I have ran into a strange problem several times now and I wonder if someone here has an solution for me:
For some of my data I want to keep track all the ID's I have used. To do that, I am putting the ID's as column into rows.
At first I wanted to put all ID's into one row (because the limit of 2 billion column seemed high enough) and then it happened:
For some reason I was no longer able to remove or update existing rows or column. Adding new rows and removing them was possible, but write access to the older rows did not longer work.
I have restarted the cluster, didn't help either. Only truncating the column family helped.
Because this happened several times after creating rows with 5.000+ columns I decided to reduce the number of columns to a maximum of 1.000 per row and everything is now working perfectly.
I am working on version 0.8-rc1 and for testing purpose I am running only one node with the default settings.
1) Because 0.8 is not marked as stable, is this a known problem?
2) Is there something in the configuration I need to change to handle a bigger number of columns?
3) Can I check on the cassandra-cli why updates are failing? (there were no error messages when trying deletes with the CLI manually)
4) Is there a recommended number of columns? (I guess this only depends on my systems memory?)
Thanks to everyone who took some time to read!