yaz-log — Log handling in all yaz-based programs
yaz-XXXX [-v ] [loglevel,...-l ]logfile
All YAZ-based programs use a common log subsystem, and should support common command line options for controlling it. This man page documents those.
logfile
Specify the file where the log is to be written. If none is specified,
stderr is used. The log is appended to this file.
If the file grows overly large, it is silently rotated: It is renamed to
logfile.1,
logfile.2, .., 9
(old such file is deleted), and a
new file is opened. The limit defaults to 1GB, but can be set by the
program.
The rotating limit can be specified with option -r
for the YAZ frontend server (yaz-ztest).
Rotation can also be implicitly enabled by using a filename which gets changed for a given date, due to substitutions as given by the strftime(3) function.
loglevel
Specify the logging level. The argument is a set of log level names,
separated by commas (no whitespace!), optionally preceded by a '-' to
negate that level. Most programs have their own default, often
containing fatal,warn,log, and some
application-specific values. The default list can be cleared with the
word none, or individual bits can be removed by
prefixing them with a dash '-'.
Some of the log levels control the way the log is written.
flush causes the log to be flushed after every write.
This can have serious implications to performance, and should not be used
in production. On the other hand, when debugging a program crash, this can
be extremely useful. The option debug implies
flush as well.
notime prevents the writing of time stamps. This is
intended for automatic test scripts, which should produce predictable log
files that are easy to compare.
YAZ itself uses the following log levels:
fatal for fatal errors, that prevent further execution
of the program.
warn for warnings about things that should be corrected.
debug for debugging. This flag may be used temporarily
when developing or debugging yaz, or a program that uses yaz. It is
practically deprecated, you should be defining and using your own log
levels (see below).
all turns on almost all hard-coded log levels.
loglevel logs information about the log levels used by
the program. Every time the log level is changed, lists all bits that are
on. Every time a module asks for its log bits, this is logged. This can be
used for getting an idea of what log levels are available in any program
that uses yaz-log. Start the program with -v
none,loglevel, and do some common operations with it. Another way
is to grep for yaz_log_module_level in the source
code, as in
find . -name '*.[ch]' -print |
xargs grep yaz_log_module_level |
grep '"' |
cut -d'"' -f2 |
sort -u
eventl, malloc,
nmem, odr are used internally for
debugging yaz.
zoom logs the calls to the zoom API, which may be useful
in debugging client applications.
server logs the server functions on a high level,
starting up, listening on a port, etc.
session logs individual sessions (connections).
request logs a one-liner for each request (init, search,
etc.).
requestdetail logs the details of every request, before
it is passed to the back-end, and the results received from it.
Each server program (zebra, etc.) is supposed to define its own log levels in addition to these. As they depend on the server in question, they can not be described here. See above how to find out about them.
See what log levels yaz-ztest is using:
yaz-ztest -1 -v none,loglevel
14:43:29-23/11 [loglevel] Setting log level to 4096 = 0x00001000
14:43:29-23/11 [loglevel] Static log bit 00000001 'fatal' is off
14:43:29-23/11 [loglevel] Static log bit 00000002 'debug' is off
14:43:29-23/11 [loglevel] Static log bit 00000004 'warn' is off
14:43:29-23/11 [loglevel] Static log bit 00000008 'log' is off
14:43:29-23/11 [loglevel] Static log bit 00000080 'malloc' is off
14:43:29-23/11 [loglevel] Static log bit 00000800 'flush' is off
14:43:29-23/11 [loglevel] Static log bit 00001000 'loglevel' is ON
14:43:29-23/11 [loglevel] Static log bit 00002000 'server' is off
14:43:29-23/11 [loglevel] Dynamic log bit 00004000 'session' is off
14:43:29-23/11 [loglevel] Dynamic log bit 00008000 'request' is off
14:44:13-23/11 yaz-ztest [loglevel] returning log bit 0x4000 for 'session'
14:44:13-23/11 yaz-ztest [loglevel] returning log bit 0x2000 for 'server'
14:44:13-23/11 yaz-ztest [loglevel] returning NO log bit for 'eventl'
14:44:20-23/11 yaz-ztest [loglevel] returning log bit 0x4000 for 'session'
14:44:20-23/11 yaz-ztest [loglevel] returning log bit 0x8000 for 'request'
14:44:20-23/11 yaz-ztest [loglevel] returning NO log bit for 'requestdetail'
14:44:20-23/11 yaz-ztest [loglevel] returning NO log bit for 'odr'
14:44:20-23/11 yaz-ztest [loglevel] returning NO log bit for 'ztest'
See the details of the requests for yaz-ztest
./yaz-ztest -1 -v requestdetail 14:45:35-23/11 yaz-ztest [server] Adding static Z3950 listener on tcp:@:9999 14:45:35-23/11 yaz-ztest [server] Starting server ./yaz-ztest pid=32200 14:45:38-23/11 yaz-ztest [session] Starting session from tcp:127.0.0.1 (pid=32200) 14:45:38-23/11 yaz-ztest [requestdetail] Got initRequest 14:45:38-23/11 yaz-ztest [requestdetail] Id: 81 14:45:38-23/11 yaz-ztest [requestdetail] Name: YAZ 14:45:38-23/11 yaz-ztest [requestdetail] Version: 2.0.28 14:45:38-23/11 yaz-ztest [requestdetail] Negotiated to v3: srch prst del extendedServices namedresults scan sort 14:45:38-23/11 yaz-ztest [request] Init from 'YAZ' (81) (ver 2.0.28) OK 14:45:39-23/11 yaz-ztest [requestdetail] Got SearchRequest. 14:45:39-23/11 yaz-ztest [requestdetail] ResultSet '1' 14:45:39-23/11 yaz-ztest [requestdetail] Database 'Default' 14:45:39-23/11 yaz-ztest [requestdetail] RPN query. Type: Bib-1 14:45:39-23/11 yaz-ztest [requestdetail] term 'foo' (general) 14:45:39-23/11 yaz-ztest [requestdetail] resultCount: 7 14:45:39-23/11 yaz-ztest [request] Search Z: @attrset Bib-1 foo OK:7 hits 14:45:41-23/11 yaz-ztest [requestdetail] Got PresentRequest. 14:45:41-23/11 yaz-ztest [requestdetail] Request to pack 1+1 1 14:45:41-23/11 yaz-ztest [requestdetail] pms=1048576, mrs=1048576 14:45:41-23/11 yaz-ztest [request] Present: [1] 1+1 OK 1 records returned