Setting up syslogd on z/OS

Many components of TCPIP write information to syslogd. This is a process that captures the data sent to it over a UDP socket, and writes it to files in the Unix file system. If the syslogd is not active then messages may be written to the job log. When I was trying to set up AT-TLS, I had 10s of messages on the job log, each time a client tried to use AT-TLS.

The IBM documentation is not very clear, it tells you how to turn on debug, trace etc but does not clearly explain the difference, and when they are used.

It look like the PAGENT’s job is to take a configuration file, parse it, and pass the configuration data to TCPIP.

If you are using AT-TLS to set up TLS channels, the trace data comes from the TCPIP address space into syslogd.

Configure syslogd

See if SYSLOGD is running, if not, try to start it. If it does not exist…

  • Copy /usr/lpp/tcpip/samples/syslog.conf to its default configuration file /etc/syslog.conf, or another file.
  • Copy TCPIP.SEZAINST(SYSLOGD) to your proclib concatenation.
  • The program uses environment variables defined in STDENV to control operations. The default configuration file location is /etc/syslog.conf .

You can configure syslog.conf for example

*.TCPIP.*.* /var/log/%Y/%m/%d/TCPIP
*.SYSLOGD.*.* /var/log/%Y/%m/%d/syslogd
*.err /var/log/%Y/%m/%d/errors

This says all messages for SYSLOGD go to a file like /var/log/2022/05/14/syslogd, and error messages go to /var/log/2022/05/14/errors

This means you get a file of messages for each day. For me, I just used /var/log/syslogd.log and /var/log/errors.log, and deleted them periodically.

Priority

Data logged to syslogd has a “priority”. For example AT-TLS trace level 32 (Data) have a priority of “debug”. You can use this for example

*.TCPIP.*.debug     /var/log/TCPIPdebug 
*.TCPIP.*.*         /var/log/TCPIP 

This says

  1. for messages from TCPIP with priority debug or higher( debug, info, notice, warning, error, crit, alert, emerg) then write the data to /var/log/TCPIPdebug .
  2. Write all messages to /var/log/TCPIP

As debug is the lowest level of priority, these statements are effectively the same.

It may be better to have

*.TCPIP.*.debug     /var/log/TCPIPdebug 
*.TCPIP.*.warning   /var/log/TCPIP 

The priority can be “none” which means do not log any messages.

How do I capture messages not handled else where?

This is a bit clumsy.

When a message arrives each of the rules are check. If the check is true the message is logged.

You can have compound checks separated by a semicolon for a rule.

For example

*.*.*.* ; *.TCPIP.*.none ; *.PAGENT.*.none /var/log/all.log

This says log all messages – but not from TCPIP or PAGENT. If you have have one file for 20 jobs, you need to have 20 statements with the semicolon.

You can spread the definition over several lines. The semicolon at the end of the line says read next line. The code is not smart enough to put the /var/log/all on its own line, so using a ‘dummy’ may make it easier to maintain.

*.*.*.*; 
       *.TCPIP.*.none; 
       *.PAGENT.*.none;
       *.DUMMY.*.none /var/log/all 

Capturing the right data

If the config file you can specify options like

*.TCPIP.*.* /var/log/TCPIP
*.*.*. /var/log/all

The entries are Userid.Jobname.facility.priority.

PAGENT AT-TLS request are reported via TCPIP.

I could not find how to filter the TCPIP data so the AT-TLS data went to one file, and other TCPIP data went to another file. For TCPIP it looks like the “facility” is either “daemon” or “auth”, which

ISPF interface

There is an ISPF syslog browser tool which displays information about the logs, and helps you browse the logs of interest. The documentation for this is not very good.

I got this to work by experimentation. I created an exec like MYSYSLOG

/* Rexx */ 
address ispexec 
"LIBDEF ISPMLIB DATASET ID('TCPIP.SEZAMENU') STACK" 
"LIBDEF ISPPLIB DATASET ID('TCPIP.SEZAPENU') STACK" 
address tso "ALTLIB ACTIVATE APPLICATION(CLIST) 
              DATASET('TCPIP.SEZAEXEC') " 
"SELECT CMD(EZASYRGO) NEWPOOL PASSLIB NEWAPPL(EZAS)" 
address tso "ALTLIB DEACTIVATE APPLICATION(CLIST)" 
"LIBDEF ISPPLIB" 
"LIBDEF ISPMLIB" 

You can execute this from ISPF option 6 or have this built into the ISPF panels.

Originally this exec was called syslogd; when I used it, I got

SYSTEM COMPLETION CODE=4C5 REASON CODE=77A53217

Where 4C5 is TCPIP’s abend code and 3217 – the program has the wrong Authrorization Code (APF related). This is because there is a command syslogd which was executed in preference to my exec. When I renamed the exec to MYSYSLOG it used the exec and it worked fine!

The first panel is

EZASYP01 ----------------- z/OS CS Syslogd Browser ---------------- Row 1 of 1
Command ===>                                                  Scroll ===> PAGE
                                                                               
Enter syslogd browser options                                                  
  Recall migrated data sets ==> NO     (Yes/No) Recall data sets or not        
  Maximum hits to display   ==> 200    (1-99999) Search results to display     
  Maximum file archives     ==> 30     (0-400) Days to look for file archives  
  Display start date/time   ==> YES    (Yes/No) Retrieve start date/time       
  Display active files only ==> NO     (Yes/No) Active files only, no archives 
  DSN Prefix override value ==>                                                
                                                                               
Enter file or data set name of syslogd configuration, or select one from below:
                                                                               
  File/DS Name ==> /etc/syslog.conf
                                                                               
Press ENTER to continue, or press END PF key to exit without a selection       
                                                                               
Line commands: S Select, R Remove from list, B Browse content, E Edit content  
                                                                               
Cmd Recently used syslogd configuration file or data set name                  
--- -------------------------------------------------------------------------- 
    /etc/syslog.conf                                                          
******************************* Bottom of data ********************************

Pressing enter, gave me another panel with

EZASYP00 ----------------- z/OS CS Syslogd Browser ---------------- Row 1 of 6
OPTION ===>                                                   Scroll ===> PAGE
                                                                               
Select one of the following, or press END PF key to exit the syslogd browser   
                                                                               
  1 Change current syslogd configuration file and/or options                   
  2 Guide me to a possible syslogd destination                                 
  3 Clear guide-me hits (indicated by ==> in the Cmd column)                   
  4 Search across all active syslogd files                                     
                                                                               
Current config file ==> /etc/syslog.conf                                      
                                                                               
Line commands: B Browse, A List archives, S Search active file and archives,   
               SF Search active file, SA Search archives, I File/DSN info      
                                                                    Archive    
Cmd Rule/Active UNIX file name                    Start Time        Type Avail.
--- --------------------------------------------- ----------------- ---- ------
    *.SYSLOGD*.*.*                                28 May 2022 13:31 None 0     
    /var/log/syslogd                                                          
    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
    *.INETD*.*.*                                  Empty       N/A   None 0     
    /var/log/inetd                                                            
    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
    auth.*                                        Empty       N/A   None 0     
    /var/log/auth                                                             

I could then browse the error log for SYSLOGD.

You can search for userid, strings etc, and give date ranges.

However for my small, one person usage, I found it was easier to use Unix services and use the command

oedit /var/syslogd.log

to edit the file.

you can specify in the TTLS configuration. So not very useful.

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