Database Reference
In-Depth Information
nodetool upgradesstables
This will upgrade the existing sstables (with version 1.1.x) to a format
compatible with 1.2.9.
4.
Then, in sequence, follow the preceding steps for upgrading from
1.2.9 to 2.0.7, and then finally, perform the same for the upgrade from
version 2.0.7 to 2.1.
For a multi-node Cassandra cluster we need to perform the same steps over all the
nodes. If version upgrades fail on any node, we can try copying schema from another
node and replicate the data from other live nodes.
Troubleshooting Cassandra
Troubleshooting is the process of diagnosing and fixing problems. In this section, we
will troubleshoot a few common problems—such as having too many open files and
running out of memory—that you might encounter and have to troubleshoot.
Too Many Open Files
If you get an error like
java.net.SocketException: Too many open files
at java.net.Socket.createImpl(Socket.java:447)
at java.net.Socket.getImpl(Socket.java:510)
at java.net.Socket.setSoLinger(Socket.java:984)
it means you are hitting the limit of the maximum allowed open files. The default
value is 1024. With Cassandra, it is highly possible to exceed this limit. We can in-
crease this limit by modifying the
/etc/security/limits.conf
file like this:
root soft nofile 65535
Here
65535
is the number of file descriptors open. This should solve the issue.
Additionally, we can monitor the number of file descriptors by monitoring running
Java processes to validate whether it is a case of memory leak or not!
