File: mon.8

package info (click to toggle)
mon 0.99.2-9
  • links: PTS
  • area: main
  • in suites: etch-m68k
  • size: 908 kB
  • ctags: 299
  • sloc: perl: 9,801; ansic: 778; sh: 372; makefile: 122
file content (1451 lines) | stat: -rw-r--r-- 40,364 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
.\" $Id: mon.8 1.11 Sat, 18 Aug 2001 15:37:53 -0400 trockij $
.TH mon 8 "$Date: Sat, 18 Aug 2001 15:37:53 -0400 $" Linux "Parallel Service Monitoring Daemon"
.SH NAME
mon \- monitor services for availability, sending alarms upon failures.
.SH SYNOPSIS
.B mon
.RB [ \-dfhlMSv ]
.RB [ \-a
.IR dir ]
.RB [ \-A
.IR authfile ]
.RB [ \-b
.IR dir ]
.RB [ \-B
.IR dir ]
.RB [ \-c
.IR config ]
.RB [ \-D
.IR dir ]
.RB [ \-i
.IR secs ]
.RB [ \-k
.IR num ]
.RB [ \-l
.IR dir ]
.RB [ \-m
.IR num ]
.RB [ \-p
.IR num ]
.RB [ \-P
.IR pidfile ]
.RB [ \-r
.IR delay ]
.RB [ \-s
.IR dir ]
.SH DESCRIPTION
.B mon
is a general-purpose scheduler for monitoring service availability
and triggering alerts upon detecting failures.
.B mon
was designed to be open in the sense that it supports arbitrary
monitoring facilities and alert methods via a common interface, which
are easily implemented through programs (in C, Perl, shell, etc.), 
SNMP traps, and special Mon (UDP packet) traps.

.SH OPTIONS
.TP
.BI \-a\  dir
Path to alert scripts. Default is
.IR /usr/local/lib/mon/alert.d:alert.d .
Multiple alert paths may be specified by separating them with
a colon.  Non-absolute paths are taken to be relative to the
base directory
.RI ( /usr/lib/mon
by default).
.TP
.BI \-b\  dir
Base directory for mon. scriptdir, alertdir, and statedir
are all relative to this directory unless specified from /.
Default is
.IR /usr/lib/mon .
.TP
.BI \-B\  dir
Configuration file base directory. All config files are located here, including
mon.cf, monusers.cf, and auth.cf.
.TP
.BI \-A\  authfile
Authentication configuration file. By default this is
.IR /etc/mon/auth.cf " if the " /etc/mon
directory exists, or
.I /usr/lib/mon/auth.cf
otherwise.
.TP
.BI \-c\  file
Read configuration from
.IR file .
This defaults to
.IR /etc/mon/mon.cf " if the " /etc/mon
directory exists, otherwise to
.IR /etc/mon.cf .
.TP
.BI \-d
Enable debugging mode.
.TP
.BI \-D\ dir
Path to state directory.  Default is the first of
.IR /var/state/mon ", " /var/lib/mon ", and " /usr/lib/mon/state.d
which exists.
.TP
.BI \-f
Fork and run as a daemon process. This is the
preferred way to run
.BR mon .
.TP
.BI \-h
Print help information.
.TP
.BI \-i\  secs
Sleep interval, in seconds. Defaults to 1. This shouldn't need to
be adjusted for any reason.
.TP
.BI \-k\  num
Set log history to a maximum of
.I num
entries. Defaults
to 100.
.TP
.BI \-l
Load state from the last saved state file. Currently the only
supported saved state is disabled watches, services, and hosts.
.TP
.BI \-L\ dir
Sets the log dir. See also
.B logdir
in the configuration file.  The default is
.B /var/log/mon
if that directory exists, otherwise
.BR log.d
in the base directory.
.TP
.B \-M
Pre-process the configuration file with the
macro expansion package
.IR m4 .
.\"
.\"
.\"
.TP
.BI \-m\  num
Set the throttle for the maximum number of processes to
.IR num .
.TP
.BI \-p\  num
Make server listen on port
.IR num .
This defaults to 2583.
.TP
.B \-S
Start with the scheduler stopped.
.TP
.BI \-P\  pidfile
Store the server's pid in
.IR pidfile ,
the default is the first of
.IR /var/run/mon/mon.pid ,
.IR /var/run/mon.pid ,
and
.IR /etc/mon.pid
whose directory exists.  An empty value tells
.B mon
not to use a pid file.
.TP
.BI \-r\  delay
Sets the number of seconds used to randomize the startup delay
before each service is scheduled. Refer to the global
.I randstart
variable in the configuration file.
.TP
.BI \-s\  dir
Path to monitor scripts. Default is
.IR /usr/local/lib/mon/mon.d:mon.d .
Multiple alert paths may be specified by separating them with
a colon.  Non-absolute paths are taken to be relative to the
base directory
.RI ( /usr/lib/mon
by default).
.TP
.BI \-v
Print version information.

.SH DEFINITIONS
.TP
.BI monitor
A program which tests for a certain condition, returns either true or
false, and optionally produces output to be passed back to the scheduler.
Common monitors detect host reachability via ICMP echo messages, or
connection to TCP services.
.TP
.BI period
A period in time as interpreted by the Time::Period module.
.TP
.BI alert
A program which sends a message when invoked by the scheduler.
The scheduler calls upon an alert when it detects a failure from
a monitor.
An alert program accepts a set of command-line arguments from the
scheduler, in addition to data via standard input.
.TP
.BI hostgroup
A single host or list of hosts, specified as names or IP addresses.
.TP
.BI service
A collection of parameters used to deal with monitoring a particular
resource which is provided by a group. Services are usually modeled after
things such as an SMTP server, ICMP echo capability, server disk space
availability, or SNMP events.
.TP
.BI watch
A collection of services which apply to a particular group.
.SH OPERATION
When the
.B mon
scheduler starts, it reads a configuration file to determine the
services it needs to monitor. The configuration file defaults to
.IR /etc/mon.cf ,
and can be specified using the
.BI \-c
parameter. If the
.B -M
option is specified, then the configuration file is pre-processed
with
.IR m4 .
If the configuration file ends with .m4, the file is also processed by
m4 automatically.

The scheduler enters a loop which handles client connections,
monitor invocations, and failure alerts. Each service has a timer,
specified in the configuration file as the
.BI interval
variable, which tells the scheduler how frequently to invoke a
monitor process.
The scheduler may be temporarily stopped. While it is stopped, client
access still functions, but it just doesn't schedule things. This
is useful in conjunction while resetting the server, because you can do this:
save the hosts and services which are disabled, reset the server
with the scheduler stopped, re-disabled those hosts and services,
then start the scheduler. It also allows making atomic changes
across several client connections.
See the
.B moncmd
man page for more information.

.SH MONITOR\ PROGRAMS
Monitor processes are invoked with the arguments specified in the
configuration file, appended by the hosts from the applicable
host group. For example, if the watch group is "servers", which contain
the hostnames "smtp", "nntp", and "ns", and the monitor line reads
as follows,
.br
\fC
monitor fping.monitor -t 4000 -r 2
\fR
.br
then the executable "fping.monitor" will be executed with these
parameters:
.br
\fC
MONITOR_DIR/fping.monitor -t 4000 -r 2 smtp nntp ns
\fR
.br

MONITOR_DIR is actually a search path, by default
.I /usr/local/lib/mon/mon.d
then
.IR /usr/lib/mon/mon.d ,
but it can be overridden by the
.BI \-s
option or in the configuration file.
If all hosts in the hostgroup have been disabled,
then a warning is sent to syslog and the monitor is
not run. This behavior may be overridden with the
"allow_empty_group" option in the service definition.
If the final argument to the "monitor" line is ";;"
(it must be preceded by whitespace),
then the host list will not be appended to the parameter list.

In addition to environment variables defined by
the user in the service definition,
.B mon
passes certain variables to monitor process.

.TP
.B MON_LAST_SUMMARY
The first line of the output from the last time the
monitor exited.

.TP
.B MON_LAST_OUTPUT
The entire output of the monitor from the last time it
exited.

.TP
.B MON_LAST_FAILURE
The time(2) of the last failure for this service.

.TP
.B MON_FIRST_FAILURE
The time(2) of the first time this service failed.

.TP
.B MON_LAST_SUCCESS
The time(2) of the last time this service passed.

.TP
.B MON_DESCRIPTION
The description of this service, as defined in the
configuration file using the
.I description
tag.

.TP
.B MON_DEPEND_STATUS
The depend status, "o" if dependency failure, "1" otherwise.

.TP
.B MON_LOGDIR
The directory log files should be placed,
as indicated by the
.I logdir
global configuration variable.

.TP
.B MON_STATEDIR
The directory where state files should be kept,
as indicated by the
.I statedir
global configuration variable.

.P
"fping.monitor" should return an exit status of 0 if it
completed successfully (found no problems), or nonzero if a problem
was detected. The first line of output from the monitor
script has a special meaning: it
is used as a brief summary of the exact failure which was detected, and
is passed to the alert program. All remaining output is also passed
to the alert program, but it has no required interpretation.

If a monitor for a particular service is still
running, and the time comes for
.B mon
to run another monitor for that service, it will not
start another monitor. For example, if the
.I interval
is 10s, and the monitor does not finish running
within 10 seconds, then
.B mon
will wait until the first monitor exits before
running another one.

.SH ALERT DECISION LOGIC
Upon a non-zero or zero exit status, the associated alert or upalert
program (respectively) is started,
pending the following conditions: If an alert for a specific
service is disabled, do not send an alert.
If
.B dep_behavior
is set to
.IR "'a'" ,
and a parent dependency is failing, then suppress the alert.
If the alert has previously been acknowledged, do not send
the alert, unless it is an upalert.
If an alert is not within the specified period, record the failure
via syslog(3) and do not send an alert.
If the failure does not fall within a defined period, do not
send an alert.
No upalerts are sent without corresponding down alerts,
unless
.B no_comp_alerts
is defined in the period section.
If an alert was already sent within the last
.B alertevery
interval, do not send another alert,
.I unless
the summary output from the current monitor program differs from the last
monitor process. Otherwise, send an alert using each alert program
listed for that period. The
.B "observe_detail"
argument to
.B alertevery
affects this behavior by observing the changes in the detail part
of the output in addition to the summary line.
If a monitor has successive failures and the
summary output changes in each of them,
.B alertevery
will not suppress multiple consecutive alerts.
The reasoning is that if the summary output changes, then
a significant event occurred and the user should be alerted.

.SH ALERT\ PROGRAMS
Alert programs are found in the path supplied with the
.BI \-a
parameter, or in the
.I /usr/local/lib/mon/alert.d
and
.I /usr/lib/mon/alert.d
directories if not specified.  They are invoked with the following command-line
parameters:

.TP
.BI \-s\  service
Service tag from the configuration file.
.TP
.BI \-g\  group
Host group name from the configuration file.
.TP
.BI \-h\  hosts
The expanded version of the host group, space delimited, but contained
in one shell "word".
.TP
.BI \-l\  alertevery
The number of seconds until the next alarm will be sent.
.TP
.BI \-O
This option  is  supplied  to an alert only if the
alert is being generated as a result of an expected traap timing out
.TP
.BI \-t\  time
The time (in
.BR time (2)
format) of when this failure condition
was detected.
.TP
.BI \-T
This option is supplied to an alert only if the alert was triggered by a trap
.TP
.B \-u
This option is supplied to an alert only if it is being
called as an upalert.

.P
The remaining arguments are supplied from the trailing parameters in
the configuration file, after the "alert" service parameter.

As with monitor programs, alert programs are invoked with environment
variables defined by the user in the service definition, in addition
to the following which are explicitly set by the server:

.TP
.B MON_LAST_SUMMARY
The first line of the output from the last time the
monitor exited.

.TP
.B MON_LAST_OUTPUT
The entire output of the monitor from the last time it
exited.

.TP
.B MON_LAST_FAILURE
The time(2) of the last failure for this service.

.TP
.B MON_FIRST_FAILURE
The time(2) of the first time this service failed.

.TP
.B MON_LAST_SUCCESS
The time(2) of the last time this service passed.

.TP
.B MON_DESCRIPTION
The description of this service, as defined in the
configuration file using the
.I description
tag.

.TP
.B MON_GROUP
The watch group which triggered this alarm

.TP
.B MON_SERVICE
The service heading which generated this alert

.TP
.B MON_RETVAL
The exit value of the failed monitor program, or return value
as accepted from a trap.

.TP
.B MON_OPSTATUS
The operational status of the service.

.TP
.B MON_ALERTTYPE
Has one of the following values: "failure", "up", "startup",
"trap", or "traptimeout", and signifies the type of alert which
was triggered.

.TP
.B MON_TRAP_INTENDED
This is only set when an unknown mon trap is received and caught
by the default/defaut watch/service. This contains colon
separated entries of the trap's intended watch group and service name.

.TP
.B MON_LOGDIR
The directory log files should be placed,
as indicated by the
.I logdir
global configuration variable.

.TP
.B MON_STATEDIR
The directory where state files should be kept,
as indicated by the
.I statedir
global configuration variable.

.P
The first line from standard input must be used as a brief summary
of the problem, normally supplied as the subject line of an email, or
text sent to an alphanumeric pager. Interpretation of all subsequent
lines read from stdin is left up to the alerting program. The usual
parameters are a list of recipients to deliver the notification to.
The interpretation of the recipients is not specified, and is up
to the alert program.

.SH CONFIGURATION FILE
The configuration file consists of zero or more hostgroup definitions,
and one or more watch definitions. Each watch definition may have one
or more service definitions. A line beginning with optional
leading whitespace and a pound ("#") is
regarded as a comment, and is ignored.

Lines are parsed as they are read. Long lines may be continued by ending
them with a backslash ("\\").  If a line is continued, then the backslash,
the trailing whitespace after the backslash, and the leading whitespace
of the following line are removed. The end result is assembled into a
single line.

.SS "Global Variables"
The following variables may be set to override compiled-in
defaults. Command-line options will have a higher precedence than
these definitions.

.TP
.BI "alertdir = " dir
.I dir
is the full path to the alert scripts. This is the value set by
the
.B \-a
command-line parameter.

Multiple alert paths may be specified by separating them with
a colon.  Non-absolute paths are taken to be relative to the
base directory
.RI ( /usr/lib/mon
by default).

When the configuration file is read, all alerts referenced from the
configuration will be looked up in each of these paths, and the full
path to the first instance of the alert found is stored in a hash. This
hash is only generated upon startup or after a "reset" command, so newly
added alert scripts will not be recognized until a "reset" is performed.

.TP
.BI "mondir = " dir
.I dir
is the full path to the monitor scripts. This value may also be
set by the
.B \-s
command-line parameter.

Multiple monitor paths may be specified by separating them with
a colon.  Non-absolute paths are taken to be relative to the
base directory
.RI ( /usr/lib/mon
by default).

When the configuration file is read, all monitors referenced from the
configuration will be looked up in each of these paths, and the
full path to the first
instance of the monitor found is stored in a hash. This hash is only
generated upon startup or after a "reset" command, so newly added monitor
scripts will not be recognized until a "reset" is performed.

.TP
.BI "statedir = " dir
.I dir
is the full path to the state directory.
.B mon
uses this directory to save various state information.

.TP
.BI "logdir = " dir
.I dir
is the full path to the log directory.
.B mon
uses this directory to save various logs, including
the downtime log.

.TP
.BI "basedir = " dir
.I dir
is the full path for the state, script, and alert directory.

.TP
.BI "cfbasedir = " dir
.I dir
is the full path where all the config files can be found
(monusers.cf, auth.cf, etc.).

.TP
.BI "authfile = " file
.I file
is the full path to the authentication file.

.TP
.BI "authtype = " "type [type...]"
.I type
is the type of authentication to use. A space-separated list of
types may be specified, and they will be checked the order they are
listed. As soon as a successful authentication is performed, the user
is considered authenticated by mon for the duration of the session and
no more authentication checks are performed.

If
.I type
is
.BR getpwnam ,
then the standard Unix passwd file authentication method will be used
(calls getpwnam(3) on the user and compares the crypt(3)ed version
of the password with what it gets from getpwnam). This will not work
if shadow passwords are enabled on the system.

If
.I type
is
.BR userfile ,
then usernames and hashed passwords are read from
.IR userfile ,
which is defined via the
.B userfile
configuration variable.

If
.I type
is
.BR pam ,
then PAM (pluggable authentication modules) will be used for authentication.
The service specified by the
.B pamservice
global will be used. If no global is given, the PAM
.B passwd
service will be used.

.TP
.BI "userfile = " file
This file is used when
.B authtype
is set to
.IR userfile .
It consists of a sequence of lines of the format
.BR "'username : password'" .
.B password
is stored as the hash returned by the standard Unix
crypt(3) function. 
.B NOTE:
the format of this file is compatible with the Apache file based
username/password file format. It is possible to use the
.I htpasswd
program supplied with Apache to manage the mon userfile.

Blank lines and lines beginning with # are ignored.

.TP
.BI "pamservice = " service
The PAM service used for authentication. This is applicable
only if "pam" is specified as a parameter to the
.B authtype
setting. If this global is not defined, it defaults
to
.BR "passwd" .

.TP
.BI "snmpport = " portnum
Set the SNMP port that the server binds to.

.TP
.BI "serverbind = " addr

.TP
.BI "trapbind = " addr

.B serverbind
and
.B trapbind
specify which address to bind the server and trap ports to, respectively.
If these are not defined, the default address is INADDR_ANY, which
allows connections on all interfaces. For security reasons,
it could be a good idea to bind only to the loopback interface.

.TP
.BI "snmp =" {yes|no}
Turn on/off SNMP support (currently unimplemented).

.TP
.BI "dtlogfile = " file
.I file
is a file which will be used to record the downtime log. Whenever
a service fails for some amount of time and then stop failing, this
event is written to the log. If this parameter is not set, no
logging is done. The format of the file is as follows (# is a
comment and may be ignored):

.BR "timenoticed group service firstfail downtime interval summary".

.B timenoticed
is the time(2) the service came back up.

.B "group service"
is the group and service which failed.

.B "firstfail"
is the time(2) when the service began to fail.

.B "downtime"
is the number of seconds the service failed.

.B "interval"
is the frequency (in seconds) that the service is polled.

.B "summary"
is the summary line from when the service was failing.

.TP
.BI "dtlogging = " yes/no

Turns downtime logging on or off. The default is off.

.TP
.BI "histlength = " num
.I num
is the the maximum number of events to be retained
in history list. The default is 100.
This value may also be set by the
.B \-k
command-line parameter.

.TP
.BI "historicfile = " file
If this variable is set, then alerts are logged to
.IR file ,
and upon startup, some (or all) of the past history is read
into memory.

.TP
.BI "historictime = " timeval
.I num
is the amount of the history file to read upon startup.
"Now" -
.I timeval
is read. See the explanation of
.I interval
in the "Service Definitions" section
for a description of
.IR timeval .

.TP
.BI "serverport = " port
.I port
is the TCP port number that the server should bind to. This value may also be
set by the
.B \-p
command-line parameter. Normally this port is looked up via getservbyname(3),
and it defaults to 2583.

.TP
.BI "trapport = " port
.I port
is the UDP port number that the trap server should bind to.
Normally this port is looked up via getservbyname(3),
and it defaults to 2583.

.TP
.BI "pidfile = " path
.I path
is the file the sever will store its pid in.  This value may also be set
by the
.B \-P
command-line parameter.

.TP
.BI "maxprocs = " num
Throttles the number of concurrently forked processes to
.I num.
The intent is to provide a safety net for the unlikely situation
when the server tries to take on too many tasks at once.  Note that this
situation has only been reported to happen when trying to use a garbled
configuration file! You don't want to use a garbled configuration
file now, do you?

.TP
.BI "cltimeout = " secs
Sets the client inactivity timeout to
.I secs.
This is meant to help thwart denial of service attacks or
recover from crashed clients.
.I secs
is interpreted as a "1h/1m/1s" string, where
"1m" = 60 seconds.

.TP
.BI "randstart = " interval
When the server starts, normally all services will not be scheduled
until the interval defined in the respective service section.
This can cause long delays before the first check of a service,
and possibly a high load on the server if multiple things are scheduled
at the same intervals.
This option is used to randomize the scheduling
of the first test for all services during the startup period, and
immediately after the
.I reset
command.
If
.I randstart
is defined, the scheduled run time of all services of all watch groups
will be a random number between zero and
.I randstart
seconds.

.TP
.BI "dep_recur_limit = " depth
Limit dependency recursion level to
.IR depth .
If dependency recursion (dependencies which depend on other dependencies)
tries to go beyond
.IR depth ,
then the recursion is aborted and a messages is logged to syslog.
The default limit is 10.

.TP
.BI "dep_behavior = " {a|m}
.B dep_behavior
controls whether the dependency expression
suppresses either the running of alerts or monitors
when a node in the dependency graph fails. Read more
about the behavior in the "Service Definitions" section
below.

This is a global setting which controls the default
settings for the service-specified variable.

.TP
.BI "syslog_facility = " facility
Specifies the syslog facility used for logging.
.B daemon
is the default.

.TP
.BI "startupalerts_on_reset = " {yes|no}

If set to "yes", startupalerts will be invoked when the
.B reset
client command is executed. The default is "no".


.SS "Hostgroup Entries"

Hostgroup entries begin with the keyword
.BR hostgroup ,
and are followed by a hostgroup tag and one or more hostnames
or IP addresses, separated by whitespace. The hostgroup tag must
be composed of alphanumeric
characters, a dash ("-"), a period ("."),
or an underscore ("_"). Non-blank lines following
the first hostgroup line are interpreted as more hostnames.
The hostgroup definition ends with a blank line. For example:

.RS
.nf
hostgroup servers nameserver smtpserver nntpserver
	nfsserver httpserver smbserver

hostgroup router_group cisco7000 agsplus
.fi
.RE

.SS "Watch Group Entries"

Watch entries begin with a line that starts
with the keyword
.BR watch ,
followed by whitespace and a single word which
normally refers
to a pre-defined hostgroup. If the second word is not recognized
as a hostgroup tag, a new hostgroup is created whose tag is
that word, and that word is its only member.

Watch entries consist of one or more service definitions.

There is a special watch group entry called "default". If a
default watch group is defined with a "default" service entry,
then this definition will be used in handling unknown mon
traps.

.SS "Service Definitions"

.TP
.BI service " servicename"
A service definition begins with they keyword
.B service
followed by a word which is the tag for this service.

The components of a service are an interval, monitor, and
one or more time period definitions, as defined below.

If a service name of "default" is defined within a watch
group called "dafault" (see above), then the default/default
definition will be used for handling unknown mon traps.

.TP
.BI interval " timeval"
The keyword
.B interval
followed by a time value specifies the frequency that
a monitor script will be triggered.
Time values are defined as "30s", "5m", "1h", or "1d",
meaning 30 seconds, 5 minutes, 1 hour, or 1 day. The numeric portion
may be a fraction, such as "1.5h" or an hour and a half. This
format of a time specification will be referred to as
.IR timeval .

.TP
.BI failure_interval " timeval"
Adjusts the polling interval to
.I timeval
when the service check is failing. Resets the interval
to the original when the service succeeds.

.TP
.BI traptimeout " timeval"
This keyword takes the same time specification argument as
.BI interval ,
and makes the service expect a trap from an external source
at least that often, else a failure will be registered. This is
used for a heartbeat-style service.

.TP
.BI trapduration " timeval"
If a trap is received, the status of the service the trap was delivered
to will normally remain constant. If
.B trapduration
is specified, the status of the service will remain in a failure
state for the duration specified by
.IR timeval ,
and then it will be reset to "success".

.TP
.BI randskew " timeval"
Rather than schedule the monitor script to run at the start of each
interval, randomly adjust the interval specified by the
.B interval
parameter by plus-or-minus
.B "randskew".
The skew value is specified as the
.B interval
parameter: "30s", "5m", etc...
For example if
.B "interval"
is 1m, and
.B "randskew"
is "5s", then
.I mon
will schedule the monitor script some time between every
55 seconds and 65 seconds.
The intent is to help distribute the load on the server when
many services are scheduled at the same intervals.

.TP
.BI monitor " monitor-name [arg...]"
The keyword
.B monitor
followed by a script name and arguments
specifies the monitor to run when the timer
expires. Shell-like quoting conventions are
followed when specifying the arguments to send
to the monitor script.
The script is invoked from the directory
given with the
.B \-s
argument, and all following words are supplied
as arguments to the monitor program, followed by the
list of hosts in the group referred to by the current watch group.
If the monitor line ends with ";;" as a separate word,
the host groups are not appended to the argument list
when the program is invoked.

.TP
.B allow_empty_group
The
.B allow_empty_group
option will allow a monitor to be invoked even when the
hostgroup for that watch is empty because of
disabled hosts. The default behavior is not
to invoke the monitor when all hosts in a hostgroup
have been disabled.

.TP
.BI description " descriptiontext"
The text following
.B description
is queried by client programs, passed to alerts and monitors via an
environment variable. It should contain a brief description of the
service, suitable for inclusion in an email or on a web page.

.TP
.BI exclude_hosts " host [host...]"
Any hosts listed after
.B exclude_hosts
will be excluded from the service check.

.TP
.BI exclude_period " periodspec"
Do not run a scheduled monitor during the time
identified by
.IR periodspec .

.TP
.BI depend " dependexpression"
The
.B depend
keyword is used to specify a dependency expression, which
evaluates to either true of false, in the boolean sense.
Dependencies are actual Perl expressions, and must obey all syntactical
rules. The expressions are evaluated in their own package space so as
to not accidentally have some unwanted side-effect.
If a syntax error is found when evaluating the expression, it
is logged via syslog.

Before evaluation, the following substitutions on the expression occur:
phrases which look like "group:service" are substituted with the value
of the current operational status of that specified service. These
opstatus substitutions are computed recursively, so if service A
depends upon service B, and service B depends upon service C, then
service A depends upon service C. Successful operational statuses (which
evaluate to "1") are "STAT_OK", "STAT_COLDSTART", "STAT_WARMSTART", and
"STAT_UNKNOWN".  The word "SELF" (in all caps) can be used for the group
(e.g. "SELF:service"), and is an abbreviation for the current watch group.

This feature can be used to control alerts for services which are
dependent on other services, e.g. an SMTP test which is dependent upon
the machine being ping-reachable.

.TP
.BI dep_behavior " {a|m}"
The evaluation of dependency graphs
can control the
suppression of either alert or monitor invocations.

.BR "Alert suppression" .
If this option is set to "a",
then the dependency expression
will be evaluated after the
monitor for the service exits or
after a trap is received.
An alert will only be sent
if the evaluation succeeds, meaning
that none of the nodes in the dependency
graph indicate failure.

.BR "Monitor suppression" .
If it is set to "m",
then the dependency expression will be evaulated
before the monitor for the service is about to run.
If the evaulation succeeds, then the monitor
will be run. Otherwise, the monitor will not
be run and the status of the service will remain
the same.

.SS "Period Definitions"

Periods are used to define the conditions which
should allow alerts
to be delivered.

.TP
.BI period " [label:] periodspec"
A period groups one or more alarms and variables
which control how often an alert happens when there
is a failure.
The
.B period
keyword has two forms. The first
takes an argument which is a
period specification from Patrick Ryan's
Time::Period Perl 5 module. Refer to
"perldoc Time::Period" for more information.

The second form requires a label followed by a period specification, as
defined above. The label is a tag consisting of an alphabetic character
or underscore followed by zero or more alphanumerics or underscores
and ending with a colon. This
form allows multiple periods with the same period definition. One use
is to have a period definition which has no
.B alertafter
or
.B alertevery
parameters for a particular time period, and another
for the same time period with a different
set of alerts that does contain those
parameters.

.TP
.BI alertevery " timeval [observe_detail]"
The
.B alertevery
keyword (within a
.B period
definition) takes the same type of argument as the
.B interval
variable, and limits the number of times an alert
is sent when the service continues to fail.
For example, if the interval is "1h", then only
the alerts in the period section will only
be triggered once every hour. If the
.B alertevery
keyword is
omitted in a period entry, an alert will be sent
out every time a failure is detected. By default,
if the summary output of two successive failures changes,
then the alertevery interval is overridden, and an alert
will be sent.
If the string
"observe_detail" is the last argument, then both the summary
and detail output lines will be considered when comparing the
output of successive failures. Please refer to the
.B "ALERT DECISION LOGIC"
section for a detailed explanation of how alerts are suppressed.

.TP
.BI alertafter " num"

.TP
.BI alertafter " num timeval"

.TP
.BI alertafter " timeval"
The
.B alertafter
keyword (within a
.B period
section) has three forms: only with the "num"
argument, or with the "num timeval" arguments,
or only with the "timeval" argument.
In the first form, an alert will only be invoked
after "num" consecutive failures.

In the second form,
the arguments are a positive integer followed by an interval,
as described by the
.B interval
variable above.
If these parameters are specified,
then the alerts for that period will only
be called after that many failures happen
within that interval. For example,
if
.B alertafter
is given the arguments "3\ 30m", then the alert will be called
if 3 failures happen within 30 minutes.

In the third form,
the argument is an interval,
as described by the
.B interval
variable above.
Alerts for that period
will only be called if the service has been
in a failure state for more than the length
of time desribed by the interval, regardless
of the number of failures noticed within that
interval.

.TP
.BI numalerts " num"

This variable tells the server to call no more than
.I num
alerts during a
failure. The alert counter is kept on a per-period basis,
and is reset upon each success.

.TP
.B "no_comp_alerts"

If this option is specified, then upalerts will be called whenever the
service state changes from failure to success, rather than only after
a corresponding "down" alert.

.TP
.BI alert " alert [arg...]"
A period may contain multiple alerts, which are triggered
upon failure of the service. An alert is specified with
the
.B alert
keyword, followed by an optional
.B exit
parameter, and arguments which are interpreted the same as
the
.B monitor
definition, but without the ";;" exception. The
.B exit
parameter takes the form of 
.B "exit=x"
or
.B "exit=x-y"
and has the effect that the alert is only called if the
exit status of the monitor script falls within the range
of the
.B exit
parameter. If, for example, the alert line is
.I "alert exit=10-20 mail.alert mis"
then
.I mail-alert
will only be invoked with
.I mis
as its arguments if the monitor
program's exit value is between 10 and 20. This feature
allows you to trigger different alerts at different
severity levels (like when free disk space goes from 8% to 3%).

See the
.B "ALERT PROGRAMS"
section above for a list of the pramaeters mon will pass 
automatically to alert programs.

.TP
.BI upalert " alert [arg...]"
An
.B upalert
is the compliment of an
.BR alert .
An upalert is called when a services makes the state transition from
failure to success, if a corresponding "down" alert
was previously sent. The
.B upalert
script is called supplying
the same parameters as the
.B alert
script, with the addition of the
.B \-u
parameter which is simply used to let
an alert script know that it is being called
as an upalert. Multiple upalerts may be
specified for each period definition.
Set the per-period
.B no_comp_alerts
option to 
send an upalert regardless if whether or not
a "down" alert was  sent.

.TP
.BI startupalert " alert [arg...]"
A
.B startupalert
is only called when the
.B mon
server starts execution.

.TP
.BI upalertafter " timeval"
The
.B upalertafter
parameter is specified as a string that
follows the syntax of the
.B interval
parameter ("30s", "1m", etc.), and
controls the triggering of an
.BR upalert .
If a service comes back up after
being down for a time greater than
or equal to the value of this option, an
.B upalert
will be called. Use this option to prevent
upalerts to be called because of "blips" (brief outages).

.SH "AUTHENTICATION CONFIGURATION FILE"
The file specified by the
.B authfile
variable in the configuration file (or
passed via the
.B "-A"
parameter) will be loaded upon startup.
This file defines restrictions upon which client
commands may be executed by which users. It is a
text file which consists of comments,
command definitions, and trap authentication parameters.
A comment line begins with optional
whitespace followed by pound sign. Blank lines are ignored.

The file is separated into a command section and a trap
section. Sections are specified by a single line containing
one of the following statements:

.RS
.nf
	command section
.fi
.RE

or

.RS
.nf
	trap section
.fi
.RE

Lines following one of the above statements apply to that section until
either the end of the file or another section begins.

A command definition consists of a command, followed by a colon,
followed by a comma-separated list of users who may execute the command.
The default is that no users may execute any commands unless they are
explicitly allowed in this configuration file. For clarity, a user can
be denied by prefixing the user name with "!". If the word "AUTH_ANY"
is used for a username, then any authenticated user will be allowed to
execute the command.

The trap section allows configuration of which users may send traps from
which hosts. The syntax is a source host (name or ip address), whitespace,
a username, whitespace, and a plaintext password for that user. If
the source host is "*", then allow traps from any host. If the username
is "*", then accept traps without regard for the username or password. If
no hosts or users are specified, then no traps will be accepted.

An example configuration file:

.RS
.nf
command section
list:		all
reset:		root,admin
loadstate:      	root
savestate:      	root

trap section
127.0.0.1	root	r@@tp4sswrd
.fi
.RE

This means that all clients are able to perform the
.B list
command, "root" is able to perform "reset", "loadstate", "savestate",
and "admin" is able to execute the "reset"
command.

.SH CLIENT\-SERVER\ INTERFACE
The server listens on TCP port 2583, which may be overridden using
the
.BI \-p\  port
option. Commands are a single line each, terminated by a newline.
Currently the server is iterative, accepting a single client at
a time. This will change in future releases.

.SH CLIENT\ INTERFACE\ COMMANDS

See manual page for
.BR moncmd .

.SH MON\ TRAPPING
Mon has the facility to receive special "mon traps" from any local
or remote machine. Currently, the only available method for
sending mon traps are through the Mon::Client perl interface,
though the UDP packet format is defined well enough to permit
the writing of traps in other languages.

Traps are handled similarly to monitors: a trap sends
an operational status, summary line, and description
text, and mon generates an alert or
upalert as necessary.

Traps can be caught by any watch/service group set up in
the mon configuration file, however it is suggested that
you configure watch/service groups specifically for
the traps you expect to receive. When defining a special
watch/service group for traps, do not include a "monitor"
directive (as no monitor need be invoked). Since a monitor
is not being invoked, it is not necessary for the watch
definition to have a hostgroup which contains real host names.
Just make up a useful name, and mon will automatically create
the watch group for you.

Here is a simple config file example:

.RS
.nf
watch trap-service
	service host1-disks
		description TRAP: for host1 disk status
		period wd {Sun-Sat}
			alert mail.alert someone@your.org
			upalert mail.alert -u someone@your.org

.fi
.RE

Since mon listens on a UDP port for any trap, a
default facility is available for handling traps to unknown
groups or services.
To enable this facility, you must include a "default" watch
group with a "default" service entry containing the specifics
of alarms.  If a default/default watch group and service are
not configured, then unknown traps get logged via syslog, and
no alarm is sent.
.B NOTE:
The default/default facility is a single entity as far as
accounting and alarming go. Alarm programs which are not
aware of this fact may send confusing information when a
failure trap comes from one machine, followed by a
success (ok) trap from a different machine. See the alarm
environment variable
.B MON_TRAP_INTENDED
above for a possible way around this. It is intended that
default/default be used as a facility to catch unknown
traps, and should not be relied upon to catch all traps
in a production environment. If you are lazy and only want
to use default/default for catching all traps,
it would be best to disable
upalerts, and use the MON_TRAP_INTENDED environment
variable in alert scripts to make the alerts more
meaningful to you.

Here is an example default facility:

.RS
.nf
watch default
	service default
		description Default trap service
		period wd {Sun-Sat}
			alert mail.alert someone@your.org
			upalert mail.alert -u someone@your.org

.fi
.RE

.SH EXAMPLES
The
.B mon
distribution comes with an
example configuration called
.IR example.cf .
Refer to that file for more information.

.SH SEE ALSO
.BR moncmd (1),
.BR Time::Period (3pm),
.BR Mon::Client (3pm)
.SH HISTORY
.B mon
was written because I couldn't find anything out
there that did just what I needed, and nothing was worth modifying
to add the features I wanted. It doesn't have a cool name, and
that bothers me because I couldn't think of one.
.SH BUGS
Report bugs to the email address below.
.SH AUTHOR
Jim Trocki <trockij@transmeta.com>