I am just trying to figure out if we can join different versions of riak kv in a cluster.
I currently run a 5 node cluster of riak-1.4.7. Can I join riak-2.0.X versions to the same cluster? If the answer is Yes, How is the data transfer will happen to the new node of different version?
I tried to search in official documents but I couldn't find what I am looking for.
Yes you can, some versions are compatible, this is for instance how you can migrate to a new version of Riak without any downtime. You should look at the migration documentation( for instance http://docs.basho.com/riak/kv/2.2.3/setup/upgrading/version/ )
In your case, you have a 1.4.7 cluster and you want to join a 2.0 to that cluster. I'm pretty sure that it'll work fine, as a lot of backward compatibility effort has been in done. Once that's done, you might want to think about upgrading all the nodes to the latest version though.
Related
wanted to get the opinion of the people for this one. Currently I am working on setting retention policies inside Artifacts in DevOps, I want to get some clarification on how exactly that works. For example: Lets say I set my Max number of version per package to 10 and my Days to keep recently downloaded packages 14. I currently have these versions for my builds:
3.0.1.1.4
3.0.2.1.2 - 3.0.2.1.8
3.1.2.0.1 - 3.1.2.0.4
Is it possible with azure retention policies to keep versions 3.0.1, even if its not the latest version of my build? I assume it will just save the 10 latest versions of the build which would be 3.0.2.1.2 - 3.1.2.0.4. Let me know if I am assuming correctly. Assume no packages have been downloaded for this scenario.
Another alternative I was thinking about using is maybe Artifactory, who to me seems fairly similar? Not really too sure about it. I want to know which one is best for retention policies overall to reduce cost. Any information help, I know its not the clear thing in the world so if you have any questions just let me know.
I have a question regarding some NoSQL databases. In Ehcache we have for example the JCache API, in MapDB the Map Interface and in Riak KV we have a own process with clusters. How do I exactly find out which database fits to which implementation type? For example for RocksDB (I assume that it is a process) and same for LevelDB.
For reference, RocksDB and LevelDB perform very similar functions and can be interchangeable in some situations.
Given your question of Is RocksDB and LevelDB just like Riak?, I can say that they are not the same as Riak provides a scalable distributed platform to run on that can connect to one or more backend databases simultaneoulsy (currently supported backends are Bitcask, LevelDB, Leveled and memory). RocksDB and LevelDB are essentially stand alone database platforms that can be used as such or can utilised by other software such as Riak as a backend. While you could technically implement RocksDB as a backend for Riak KV without needing a mountain of custom code, you probably wouldn't want to as RocksDB does not scale well.
How do I exactly find out which database fits to which implementation type? is rather a broad question. I think you might want to rephrase it as Which databases offer me {my list of desired implementations/functions}? to make it easier for community members to answer. Please note that some NoSQL databases have multiple uses available e.g. as you mentioned Riak KV, we have Maps, Sets, GSets, Flags, Registers, Solr Search, 2i and the standard CRDT options as well but some of those may be tied to other requirements e.g. 2i only works with a LevelDB/Leveled backend, Solr Search requires the Yokozuna package version of Riak KV 3.0.0 and above but is built in for all Riak 2.x.x versions etc.
What you may also want to try to do is download a few different options to a VM or bare metal rig, have a play and see how it works out. There are often cases where two competing products do something very similar on paper but in your specific use case, one outperforms the other significantly.
To get you started, here are links to Riak 2.9.8 (the latest release of the 2.x.x series) and to the Riak 2.2.6 docs (the 2.9.x docs should be out later this month).
I'm not sure if this has directly answered your question but, hopefully, it will give you some pointers as to where to go next.
TiDB provides so many different versions and the documentation also mentions different versions for users to install. How to avoid choosing the wrong TiDB version and TiDB-Ansible version? What's the difference between various TiDB master versions?
The TiDB community is highly active. After the 1.0 GA release, the engineers have been keeping optimizing and fixing bugs. Therefore, the TiDB version is updated quite fast. If you want to keep informed of the latest version, see TiDB Weekly update.
If you have questions regarding which version to use, email to info#pingcap.com for more information or file an issue.
It is recommended to deploy the TiDB cluster using the latest version of TiDB-Ansible, which will also be updated along with the TiDB version. TiDB has a unified management of the version number after the 1.0 GA release. You can view the version number using the following two methods:
select tidb_version()
tidb-server -V
How much data do I need to have to make use of Presto? The web site states that it can query data sizes from gigabytes to petabytes. I understand how it is used to query very large datasets, but is anyone using it for hundreds of gigabytes?
Currently, Presto is most useful if you already have an existing Hive installation. If you are using Hive, you should definitely try Presto. If all your data fits in a relational database like PostgreSQL or MySQL on a single machine, and you are happy with the performance, then keep using that.
However, Presto should be much faster than either of those databases on a single machine for analytic queries because it executes a query in parallel. Neither of those databases parallelize the execution of individual queries. At the moment, using Presto requires setting up HDFS and Hive (even on a single machine), so getting started will be more work than if you already have an existing Hive installation.
Or, you can take a look at Impala - which has been available as production-ready software for six months. Like Presto, Impala is a distributed SQL query engine for data in HDFS that circumvents MapReduce. Unlike Presto, there is a commercial vendor providing support (Cloudera).
That said, David's comments about data size still apply. Use the right tool for the job.
I am interested to create portal on cassandra services, since I faced some performance and scale issues starting from 1 million of records.
Definitely, it could be solved, but I am interested on other options.
My main issues is cost of updating all necessary indexes, to make reading fast.
First, is cassandra is good way for asp.net programmers? I mean, maybe there is some other projects, which worth to take a look
And second, can you provide any documentation samples on how to start with cassandra programming from C#?
since I faced performance and scale issues starting from 1 million of records.
Maybe your design was not that good, NoSQL is not a magic bullet for bad design. I have multi billion row tables and 95% of the response is sub second. Also what do you mean by updating indexes, do you mean updating statistics or rebuilding indexes?
since I faced performance and scale
issues starting from 1 million of
records.
You know, the one million mark for modern databases is where it is not something "totally ridiculously small" where you can ignore actually knowing what you do. Below one million is "tiny". I have a 800 million row table and get a LOT of sql running through with it - no problem at all.
First, is cassandra is good way for
asp.net programmers?
I would more suggest a basic book about SQL, reading the documentation and POSSIBLY throwing some hardware on the problem. As in: having totally bad hardware will kill all data management systems.
If you are using Cassandra for your .NET Application take a look at Aquiles. I developed it based on my company needs. If you find it useful or need any help let me know.
You can't really speak of Cassandra documentation. There's a myriad of partial tutorials on the web.
You may want to setup Linux in a virtual machine, because the windows build process is quite challenging, to say the least. (http://www.virtualbox.org, http://www.ubuntu.com)
Here's the howto:
http://www.ridgway.co.za/archive/2009/11/06/net-developers-guide-to-getting-started-with-cassandra.aspx
Note that the cassandra SVN url and the code sample have changed since the writing of this tutorial.
Here's another C# client:
http://github.com/mattvv/hectorsharp
And here some sample code:
http://www.copypastecode.com/26752/
Note that you need to download the latest Java Development Kit (JDK) from Sun for Linux.
It's not in the repositories of Ubuntu 10.04.
Then you need to type
export JAVA_HOME="/path/to/jdk"
in order for Cassandra to find your Java installation.
You might also want to take a look at:
http://en.wikipedia.org/wiki/NoSQL
Especially the taxonomy section is interesting.
Make sure Cassandra is the right type of NoSQL solution for your problem, e.g. use Neo4J if your problem actually is a graph problem.
Also, you need to make sure your NoSQL solution is ACID-compliant.
For example, Neo4J is the only ACID-compliant NoSQL graph engine.
Edit: Here's a jumpstart guide for Windows, without compiling:
http://coderjournal.com/2010/03/cassandra-jump-start-for-the-windows-developer/
http://www.ronaldwidha.net/2010/06/23/running-cassandra-on-windows-first-attempt/
http://www.yafla.com/dforbes/Getting_Started_with_Apache_Cassandra_a_NoSQL_frontrunner_on_Windows/
Instead of cassandra you might take a look at: ravendb. Supposedly it is a document store made with and created for .Net. It has Linq integration, and is (again supposedly) very fast.
As with any new technology, read if it helps you with your specific case, and check if it is proven technology (Do they have mainstream clients using it).
Before you go into this route see if you can't optimize your current solution first. Check if your queries are fast, if the indexes are done correctly, and if you can't remove load by adding caching.
Last nut not least, if adding some processors to your SQL machine might fix issues, it is typically a much cheaper solution.
If you want to do something new, then instead of going for noSQL, you might want to consider trying a database cluster.
The idea is when two machines each search half of the original database at the same time, you have half the search time without totally redesigning your existing database.