1YAZ-LOG(7) Conventions and miscellaneous YAZ-LOG(7)
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6 yaz-log - Log handling in all yaz-based programs
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9 yaz-XXXX [-v loglevel,...] [-l logfile]
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12 All YAZ-based programs use a common log subsystem, and should support
13 common command line options for controlling it. This man page documents
14 those.
15
17 -l logfile
18 Specify the file where the log is to be written. If none is
19 specified, stderr is used. The log is appended to this file. If the
20 file grows overly large, it is silently rotated: It is renamed to
21 logfile.1, logfile.2, .., 9 (old such file is deleted), and a new
22 file is opened. The limit defaults to 1GB, but can be set by the
23 program. The rotating limit can be specified with option -r for the
24 YAZ frontend server (yaz-ztest).
25 Rotation can also be implicitly enabled by using a filename which
27 gets changed for a given date, due to substitutions as given by the
28 strftime(3) function.
29 -v loglevel
31 Specify the logging level. The argument is a set of log level
32 names, separated by commas (no whitespace!), optionally preceded by
33 a '-' to negate that level. Most programs have their own default,
34 often containing fatal,warn,log, and some application-specific
35 values. The default list can be cleared with the word none, or
36 individual bits can be removed by prefixing them with a dash '-'.
37
39 Some of the log levels control the way the log is written.
40 flush causes the log to be flushed after every write. This can have
42 serious implications to performance, and should not be used in
43 production. On the other hand, when debugging a program crash, this can
44 be extremely useful. The option debug implies flush as well.
45 notime prevents the writing of time stamps. This is intended for
47 automatic test scripts, which should produce predictable log files that
48 are easy to compare.
49
51 YAZ itself uses the following log levels:
52 fatal for fatal errors, that prevent further execution of the program.
54 warn for warnings about things that should be corrected.
56 debug for debugging. This flag may be used temporarily when developing
58 or debugging yaz, or a program that uses yaz. It is practically
59 deprecated, you should be defining and using your own log levels (see
60 below).
61 all turns on almost all hard-coded log levels.
63 loglevel logs information about the log levels used by the program.
65 Every time the log level is changed, lists all bits that are on. Every
66 time a module asks for its log bits, this is logged. This can be used
67 for getting an idea of what log levels are available in any program
68 that uses yaz-log. Start the program with -v none,loglevel, and do some
69 common operations with it. Another way is to grep for
70 yaz_log_module_level in the source code, as in
71 find . -name '*.[ch]' -print |
73 xargs grep yaz_log_module_level |
74 grep '"' |
75 cut -d'"' -f2 |
76 sort -u
77 eventl, malloc, nmem, odr are used internally for debugging yaz.
80
82 zoom logs the calls to the zoom API, which may be useful in debugging
83 client applications.
84
86 server logs the server functions on a high level, starting up,
87 listening on a port, etc.
88 session logs individual sessions (connections).
90 request logs a one-liner for each request (init, search, etc.).
92 requestdetail logs the details of every request, before it is passed to
94 the back-end, and the results received from it.
95 Each server program (zebra, etc.) is supposed to define its own log
97 levels in addition to these. As they depend on the server in question,
98 they can not be described here. See above how to find out about them.
99
101 See what log levels yaz-ztest is using:
102 yaz-ztest -1 -v none,loglevel
104 14:43:29-23/11 [loglevel] Setting log level to 4096 = 0x00001000
105 14:43:29-23/11 [loglevel] Static log bit 00000001 'fatal' is off
106 14:43:29-23/11 [loglevel] Static log bit 00000002 'debug' is off
107 14:43:29-23/11 [loglevel] Static log bit 00000004 'warn' is off
108 14:43:29-23/11 [loglevel] Static log bit 00000008 'log' is off
109 14:43:29-23/11 [loglevel] Static log bit 00000080 'malloc' is off
110 14:43:29-23/11 [loglevel] Static log bit 00000800 'flush' is off
111 14:43:29-23/11 [loglevel] Static log bit 00001000 'loglevel' is ON
112 14:43:29-23/11 [loglevel] Static log bit 00002000 'server' is off
113 14:43:29-23/11 [loglevel] Dynamic log bit 00004000 'session' is off
114 14:43:29-23/11 [loglevel] Dynamic log bit 00008000 'request' is off
115 14:44:13-23/11 yaz-ztest [loglevel] returning log bit 0x4000 for 'session'
116 14:44:13-23/11 yaz-ztest [loglevel] returning log bit 0x2000 for 'server'
117 14:44:13-23/11 yaz-ztest [loglevel] returning NO log bit for 'eventl'
118 14:44:20-23/11 yaz-ztest [loglevel] returning log bit 0x4000 for 'session'
119 14:44:20-23/11 yaz-ztest [loglevel] returning log bit 0x8000 for 'request'
120 14:44:20-23/11 yaz-ztest [loglevel] returning NO log bit for 'requestdetail'
121 14:44:20-23/11 yaz-ztest [loglevel] returning NO log bit for 'odr'
122 14:44:20-23/11 yaz-ztest [loglevel] returning NO log bit for 'ztest'
123 See the details of the requests for yaz-ztest
126 ./yaz-ztest -1 -v requestdetail
128 14:45:35-23/11 yaz-ztest [server] Adding static Z3950 listener on tcp:@:9999
129 14:45:35-23/11 yaz-ztest [server] Starting server ./yaz-ztest pid=32200
130 14:45:38-23/11 yaz-ztest [session] Starting session from tcp:127.0.0.1 (pid=32200)
131 14:45:38-23/11 yaz-ztest [requestdetail] Got initRequest
132 14:45:38-23/11 yaz-ztest [requestdetail] Id: 81
133 14:45:38-23/11 yaz-ztest [requestdetail] Name: YAZ
134 14:45:38-23/11 yaz-ztest [requestdetail] Version: 2.0.28
135 14:45:38-23/11 yaz-ztest [requestdetail] Negotiated to v3: srch prst del extendedServices namedresults scan sort
136 14:45:38-23/11 yaz-ztest [request] Init from 'YAZ' (81) (ver 2.0.28) OK
137 14:45:39-23/11 yaz-ztest [requestdetail] Got SearchRequest.
138 14:45:39-23/11 yaz-ztest [requestdetail] ResultSet '1'
139 14:45:39-23/11 yaz-ztest [requestdetail] Database 'Default'
140 14:45:39-23/11 yaz-ztest [requestdetail] RPN query. Type: Bib-1
141 14:45:39-23/11 yaz-ztest [requestdetail] term 'foo' (general)
142 14:45:39-23/11 yaz-ztest [requestdetail] resultCount: 7
143 14:45:39-23/11 yaz-ztest [request] Search Z: @attrset Bib-1 foo OK:7 hits
144 14:45:41-23/11 yaz-ztest [requestdetail] Got PresentRequest.
145 14:45:41-23/11 yaz-ztest [requestdetail] Request to pack 1+1 1
146 14:45:41-23/11 yaz-ztest [requestdetail] pms=1048576, mrs=1048576
147 14:45:41-23/11 yaz-ztest [request] Present: [1] 1+1 OK 1 records returned
148
152 A file with format my_YYYYMMDD.log (where Y, M, D is year, month, and
153 day digits) is given as follows: -l my_%Y%m%d.log . And since the
154 filename is depending on day, rotation will occur on midnight.
155 A weekly log could be specified as -l my_%Y%U.log.
157
159 prefix/include/yaz/log.h prefix/src/log.c
160
162 yaz(7) yaz-ztest(8) yaz-client(1) strftime(3)
163
165 Index Data
166YAZ 5.34.0 01/12/2023 YAZ-LOG(7)