IV32548: DOC APAR: PROCESS AGENT AND NAME RESOLUTION ON STARTUP

APAR status

• Closed as documentation error.

Error description

• Behaviour of Process Agent on startup
  
  
  For each external automation or process that an OMNIbus Process
  Agent is requested to execute, a 'host' must be specified. This
  'host' is either defined in the PA's config file as part of a
  process' definition (refer: OMNIHOME/etc/nco_pa.conf) or in the
  external automation in the ObjectServer. This 'host' is not
  always in the same format. The design of the Process Agent was
  done in such a way that it can be flexible and respond to
  different formats  for the address and name of the host that it
  is running on. The reason for the variety of ways 'host' could
  be referred to is that it is often extracted from data elements
  in an event/alert. Depending on the source of an alert, the way
  it refers to a host could be an IP-address or a hostname etc.
  
  At startup the Process Agent builds up an internal list of all
  the local host's network interfaces. In building this list it
  resolves  the name for each network interface that it finds.
  This list enables the PA to map a given 'host' to any number of
  valid local interface host names. For example, the default
  hostname on a machine could simply be 'testbox' whereas a
  request could be sent to the PA asking for a process to be
  executed on 'testbox.company.com'. Or a request could be made
  using the ip-address in either ipv4 or ipv6 format. In all these
  examples, the PA should recognise that it could execute the
  process because they all refer to the same host, i.e. the local
  host that it is running on.
  
  If name resolution (e.g. via DNS or via Active Directory, etc.)
  is slow or not available, the PA could be slow to start up as it
  needs to wait for a timeout to occur on all host names that
  cannot be resolved. This in turn means that later on any process
  request that uses an unknown hostname will not execute. All such
  failures will be logged. A system administrator should hopefully
  be able to fix any network configuration issues on a host.
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All users of Tivoli Netcool/OMNIbus V7.3 (and later).        *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * The documentation does not describe how the process agent    *
  * handles host resolution at startup.                          *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * The updated documentation will be published in Q1 2013.      *
  ****************************************************************
  

Problem conclusion

• A new topic, -Host name resolution at start up-, has been added
  to describe how the process agent handles host names and
  addresses at start up. It contains the following content:
  
  Every external automation or process under the control of a
  process agent must have a specified host. The host is defined
  either in the process agent configuration file, as part of a
  process definition, or in the external automation in the
  ObjectServer. The default process agent configuration file is
  $NCHOME/omnibus/etc/nco_pa.conf.
  
  The process agent can handle host names and addresses that are
  specified in different formats. This is necessary because the
  host details are often extracted from data elements in an event
  or alert. Depending on the source of the alert, a host might be
  specified as an IP address or a host name, or in some other
  format.
  
  At startup, the process agent builds an internal list of all the
  local host's network interfaces, resolving the name of each
  network interface that it finds. This list enables the process
  agent to map a given host to any number of valid local interface
  host names. For example, the default host name on a machine
  might be ?testbox? but a request might be sent to the process
  agent asking for a process to
  be run on ?testbox.company.com?, or the request might specify
  the IPv4 or IPv6 address of the host. In each case, the process
  agent must recognize that the host referred to is the host that
  the process is running on.
  
  If host name resolution (using DNS or Active Directory, for
  example) is slow or is not available, the process agent might be
  slow to start because it must wait for a timeout to occur on all
  the host names that cannot be resolved. Also, any later process
  request that uses an unknown host name will not be run. Where a
  process is configured to start as a Windows service, and
  problems with DNS resolution
  cause it to start slowly, the service can timeout on startup.
  All such failures are logged. System administrators can use this
  information to fix any network configuration issues on affected
  hosts.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

Applicable component levels