I have decided use GWAN like my application server and I wish use voltdb for storage the data. Anybody has employed both together?.
I will develop it in C++.
In a recent online Game demo presented at the ORACLE Open World expo in SFO, we did not use voltDB but rather ORACLE noSQL, which is a Java (distributed) KV store.
Since we used G-WAN as a Database cache accelerator for 100 millions of records updated in realtime (on one single server), I guess that this experience is relevant in your case because voltDB does not handle this kind of TPS rates.
You say very little about your project so I will describe what we did in our demo: the C servlet created worker threads. Some were used to update the position (direction, orientation, speed) of the bots, and others were used to push the modifications to the remote Java-based noSQL KV store.
This allowed this same servlet to reply in realtime to human players that sent their new position and queried the lists of all nearby bots (also parallelized).
This was made possible by the fact that G-WAN supports both C and Java servlets: C offered compact data structures for the cache (100 millions of records consume a fair amount of RAM) and Java allowed G-WAN to talk to the noSQL DB.
I don't know what your application will be doing but at least you have an example of such a case using G-WAN and a (huge) DB that had to react in realtime.
G-WAN supports C and C++ servlets so you can use your favorite C++ libraries.
I work at VoltDB. We aren't aware of anyone who has tried this, but we had a similar question recently on our forum: http://community.voltdb.com/node/1862.
Related
I want to create an application that, when executed, has runtime functions that are accessible by other applications.
For example, a C++ application that stores values in files and retrieves this information. While this application is running, any other C++ applications could access it's save and retrieve functionality to save and retrieve data, but it should have no other connection to this system.
Sounds like a simple job for web services, or a remote database, or even an LDAP server.
Store and retrieve are operations common to all of these.
If the goal is to learn some specific technology, then ask a more specific question. Otherwise, don't reinvent any wheels. There are plenty of things out there for store and retrieve.
One of the simplest "store and retrieve" APIs I know of is Berkeley DB or Sleepycat.
We built a giant, clustered, simple key based database for a major telecom company using LDAP on top of Berkeley DB (aka Sleepycat). All open-source software and commodity hardware and it supports mission critical operations for millions of customers.
A more modern rendition of this might use memcached as well.
If you go HTTP based, you can use something simple as libcurl against an Apache web server to implement "RESTful" services with GET and PUT commands.
If you run it locally (same server), and access via localhost (127.0.0.1) then there is very little latency in the TCP stack, and it amounts to little more than memcpys at the kernel level.
simple message passing would do, say, JSON over ØMQ, or i.e. all in all, msgpack-rpc or protobuf-remote or Cap'n Proto RPC
What is a better mBaaS that supports offline sync and caching?
I am evaluating several mBaaS solutions for my hybrid mobile app under development. I looked at Kinvey, Kii, buddy, and Telerik BackEnd platform. I have also came across some open source solutions like openmobster and dreamfactory. I am looking to store data in sql-lite on mobile app and then sync it back with an online data store. Kinvey has this support, but their pricing model (per user) is not suitable in my scenario. I can see that openmobster does this but, how is what I need to understand? Can I host in on Azure VM or something? Also please suggest if there is any other solution commercial/open source capable of doing offline sync and caching with push notifications and data storage?
DreamFactory could be a good fit for your scenario. It is open source and comes with a full 30 days of free support. After which it's only like $25/month for a developer account - and this isn't even a requirement to use its product. It's specifically a support package.
To address your question a little more in-depth... I don't believe DreamFactory supports offline syncing at the moment, though they plan to very soon. In regards to sql-lite, DreamFactory's (DSP) product has a built in sql-lite driver to connect to that DB. However, it hasn't been tested enough for them to say it is a fully supported RDBMS. One of the beautiful things about DreamFactory is you're able to host the DSP (DreamFactory Service Platform) on Azure and Amazon EC2 instances (cloud solutions), host locally on your own server, or even use its own free hosted edition!
I would definitely take a little time to look into DF. It doesn't seem to me like you have much to lose. Especially, considering it's a free open-source product!
Feel free to ask me any questions you may have about DreamFactory!
-Mark
I am currently writing a client-server app for the iOS platform. The client is written in Obj-C, and the server uses C++ on OSX11.9. Since I intend to run the server software on an Ubuntu dedicated server, I am trying my best to keep the serverside code portable.
To store data about users and user-game-relations I intend to use an SQL database (most likely MySQL or possibly PostgreSQL since I'm familiar with those). I know that it is possible to read from/write to the database through a filedescriptor just like I do in my TCP module, but I wish to utilize a higher-level SQL communications API to make the programming process quicker.
Can anyone recommend me a good open source/free SQL API for *NIX C++? Any help would be appreciated. Thanks in advance!
You have several options here:
Use native database SDK. They are usually distributed along with the database installation or as separate downloads/packets. The upside is you can get maximum speed out of it. Downside is that you'll be limited by your initial choice - no switching afterwards without rewriting part of application.
Use a C++ ORM (example: ODB). This gives you DB independence along with some tasty features, at the cost of slightly reduced speed.
unixODBC supports both MySQL and PostgreSQL. Take a look at it.
I'm trying to figure out which database would suit my needs. My c++ project need a database that will be running on devices sold to customers. Mainly it would only log data and events to a database on local SSD disk. Write speed is the most important as logging frequency can be up to 1000Hz (1 write per 1ms). It must be possible to access data remotely from other devices to make graphic visualisations of data. I have tested sqlite with 3rd party server, mysql and postgres. Postgres seems to be quite slow compared to others. As I've read Postgres will become good if concurrency will increase, but in my case concurrency is and will be quite low.
I'm wondering is there any other database for such needs. It also feels that mysql and postgres will be a litte overkill for such requirements. Any suggestions?
PostgreSQL is an enterprise quality database, and not fit for embedded devices. MySQL while smaller will also be a tight fit in an embedded device. SQLite is the most common, and is widely used in embedded devices, even quite small.
Go for sqlite because your requirement states that you App will be running on DEVICES and mostly I guest they are mobile devices and almost all mobile devices support sqlite.... so go for it...
Consider BerkeleyDB. It is a small-footprint embedded DB with a big commercial backer if you needed support, etc. There are open source versions as well as commercially licensed ones. There's no support for SQL querying, but unless you're doing quite complex relational queries this should not be a problem. Concurrency support is excellent, though initial database configuration tends to be awkward.
There's a Microsoft-only alternative in the form of the Extensible Storage Engine, that's free and available on most versions of Windows. There are various other 'DBM'-like simple embedded databases out there, so long as you don't feel you need SQL.
You might also consider an in-memory 'NoSQL'-style database; something like Redis will be very performant.
RDM Embedded may be a good fit for you. I'm with Raima and this product allows you to access data remotely and you can utilize the in-memory or a hybrid on-disk/in-memory database capabilities (www.raima.com/in-memory-database) if you need to. What could be useful for you in this particular case is that RDM products can be used together to manage data between embedded, mobile, desktop or server devices. This can be easily setup through our products, RDM Embedded, RDM Mobile, RDM Workgroup and RDM Server.
If you want to test performance of our database quickly before downloading the full product, go to our Database Performance Popcorn Samples.
I want to try hooking up my pet project to a NOSQL type DB as eventually it will need to be able to process a large data volume with a very simple data structure...pretty much ideal for NOSQL.
However I am using C++ and have 0 interest in writing a wrapper around a C client. I googled some to try and find examples for using Cassandra with a C++ client and didn't find much.
So my requirements are: Free, Runs on Windows, Good C++ client with examples available that don't assume I am already a NOSQL / Thrift guru.
Any thoughts?
Redis has clients for most major programming languages, including C++. Everything I've been hearing is that Redis is the new hotness in NoSQL.
The thing about Redis (and memcached) is that they ultimately provide telnet-like interfaces. If you can open a socket to localhost and send commands, you can use the NoSQL database. That's more or less what Rediska (Redis PHP Client) does under the hood.
You should be able to whip up a dumb get-set interface in a few hours, and implement the remaining interfaces in a day or so.