I am looking at using a system with Cassandra as a backend, and I wanted to collect together common problems that people experience in production Cassandra environments with usual workarounds/solutions.
Could anyone tell me of their experiences, as I want to see what potential showstoppers/issues I need to think about.
http://www.riptano.com/docs/0.6/troubleshooting/index
Related
I have Cassandra running in two different DC, and now it's time to scale it up and add more storage. Unfortunately, I'm not able to add storage on the existing partitions due to restrictions/limitations. I'd like to know would it be a good idea to use one common mount(NFS) to store the data. I know Cassandra is distributed across many nodes but can they share a common mount to access the data?
Thank you,
No, it is not a good idea to do that. Essentially, you're trading disk I/O for network I/O; so it'll perform terribly. Also, you're introducing a single point of failure into your cluster.
DataStax published a blog post on this a couple of years ago. The important thing to remember, is that blog posts don't usually happen about isolated incidents. They happen because someone sees the same thing causing problems over and over again, and they're trying to stop others from rationalizing that same mistake.
https://www.datastax.com/dev/blog/impact-of-shared-storage-on-apache-cassandra
I am looking for one complete end to end use case to practice on cassandra, can someone suggest a good one to me or can share examples. I have access to a 6 node cluster.
The only one I know, used with earlier Cassandra versions, is twissandra, a Twitter implementation in Cassandra. I think its abandoned as project but still valid for practice.
I personally think that any exercise simulating a social network behaviour is a good gym with nosql in general.
HTH, Carlo
I'm using Cassandra as the database and want to use Devise
Does Devise support Cassandra as the database? I looked around but did not find any information related to Devise-Cassandra on the wiki or anywhere else.
Is there third party plugins supporting it or other gem for authentication as devise?
Thank you
No, I have never heard of such thing.
Actually I suggest you keep your users in a more traditional database and use cassandra only for the most intensive I/O data.
Cassandra wasn't made to substitute other databases nor to be user with ORM (that's actually written in its official webpage)
I have been using CouchDB on some prototype applications and it has been brilliant, very easy to use and extremely quick. I was wondering if anyone has been using it in production and have any views on it's reliability, performance suitability for operational management etc ?? I am considering using it to support a service layer and would make use of its replication functionality.
Any comments/experiences would be most welcome.
I've used CouchDB for a few small in-house applications - it's been very stable and I've had no serious complaints. Setting that aside, a few small gripes -
1) Databases can be synchronized, but not nodes. That is, if you have four servers and twenty databases, you have to specify each server, and each database to synchronize. A minor gripe, but I prefer less management to more.
2) Since databases are append only, a database with a bunch of activity gets really big really quickly. Compacting fixes this, but isn't exactly fast, especially on big (e.g. 20 gigabytes) database. Scheduling compact for the weekends solved this, but doing that is probably less of an option for high availability applications.
3) Javascript is the de facto view language. What is not well advertised is that since CouchDB is written in Erlang, it also supports Erlang views, which are faster as they are "native". For applications doing a lot of operations in views, Erlang probably makes more sense.
Setting those minor issues aside, I'd wholeheartedly recommend it.
CouchDB ships in Ubuntu and is a fundamental component of the Ubuntu One service.
I have been using CouchDB on some prototype applications and it has been brilliant, very easy to use and extremely quick. I was wondering if anyone has been using it in production and have any views on it's reliability, performance suitability for operational management etc ?? I am considering using it to support a service layer and would make use of its replication functionality.
Any comments/experiences would be most welcome.
I've used CouchDB for a few small in-house applications - it's been very stable and I've had no serious complaints. Setting that aside, a few small gripes -
1) Databases can be synchronized, but not nodes. That is, if you have four servers and twenty databases, you have to specify each server, and each database to synchronize. A minor gripe, but I prefer less management to more.
2) Since databases are append only, a database with a bunch of activity gets really big really quickly. Compacting fixes this, but isn't exactly fast, especially on big (e.g. 20 gigabytes) database. Scheduling compact for the weekends solved this, but doing that is probably less of an option for high availability applications.
3) Javascript is the de facto view language. What is not well advertised is that since CouchDB is written in Erlang, it also supports Erlang views, which are faster as they are "native". For applications doing a lot of operations in views, Erlang probably makes more sense.
Setting those minor issues aside, I'd wholeheartedly recommend it.
CouchDB ships in Ubuntu and is a fundamental component of the Ubuntu One service.