DataStax OpsCenter Documentation

Troubleshooting

This section lists some common problems experienced with OpsCenter and solutions or workarounds.

Cannot create a keyspace

Due to a Python 2.6 or earlier bug, some users experience a problem adding a keyspace using Data Modeling OpsCenter features. OpsCenter cannot save a newly created keyspace.

Upgrading Python generally fixes this problem.

Error exceptions.ImportError:libssl.so.0.9.8 displayed

Your CentOS 5.x, Debian, OEL 5.5, RHEL 5.x, or Ubuntu operating system has OpenSSL 1.0.0 installed and you see an error containing this message.

exceptions.ImportError: libssl.so.0.9.8

To correct this situation, install OpenSSL 0.9.8.

  • To install OpenSSL 0.9.8 on OEL and RHEL, run sudo yum install openssl098.
  • To install OpenSSL 0.9.8 on CentOS, Debian, or Ubuntu, run sudo apt-get install libssl0.9.8.

OpsCenter agent port setting conflict

If you have a problem with OpsCenter, check for conflicts in port settings. The OpsCenter Agent uses port 7199 by default. If you have not changed the default port, check that Cassandra or another process on the node, is not set up to use this port.

If you set the OpsCenter Agent port to a host name instead of an IP address, the DNS provider must be online to resolve the host name. If the DNS provider is not online, intermittent problems should be expected.

Limiting the metrics collected by OpsCenter

If you have many column families, the number of metrics OpsCenter collects can become quite large. For information about how to reduce the number keyspaces or column families that are monitored, see Controlling data collection.

Java not installed or JAVA_HOME environment variable not set

If Java is not installed or if OpsCenter cannot find JAVA_HOME, you may see an error such as:

/usr/share/opscenter-agent/bin/opscenter-agent: line 98: exec: -X: invalid option
exec: usage: exec [-cl] [-a name] [command [arguments ...]] [redirection ...]

To correct this problem, install Java or set JAVA_HOME:

export JAVA_HOME=<path_to_java>

Insufficient user resource limits errors

Insufficient resource limits may result in an insufficient nofiles error:

2012-08-13 11:22:51-0400 [] INFO: Could not accept new connection (EMFILE)

See Recommended settings under Insufficient user resource limits errors in the Cassandra documentation.