> What does the following error mean? One of my cassandra servers print this > error, and nodetool shows the state of the server is down. Netstat result > shows the socket number is very few.
The operating system enforced limits have been hit, so Cassandra is unable to create additional file descriptors (so it can't open files, TCP connections, etc). The correct fix is to ensure that Cassandra is running with higher operating system enforced limits (see ulimit, /etc/security/limits.conf, etc). Cassandra is not expected to deal with this type of error gracefully and you will want to restart nodes that run into this. -- / Peter Schuller (@scode on twitter)