?
Python and Java are both fully supported and stable. I personally of course prefer Python, but, hey!, that's just me! Endpoints, if that's what you mean by "an App Engine API", is also equally well supported each way, with Python perhaps a tad ahead in integration with the datastore thanks to https://github.com/GoogleCloudPlatform/endpoints-proto-datastore/tree/master/endpoints_proto_datastore .
Which database do I use? Do I go down the Compute Engine/MongoDB
approach or just go straight for Google datastore? (MySQL is
disregarded here)
I think the GAE datastore (with add-ons as needed, e.g to shunt images and videos off to Cloud Storage, or structured data for search including geo functionality to the Search API) is going to serve you fine.
Do I use a shared memcache or get a dedicated one?
Start with the shared (free) variety, then once you have it all working design and run stress load-tests and check how they perform with that vs a dedicated (paid) version. Do data-based decisions -- let the numbers guide you: how much better are you getting by paying $X/month for dedicated cache? Decide accordingly!-)
I have an application that is using JDBC to manipulate its data.
I'm looking for a way to run the application on Appengine. Unfortunately, it seems like there aren't many options besides datastore (which I just can't get used to).
I've tried to use an embedded JavaDB, but Appengine blocks FileOutputStream (throws an exception "java.io.FileOutputStream is a restricted class" on initial driver loading). Therefore, I haven't tried Sqlite.
I've also tried to use Jiql, a new project that offers a JDBC interface to Datastore. However, I just can't seem to establish a "connection". It is somewhat unclear to me how to use jiql (like: what user/pass do you supply?), despite the few examples on their site.
I've looked at Google Cloud SQL and eventually signed up for it. It seemed to be the perfect solution to our problem, until I realized it's a paid service (it'll be paid soon, once it leaves the beta phase). I prefer not to pay (yet) as I'm still testing and evaluating the potential of GAE.
--
What would you recommend, keeping in mind would like to use JDBC for the persistence layer of the application?
Thanks in advance!
GAE supports two frameworks for persistence, JPA and JDO. There are few frameworks that plays well with GAE rules like Objectify. But to start with datastore you can also take at google tutorial GAE DATASTORE. If you need to learn the relationship with JPA and support for JDBC persistence Check this Link
What is the current status of grails and google app engine deployment. I am new to app engine but wonder worth exploring it. Some specific qns are
the latest plugin, which has high user rating, has any restrictions? or it work seamlessly with all gorm features
is there any issue with high startup time for grails application. How is it in real world scenario? (with a typical small and large scale application)
what about other grails plugins (like, shiro, joda time, nimble etc). I guess they wont play well. So using those libraries directly is the better option
If decided to give up goole-app as a deployment option, how easy to switch to a normal environment. The JPA support ensures the compatibility with other traditional DBs?
Not sure what else are major issues.. probably, this is the foundation for a good discussion.
thanks.
I got few good response from grails mailing list, and the conclusion shares the comment by David. see the thread here
Couple of relevant responses:
From Tomas Lin:
I would suggest looking into Gaelyk if you really want to build a
project on the App Engine. It is built from the ground up with the App
Engine as the target engine, so it can bypass problems like long
loadtimes due to Spring and Hibernate. The newly introduced plugin
mechanism guarantees that your Gaelyk applications can be extended in
a way guaranteed to work on GAE.
Gaelyk has it's own native entity persistence DSL, which is a little
cleaner that the JPA/JDO abstractions on top of the App Engine.
I currently see many HardDeadlineExceeded exceptions with the App
Engine and Grails. It is just not designed to work well with Spring
right now. Hopefully this will improve with the later releases of
Groovy, Grails and the Spring / Google partnership for GAE for
business, but I wouldn't consider Grails on GAE production ready.
Even with Gaelyk, there are reports of slow performance. So imagine
the difficulties that arise with the much bigger Grails stack.
The app-engine comes with it's own implementation of a user / security
management system based on GMail accounts. If you just want to provide
an admin / non-admin implementation, this is supported in the
appengine configuration. Cannot comment on Shiro.
Be aware that one of the major restrictions of the App Engine is the
inability to write a file, so even basic file uploading in Spring
becomes problematic since the default mechanism writes to a temporary
file. I would imagine that most of the plugins would not work out of
the box without digging into their code and changing it.
I think the biggest issue here is lack of support for native JDBC. JPA
is not as well supported as plain JDBC GORM, things like named queries
would probably not work out of the box without retrofitting. If you
want to use the latest and greatest parts of Grails, it might be
worthwhile to consider other hosting solutions.
From Aaron Eischeid
1.The GAE plugin and the JPA-GORM plugins combined do not get you all GORM features seamlessly. Though you should get basics like .save(), .delete(), and maybe .list() the dynamic finders etc. are going to be out (at least for now). I could be way off here, but I think most/all Hibernate dependent features are out or replaced by something else (since it relies on SQL under the hood and GAE doesn't currently have SQL based DB...) so for example any criteria builders are a no go. It is unclear to me how much of the dot drilling you can do on objects. For example, not sure if you could do something like:
def b = new Book()
def stores = b.authors.publishers.bookstores
One place I could use some pointers is how to use JPA in the domain classes. I am sure there is good info out there, but I just haven't found it yet.
unsure
grails plugins that include domain classes or manipulate your current domain classes are bound to have issues since you have to construct your domain classes differently to play nice with JPA which is necessary because Googles Datastore isn't quite like a relational DB. On the flip side. you can use Google's built in security so you shouldn't necessarily need plugins like Acegi or Shiro.
This probably boils down to the different levels of GORM that you can use in controllers and services and the different ways you define domain classes. Some refactoring seems inevitable unless JPA plays just as nice with SQL DB's as it does with Googles Datastore. If JPA can move like that then transferring should be easy, but by using JPA-GORM you give up some stuff you would probably want if you weren't benefiting from due to being on GAE.
Eager to hear what others have to say,
Aaron
I am trying to scrape some website and republish the data as a RSS feed. How hard is this to setup with Google App Engine? Disadvantages and Advantages using GAE. Any recommendations and guidelines greatly appreciated!
Google AppEngine offers much more functionality (and complexity) than you will need if truly all you will want to do is republish some structured data as RSS.
Personally, I would use something like Yahoo pipes for a task like this.
That being said... if you want/need to get your feet wet with GAE, go for it!
Working with Google App Engine is pretty straight forward. I would recommend going through the Getting Started guide. It's short and simple and touches on essential GAE topics. There are more pros and cons than I will list here.
Pros:
In general, App Engine is designed for high traffic web applications that need to scale. Furthermore, it is designed from a programmer's perspective. Much of the scalability issues (database optimization, server administration, etc) are dealt with by Google. Having said that, I find it to be a nice platform. It is still being actively developed by Google engineers, and scheduling of tasks (a feature that has been long requested) is in the current road map.
Cons:
Perhaps the biggest downside right now is again the lack of official scheduling support and the quota limits currently set for free accounts. However you can't complain much if its free. Currently it only supports Python as a programming interface (although a new language [Java I predict] is coming soon). Furthermore, Python 2.6 (and 3.0 for that matter) are not yet supported. In addition, Django 1.0 is not officially supported in App Engine (although you can package Django 1.0 with your application).
Harder than it would be in most other technologies.
GAE can sort of do scheduled batch stuff like this now, but it's really not intended for that type of thing. Pick pretty much any other language and platform for this particular task, and you'll make your life a lot easier.
I think BeautifulSoup could run on GAE, so all your scraping needs are handled :D
Also, GAE has a geturl thingy. The only problem I think you might have is not having enough time to get the data (30 secs limitation).
I am working on a same project and I've decided that it's easier to prepare the data on another server and push them to GAE.
You might also want to look into Yahoo! Query Language (YQL)