OpsCenter 6.5 server startup reports TypeError exception for jnr.posix.POSIXHandler – DataStax Support

Summary

This article discusses a benign error reported during the OpsCenter server startup.

Applies to

OpsCenter 6.5.0 or newer

Symptoms

When starting the OpsCenter service, the following error appears in the startup.log:

02:04:49 [opscenterd] INFO: Opscenterd starting up...
02:04:51 [opscenterd] CRITICAL: Unhandled Error
Traceback (most recent call last):
  File "/usr/share/opscenter/lib/py/twisted/python/usage.py", line 411, in 
    fn = lambda name, value, m=method: m(value)
  File "/usr/share/opscenter/lib/py/twisted/application/app.py", line 486, in opt_reactor
    installReactor(shortName)
  File "/usr/share/opscenter/lib/py/twisted/application/reactors.py", line 80, in installReactor
    for installer in getReactorTypes():
  File "/usr/share/opscenter/lib/py/twisted/plugin.py", line 213, in getPlugins
    allDropins = getCache(package)
---  ---
  File "/usr/share/opscenter/lib/py/twisted/plugin.py", line 171, in getCache
    provider = pluginModule.load()
  File "/usr/share/opscenter/lib/py/twisted/python/modules.py", line 394, in load
    return self.pathEntry.pythonPath.moduleLoader(self.name)
  File "/usr/share/opscenter/lib/py/twisted/python/reflect.py", line 303, in namedAny
    topLevelPackage = _importAndCheckStack(trialname)
  File "/usr/share/opscenter/lib/py/twisted/python/reflect.py", line 303, in namedAny
    topLevelPackage = _importAndCheckStack(trialname)
  File "/usr/share/opscenter/lib/py/twisted/python/reflect.py", line 242, in _importAndCheckStack
    return __import__(importName)
  File "/usr/share/opscenter/lib/py/twisted/python/reflect.py", line 242, in _importAndCheckStack
    return __import__(importName)
  File "/usr/share/opscenter/lib/py/twisted/plugins/cred_sshkeys.py", line 23, in 
    from twisted.conch.checkers import (
  File "/usr/share/opscenter/lib/py/twisted/plugins/cred_sshkeys.py", line 23, in 
    from twisted.conch.checkers import (
  File "/usr/share/opscenter/lib/py/twisted/conch/checkers.py", line 15, in 
    import crypt
  File "/usr/share/opscenter/lib/jvm/jython-standalone-2.7.0.11.jar/Lib/crypt.py", line 6, in 

exceptions.TypeError: getPOSIX(): 1st arg can't be coerced to jnr.posix.POSIXHandler

Cause

A change to the "shading" of the JNR packages in OpsCenter has resulted in the libraries to not be in the expected place and cannot be located on startup. Twisted modules load the libraries on startup and generate the TypeError.

Solution

Despite being marked as CRITICAL in the logs, the error is benign and OpsCenter eventually starts up successfully without impact to its operation so the error can be safely ignored. An improvement to the way the shading is handled will be implemented in a future release of OpsCenter (OPSC-14912).