Frequently Asked Questions

I'm getting a Hector timeout on the queries, why?

Check the /var/log/cassandra/system.log and look for any errors. If you are doing a lot of deletes on your data you may see an error like this one:

ERROR [ReadStage:14] 2015-03-06 12:43:19,176 SliceQueryFilter.java (line 200) Scanned over 100000 tombstones in kairosdb.data_points; query aborted (see tombstone_failure_threshold).

One solution is to reduce your gc grace period as stated in this article: http://www.datastax.com/documentation/cassandra/2.0/cassandra/dml/dml_about_deletes_c.html

Why does the build for deb require X11?

Creating a debian package first builds an rpm and then uses alien to convert it to a deb. Alien requires the process to run as root so the build script will pop up a java dialog asking for the root password. You can get around this by passing the password on the build command like so

java make package-deb -D sudo=root_password

This will build the debian package without requiring X11