Appendix B. Problem Determination

This part of the Co:Z User's Guide contains information to help you diagnose problems with the Co:Z Launcher.

B.1 Common Configuration Issues

The following sections describe the symptoms of several common Co:Z configuration problems.

EDC8127I Connection timed out
cozagent: command not found
/usr/bin/cozagent: Permission denied
Host key verification failed
Permission denied (publickey,keyboard-interactive).
command not found for fromdsn or todsn on //STDERR DD

EDC8127I Connection timed out

If you receive a "EDC8127I Connection timed out" trying to ssh to your Target system, ensure that the ssh daemon (sshd) is started on the target machine. Confirm that you can connect by starting a local ssh session: ssh -p <port> userid@localhost. If you can connect locally, ensure that your firewall is not blocking access to your designated ssh port.

cozagent: command not found

Make sure that the Co:Z target toolkit has been downloaded and installed on the target system as described in the installation instructions. By default, the executables, including cozagent are installed in the directory /opt/dovetail/coz/bin. If the executables are installed in a different directory, set the agent-path property in your JCL to point explicitly to that alternate path.

/usr/bin/cozagent: Permission denied

This is likely due to not having the execute bit set on the Co:Z target executables. Locate the directory where they are installed and execute the following: chmod +x cozagent cozclient fromdsn todsn

Host key verification failed

Ensure that you have added the target system's host key to known_hosts of the userid running the Co:Z Launcher. This is discussed in the installation instructions, but a simple way to do this is to establish an ssh session with the target system from a USS command line and answer "yes" when prompted to add the host:

ZOS$ ssh user@68.255.253.94
The authenticity of host '68.255.253.94 (68.255.253.94)' can't be established.
RSA key fingerprint is 09:2c:46:23:56:4e:8f:15:ee:26:5a:12:ec:8d:3a:99.
Are you sure you want to continue connecting (yes/no)? yes
          

Permission denied (publickey,keyboard-interactive).

Usually due to an attempt to connect to a target server with a userid that doesn't have a keypair set up with the calling z/OS system. See the "Configure and test sshd" section in the Co:Z Target System Toolkits installation steps.

command not found for fromdsn or todsn on //STDERR DD

The z/OS Co:Z Launcher uses ssh to first launch the CoZAgent executable at the default path: /opt/dovetail/coz/bin/cozagent. CoZAgent then adds its own directory to the PATH before invoking the target program or shell.

This is sufficient on most Unix/Linux distributions, but some distributions such as SUSE have default login profiles that reconstruct the PATH variable from scratch, and lose this information when a new login shell is started. In these cases, you will need to update the login profile to include the /opt/dovetail/coz/bin directory

Assuming that your default shell is bash, here is an example that verifies that an existing PATH variable is not lost by a new login shell:

linux$ export PATH=foo:$PATH
linux$ bash --login
(a new shell)
linux$ echo $PATH
(check for the presence of "foo")
linux$ exit
          

If you find that your target distribution has this problem, you will need to update the /etc/profile file (or equivalent) to explicitly add the Co:Z binaries directory to the PATH.

B.2 Common Logging/Tracing Options

Several aspects control the logging of messages and trace information in the Co:Z toolkit:

The logging level

A threshold level: Error, Warning, Notice, Info (default), Debug, and Trace. Fine. Each message has a level and will only be logged if that level is at or below the current logging threshold.

The component's logger object

Each major component in the system will typically have its own logger, which can have its own threshold level set, or can use the default threshold.

The common logging destination

All logger messages eventually go to the same logging logging destination, which defaults to stderr, but a specific file, a user-written routine, or the SYSLOG facility may also be used.

Logging options are set using either the -L command-line switch or by by setting the COZ_LOG environment variable. In either case, the value of the setting is a list of one or more of the following values:

E|W|N|I|D|T|F

The default logging threshhold: Error, Warning, Notice, Info (default), Debug, Trace, Fine.

t

Prefix log messages with a system timestamp.

e

Include consumed cpu time in log messages.

f=filepath

Messages are logged to the given filepath instead of stderr.

s

Messages are logged to SYSLOG facility instead of stderr.

logname=E|W|N|I|D|T|F

Set a specific log name to the given threshold

B.3 Enabling Component Logging

The following examples demonstrate how to enable logging for various Co:Z toolkit components:

Set the default logging threshold for the batch launcher job

The following example uses the -LT command switch to set the default logging level to "Trace" for all components in the batch launcher job (but not the target system components). The t option is also used to prefix all messages with a timestamp.

	
//COZLG1  JOB (),'COZ' 
//STEP1   EXEC PROC=COZPROC, 
//        ARGS='-LT,t myuid@linux1.myco.com' 
//COZCFG DD * 
server-env-COZ_LOG=T,t
//STDIN   DD * 
# This is input to the remote shell
echo "We are running on: " `uname -sr`
// 
      

Set the default logging threshold for the target system components

The following example uses the agent-options property to set the -L command line switch to configure CoZAgent logging.

The example also sets the target system environment variable COZ_LOG to set logging options for all other target components. Environment variables for the target system can be set using the target-env- property prefix in the Co:Z Launcher configuration properties DD (COZCFGD).

//COZLG1  JOB (),'COZ' 
//STEP1   EXEC PROC=COZPROC, 
//        ARGS='myuid@linux1.myco.com' 
//COZCFG DD * 
agent-options=-LT,t
target-env-COZ_LOG=T,t
//STDIN   DD * 
# This is input to the remote shell
echo "We are running on: " `uname -sr`
// 
      

Enabling ssh diagnostic messages

It is sometimes useful to increase the verbosity of ssh itself to determine a problem source. To do this for the ssh client (used by the Co:Z Launcher process), add one or more v switches to ssh-options property in COZCFG:

//COZCFG DD * 
ssh-options=-vv
// 
      

More v's increase the debug level. Note that ssh can produce lots of output.

B.4 Co:Z Toolkit Component Overview

The following diagram illustrates the processes that occur (on z/OS and the target system) when running the Co:Z Launcher:


Saint Charles, Missouri
info@coztoolkit.com
+1 636.300.0901

Copyright© 2009 - 2022 Dovetailed Technologies, LLC. All rights reserved. Co:Z® is a registered trademark and Co:Z Toolkit™ is a trademark of Dovetailed Technologies, LLC.

Saint Charles, Missouri
info@coztoolkit.com
+1 636.300.0901

Copyright© 2009 - 2022 Dovetailed Technologies, LLC. All rights reserved. Co:Z® is a registered trademark and Co:Z Toolkit™ is a trademark of Dovetailed Technologies, LLC.