1VARNISHD(1) VARNISHD(1)
2
3
4
6 varnishd - HTTP accelerator daemon
7
9 varnishd [-a
10 [name=][address][:port][,PROTO][,user=<user>][,group=<group>][,mode=<mode>]]
11 [-b [host[:port]|path]] [-C] [-d] [-F] [-f config] [-h type[,options]]
12 [-I clifile] [-i identity] [-j jail[,jailoptions]] [-l vsl] [-M
13 address:port] [-n name] [-P file] [-p param=value] [-r
14 param[,param...]] [-S secret-file] [-s [name=]kind[,options]] [-T
15 address[:port]] [-t TTL] [-V] [-W waiter]
16
17 varnishd [-x parameter|vsl|cli|builtin|optstring]
18
19 varnishd [-?]
20
22 The varnishd daemon accepts HTTP requests from clients, passes them on
23 to a backend server and caches the returned documents to better satisfy
24 future requests for the same document.
25
27 Basic options
28 -a
29 <[name=][address][:port][,PROTO][,user=<user>][,group=<group>][,mode=<mode>]>
30 Listen for client requests on the specified address and port. The
31 address can be a host name ("localhost"), an IPv4 dotted-quad
32 ("127.0.0.1"), an IPv6 address enclosed in square brackets
33 ("[::1]"), or a path beginning with a '/' for a Unix domain socket
34 ("/path/to/listen.sock"). If address is not specified, varnishd will
35 listen on all available IPv4 and IPv6 interfaces. If port is not
36 specified, port 80 (http) is used. At least one of address or port
37 is required.
38
39 If a Unix domain socket is specified as the listen address, then the
40 user, group and mode sub-arguments may be used to specify the per‐
41 missions of the socket file -- use names for user and group, and a
42 3-digit octal value for mode. These sub-arguments are not permitted
43 if an IP address is specified. When Unix domain socket listeners are
44 in use, all VCL configurations must have version >= 4.1.
45
46 Name is referenced in logs. If name is not specified, "a0", "a1",
47 etc. is used. An additional protocol type can be set for the listen‐
48 ing socket with PROTO. Valid protocol types are: HTTP/1 (default),
49 and PROXY.
50
51 Multiple listening addresses can be specified by using different -a
52 arguments.
53
54 -b <[host[:port]|path]>
55 Use the specified host as backend server. If port is not speci‐
56 fied, the default is 8080.
57
58 If the value of -b begins with /, it is interpreted as the abso‐
59 lute path of a Unix domain socket to which Varnish connects. In
60 that case, the value of -b must satisfy the conditions required
61 for the .path field of a backend declaration, see vcl(7). Back‐
62 ends with Unix socket addresses may only be used with VCL ver‐
63 sions >= 4.1.
64
65 -b can be used only once, and not together with f.
66
67 -f config
68 Use the specified VCL configuration file instead of the builtin
69 default. See vcl(7) for details on VCL syntax.
70
71 If a single -f option is used, then the VCL instance loaded from
72 the file is named "boot" and immediately becomes active. If more
73 than one -f option is used, the VCL instances are named "boot0",
74 "boot1" and so forth, in the order corresponding to the -f argu‐
75 ments, and the last one is named "boot", which becomes active.
76
77 Either -b or one or more -f options must be specified, but not
78 both, and they cannot both be left out, unless -d is used to
79 start varnishd in debugging mode. If the empty string is speci‐
80 fied as the sole -f option, then varnishd starts without start‐
81 ing the worker process, and the management process will accept
82 CLI commands. You can also combine an empty -f option with an
83 initialization script (-I option) and the child process will be
84 started if there is an active VCL at the end of the initializa‐
85 tion.
86
87 When used with a relative file name, config is searched in the
88 vcl_path. It is possible to set this path prior to using -f
89 options with a -p option. During startup, varnishd doesn't com‐
90 plain about unsafe VCL paths: unlike the varnish-cli(7) that
91 could later be accessed remotely, starting varnishd requires
92 local privileges.
93
94 -n name
95 Specify the name for this instance. This name is used to con‐
96 struct the name of the directory in which varnishd keeps tempo‐
97 rary files and persistent state. If the specified name begins
98 with a forward slash, it is interpreted as the absolute path to
99 the directory.
100
101 Documentation options
102 For these options, varnishd prints information to standard output and
103 exits. When a -x option is used, it must be the only option (it outputs
104 documentation in reStructuredText, aka RST).
105
106 -?
107 Print the usage message.
108
109 -x parameter
110 Print documentation of the runtime parameters (-p options), see
111 List of Parameters.
112
113 -x vsl Print documentation of the tags used in the Varnish shared mem‐
114 ory log, see vsl(7).
115
116 -x cli Print documentation of the command line interface, see var‐
117 nish-cli(7).
118
119 -x builtin
120 Print the contents of the default VCL program builtin.vcl.
121
122 -x optstring
123 Print the optstring parameter to getopt(3) to help writing wrap‐
124 per scripts.
125
126 Operations options
127 -F Do not fork, run in the foreground. Only one of -F or -d can be
128 specified, and -F cannot be used together with -C.
129
130 -T <address[:port]>
131 Offer a management interface on the specified address and port.
132 See varnish-cli(7) for documentation of the management commands.
133 To disable the management interface use none.
134
135 -M <address:port>
136 Connect to this port and offer the command line interface.
137 Think of it as a reverse shell. When running with -M and there
138 is no backend defined the child process (the cache) will not
139 start initially.
140
141 -P file
142 Write the PID of the process to the specified file.
143
144 -i identity
145 Specify the identity of the Varnish server. This can be accessed
146 using server.identity from VCL and with VSM_Name() from utili‐
147 ties. If not specified the output of gethostname(3) is used.
148
149 -I clifile
150 Execute the management commands in the file given as clifile
151 before the the worker process starts, see CLI Command File.
152
153 Tuning options
154 -t TTL Specifies the default time to live (TTL) for cached objects.
155 This is a shortcut for specifying the default_ttl run-time
156 parameter.
157
158 -p <param=value>
159 Set the parameter specified by param to the specified value, see
160 List of Parameters for details. This option can be used multiple
161 times to specify multiple parameters.
162
163 -s <[name=]type[,options]>
164 Use the specified storage backend. See Storage Backend section.
165
166 This option can be used multiple times to specify multiple stor‐
167 age files. Name is referenced in logs, VCL, statistics, etc. If
168 name is not specified, "s0", "s1" and so forth is used.
169
170 -l <vsl>
171 Specifies size of the space for the VSL records. Scaling suf‐
172 fixes like 'K' and 'M' can be used up to (G)igabytes. Default
173 is 80 Megabytes.
174
175 Security options
176 -r <param[,param...]>
177 Make the listed parameters read only. This gives the system
178 administrator a way to limit what the Varnish CLI can do. Con‐
179 sider making parameters such as cc_command, vcc_allow_inline_c
180 and vmod_path read only as these can potentially be used to
181 escalate privileges from the CLI.
182
183 -S secret-file
184 Path to a file containing a secret used for authorizing access
185 to the management port. To disable authentication use none.
186
187 If this argument is not provided, a secret drawn from the system
188 PRNG will be written to a file called _.secret in the working
189 directory (see opt_n) with default ownership and permissions of
190 the user having started varnish.
191
192 Thus, users wishing to delegate control over varnish will proba‐
193 bly want to create a custom secret file with appropriate permis‐
194 sions (ie. readable by a unix group to delegate control to).
195
196 -j <jail[,jailoptions]>
197 Specify the jailing mechanism to use. See Jail section.
198
199 Advanced, development and debugging options
200 -d Enables debugging mode: The parent process runs in the fore‐
201 ground with a CLI connection on stdin/stdout, and the child
202 process must be started explicitly with a CLI command. Terminat‐
203 ing the parent process will also terminate the child.
204
205 Only one of -d or -F can be specified, and -d cannot be used
206 together with -C.
207
208 -C Print VCL code compiled to C language and exit. Specify the VCL
209 file to compile with the -f option. Either -f or -b must be used
210 with -C, and -C cannot be used with -F or -d.
211
212 -V Display the version number and exit. This must be the only
213 option.
214
215 -h <type[,options]>
216 Specifies the hash algorithm. See Hash Algorithm section for a
217 list of supported algorithms.
218
219 -W waiter
220 Specifies the waiter type to use.
221
222 Hash Algorithm
223 The following hash algorithms are available:
224
225 -h critbit
226 self-scaling tree structure. The default hash algorithm in Var‐
227 nish Cache 2.1 and onwards. In comparison to a more traditional
228 B tree the critbit tree is almost completely lockless. Do not
229 change this unless you are certain what you're doing.
230
231 -h simple_list
232 A simple doubly-linked list. Not recommended for production
233 use.
234
235 -h <classic[,buckets]>
236 A standard hash table. The hash key is the CRC32 of the object's
237 URL modulo the size of the hash table. Each table entry points
238 to a list of elements which share the same hash key. The buckets
239 parameter specifies the number of entries in the hash table.
240 The default is 16383.
241
242 Storage Backend
243 The following storage types are available:
244
245 -s <default[,size]>
246 The default storage type resolves to umem where available and
247 malloc otherwise.
248
249 -s <malloc[,size]>
250 malloc is a memory based backend.
251
252 -s <umem[,size]>
253 umem is a storage backend which is more efficient than malloc on
254 platforms where it is available.
255
256 See the section on umem in chapter Storage backends of The Var‐
257 nish Users Guide for details.
258
259 -s <file,path[,size[,granularity[,advice]]]>
260 The file backend stores data in a file on disk. The file will be
261 accessed using mmap. Note that this storage provide no cache
262 persistence.
263
264 The path is mandatory. If path points to a directory, a tempo‐
265 rary file will be created in that directory and immediately
266 unlinked. If path points to a non-existing file, the file will
267 be created.
268
269 If size is omitted, and path points to an existing file with a
270 size greater than zero, the size of that file will be used. If
271 not, an error is reported.
272
273 Granularity sets the allocation block size. Defaults to the sys‐
274 tem page size or the filesystem block size, whichever is larger.
275
276 Advice tells the kernel how varnishd expects to use this mapped
277 region so that the kernel can choose the appropriate read-ahead
278 and caching techniques. Possible values are normal, random and
279 sequential, corresponding to MADV_NORMAL, MADV_RANDOM and
280 MADV_SEQUENTIAL madvise() advice argument, respectively.
281 Defaults to random.
282
283 -s <persistent,path,size>
284 Persistent storage. Varnish will store objects in a file in a
285 manner that will secure the survival of most of the objects in
286 the event of a planned or unplanned shutdown of Varnish. The
287 persistent storage backend has multiple issues with it and will
288 likely be removed from a future version of Varnish.
289
290 You can also prefix the type with NAME= to explicitly name a storage:
291
292 -s myStorage=malloc,5G
293
294 This allows to address it more easily in VCL:
295
296 set beresp.storage = storage.myStorage;
297
298 If the name is omitted, Varnish will name storages sN, starting with s0
299 and incrementing N for every new storage.
300
301 Jail
302 Varnish jails are a generalization over various platform specific meth‐
303 ods to reduce the privileges of varnish processes. They may have spe‐
304 cific options. Available jails are:
305
306 -j solaris
307 Reduce privileges(5) for varnishd and sub-process to the mini‐
308 mally required set. Only available on platforms which have the
309 setppriv(2) call.
310
311 -j <unix[,user=`user`][,ccgroup=`group`][,workuser=`user`]>
312 Default on all other platforms when varnishd is started with an
313 effective uid of 0 ("as root").
314
315 With the unix jail mechanism activated, varnish will switch to
316 an alternative user for subprocesses and change the effective
317 uid of the master process whenever possible.
318
319 The optional user argument specifies which alternative user to
320 use. It defaults to varnish.
321
322 The optional ccgroup argument specifies a group to add to var‐
323 nish subprocesses requiring access to a c-compiler. There is no
324 default.
325
326 The optional workuser argument specifies an alternative user to
327 use for the worker process. It defaults to vcache.
328
329 -j none
330 last resort jail choice: With jail mechanism none, varnish will
331 run all processes with the privileges it was started with.
332
333 Management Interface
334 If the -T option was specified, varnishd will offer a command-line man‐
335 agement interface on the specified address and port. The recommended
336 way of connecting to the command-line management interface is through
337 varnishadm(1).
338
339 The commands available are documented in varnish-cli(7).
340
341 CLI Command File
342 The -I option makes it possible to run arbitrary management commands
343 when varnishd is launched, before the worker process is started. In
344 particular, this is the way to load configurations, apply labels to
345 them, and make a VCL instance active that uses those labels on startup:
346
347 vcl.load panic /etc/varnish_panic.vcl
348 vcl.load siteA0 /etc/varnish_siteA.vcl
349 vcl.load siteB0 /etc/varnish_siteB.vcl
350 vcl.load siteC0 /etc/varnish_siteC.vcl
351 vcl.label siteA siteA0
352 vcl.label siteB siteB0
353 vcl.label siteC siteC0
354 vcl.load main /etc/varnish_main.vcl
355 vcl.use main
356
357 Every line in the file, including the last line, must be terminated by
358 a newline or carriage return.
359
360 If a command in the file is prefixed with '-', failure will not abort
361 the startup.
362
364 Run Time Parameter Flags
365 Runtime parameters are marked with shorthand flags to avoid repeating
366 the same text over and over in the table below. The meaning of the
367 flags are:
368
369 · experimental
370
371 We have no solid information about good/bad/optimal values for this
372 parameter. Feedback with experience and observations are most wel‐
373 come.
374
375 · delayed
376
377 This parameter can be changed on the fly, but will not take effect
378 immediately.
379
380 · restart
381
382 The worker process must be stopped and restarted, before this parame‐
383 ter takes effect.
384
385 · reload
386
387 The VCL programs must be reloaded for this parameter to take effect.
388
389 · experimental
390
391 We're not really sure about this parameter, tell us what you find.
392
393 · wizard
394
395 Do not touch unless you really know what you're doing.
396
397 · only_root
398
399 Only works if varnishd is running as root.
400
401 Default Value Exceptions on 32 bit Systems
402 Be aware that on 32 bit systems, certain default values are reduced
403 relative to the values listed below, in order to conserve VM space:
404
405 · workspace_client: 16k
406
407 · http_resp_size: 8k
408
409 · http_req_size: 12k
410
411 · gzip_stack_buffer: 4k
412
413 · thread_pool_stack: 64k
414
415 List of Parameters
416 This text is produced from the same text you will find in the CLI if
417 you use the param.show command:
418
419 accept_filter
420 NB: This parameter depends on a feature which is not available on all
421 platforms.
422
423 · Units: bool
424
425 · Default: off
426
427 · Flags:
428
429 Enable kernel accept-filters.
430
431 acceptor_sleep_decay
432 · Default: 0.9
433
434 · Minimum: 0
435
436 · Maximum: 1
437
438 · Flags: experimental
439
440 If we run out of resources, such as file descriptors or worker threads,
441 the acceptor will sleep between accepts. This parameter (multiplica‐
442 tively) reduce the sleep duration for each successful accept. (ie: 0.9
443 = reduce by 10%)
444
445 acceptor_sleep_incr
446 · Units: seconds
447
448 · Default: 0.000
449
450 · Minimum: 0.000
451
452 · Maximum: 1.000
453
454 · Flags: experimental
455
456 If we run out of resources, such as file descriptors or worker threads,
457 the acceptor will sleep between accepts. This parameter control how
458 much longer we sleep, each time we fail to accept a new connection.
459
460 acceptor_sleep_max
461 · Units: seconds
462
463 · Default: 0.050
464
465 · Minimum: 0.000
466
467 · Maximum: 10.000
468
469 · Flags: experimental
470
471 If we run out of resources, such as file descriptors or worker threads,
472 the acceptor will sleep between accepts. This parameter limits how
473 long it can sleep between attempts to accept new connections.
474
475 auto_restart
476 · Units: bool
477
478 · Default: on
479
480 Automatically restart the child/worker process if it dies.
481
482 backend_idle_timeout
483 · Units: seconds
484
485 · Default: 60.000
486
487 · Minimum: 1.000
488
489 Timeout before we close unused backend connections.
490
491 backend_local_error_holddown
492 · Units: seconds
493
494 · Default: 10.000
495
496 · Minimum: 0.000
497
498 · Flags: experimental
499
500 When connecting to backends, certain error codes (EADDRNOTAVAIL, EAC‐
501 CESS, EPERM) signal a local resource shortage or configuration issue
502 for which retrying connection attempts may worsen the situation due to
503 the complexity of the operations involved in the kernel. This parame‐
504 ter prevents repeated connection attempts for the configured duration.
505
506 backend_remote_error_holddown
507 · Units: seconds
508
509 · Default: 0.250
510
511 · Minimum: 0.000
512
513 · Flags: experimental
514
515 When connecting to backends, certain error codes (ECONNREFUSED, ENETUN‐
516 REACH) signal fundamental connection issues such as the backend not
517 accepting connections or routing problems for which repeated connection
518 attempts are considered useless This parameter prevents repeated con‐
519 nection attempts for the configured duration.
520
521 ban_cutoff
522 · Units: bans
523
524 · Default: 0
525
526 · Minimum: 0
527
528 · Flags: experimental
529
530 Expurge long tail content from the cache to keep the number of bans
531 below this value. 0 disables.
532
533 When this parameter is set to a non-zero value, the ban lurker contin‐
534 ues to work the ban list as usual top to bottom, but when it reaches
535 the ban_cutoff-th ban, it treats all objects as if they matched a ban
536 and expurges them from cache. As actively used objects get tested
537 against the ban list at request time and thus are likely to be associ‐
538 ated with bans near the top of the ban list, with ban_cutoff, least
539 recently accessed objects (the "long tail") are removed.
540
541 This parameter is a safety net to avoid bad response times due to bans
542 being tested at lookup time. Setting a cutoff trades response time for
543 cache efficiency. The recommended value is proportional to
544 rate(bans_lurker_tests_tested) / n_objects while the ban lurker is
545 working, which is the number of bans the system can sustain. The addi‐
546 tional latency due to request ban testing is in the order of ban_cutoff
547 / rate(bans_lurker_tests_tested). For example, for
548 rate(bans_lurker_tests_tested) = 2M/s and a tolerable latency of 100ms,
549 a good value for ban_cutoff may be 200K.
550
551 ban_dups
552 · Units: bool
553
554 · Default: on
555
556 Eliminate older identical bans when a new ban is added. This saves CPU
557 cycles by not comparing objects to identical bans. This is a waste of
558 time if you have many bans which are never identical.
559
560 ban_lurker_age
561 · Units: seconds
562
563 · Default: 60.000
564
565 · Minimum: 0.000
566
567 The ban lurker will ignore bans until they are this old. When a ban is
568 added, the active traffic will be tested against it as part of object
569 lookup. Because many applications issue bans in bursts, this parameter
570 holds the ban-lurker off until the rush is over. This should be set to
571 the approximate time which a ban-burst takes.
572
573 ban_lurker_batch
574 · Default: 1000
575
576 · Minimum: 1
577
578 The ban lurker sleeps ${ban_lurker_sleep} after examining this many
579 objects. Use this to pace the ban-lurker if it eats too many
580 resources.
581
582 ban_lurker_holdoff
583 · Units: seconds
584
585 · Default: 0.010
586
587 · Minimum: 0.000
588
589 · Flags: experimental
590
591 How long the ban lurker sleeps when giving way to lookup due to lock
592 contention.
593
594 ban_lurker_sleep
595 · Units: seconds
596
597 · Default: 0.010
598
599 · Minimum: 0.000
600
601 How long the ban lurker sleeps after examining ${ban_lurker_batch}
602 objects. Use this to pace the ban-lurker if it eats too many
603 resources. A value of zero will disable the ban lurker entirely.
604
605 between_bytes_timeout
606 · Units: seconds
607
608 · Default: 60.000
609
610 · Minimum: 0.000
611
612 We only wait for this many seconds between bytes received from the
613 backend before giving up the fetch. A value of zero means never give
614 up. VCL values, per backend or per backend request take precedence.
615 This parameter does not apply to pipe'ed requests.
616
617 cc_command
618 · Default: exec clang -g -O2 -Wall -Werror -Wno-error=unused-result
619 t-Werror t-Wall t-Wno-format-y2k t-W t-Wstrict-prototypes t-Wmiss‐
620 ing-prototypes t-Wpointer-arith t-Wreturn-type t-Wcast-qual
621 t-Wwrite-strings t-Wswitch t-Wshadow t-Wunused-parameter
622 t-Wcast-align t-Wchar-subscripts t-Wnested-externs t-Wextra
623 t-Wno-sign-compare -fstack-protector -Wno-missing-field-initial‐
624 izers -pthread -fpic -shared -Wl,-x -o %o %s
625
626 · Flags: must_reload
627
628 Command used for compiling the C source code to a dlopen(3) loadable
629 object. Any occurrence of %s in the string will be replaced with the
630 source file name, and %o will be replaced with the output file name.
631
632 cli_limit
633 · Units: bytes
634
635 · Default: 48k
636
637 · Minimum: 128b
638
639 · Maximum: 99999999b
640
641 Maximum size of CLI response. If the response exceeds this limit, the
642 response code will be 201 instead of 200 and the last line will indi‐
643 cate the truncation.
644
645 cli_timeout
646 · Units: seconds
647
648 · Default: 60.000
649
650 · Minimum: 0.000
651
652 Timeout for the childs replies to CLI requests from the mgt_param.
653
654 clock_skew
655 · Units: seconds
656
657 · Default: 10
658
659 · Minimum: 0
660
661 How much clockskew we are willing to accept between the backend and our
662 own clock.
663
664 clock_step
665 · Units: seconds
666
667 · Default: 1.000
668
669 · Minimum: 0.000
670
671 How much observed clock step we are willing to accept before we panic.
672
673 connect_timeout
674 · Units: seconds
675
676 · Default: 3.500
677
678 · Minimum: 0.000
679
680 Default connection timeout for backend connections. We only try to con‐
681 nect to the backend for this many seconds before giving up. VCL can
682 override this default value for each backend and backend request.
683
684 critbit_cooloff
685 · Units: seconds
686
687 · Default: 180.000
688
689 · Minimum: 60.000
690
691 · Maximum: 254.000
692
693 · Flags: wizard
694
695 How long the critbit hasher keeps deleted objheads on the cooloff list.
696
697 debug
698 · Default: none
699
700 Enable/Disable various kinds of debugging.
701
702 none Disable all debugging
703
704 Use +/- prefix to set/reset individual bits:
705
706 req_state
707 VSL Request state engine
708
709 workspace
710 VSL Workspace operations
711
712 waiter VSL Waiter internals
713
714 waitinglist
715 VSL Waitinglist events
716
717 syncvsl
718 Make VSL synchronous
719
720 hashedge
721 Edge cases in Hash
722
723 vclrel Rapid VCL release
724
725 lurker VSL Ban lurker
726
727 esi_chop
728 Chop ESI fetch to bits
729
730 flush_head
731 Flush after http1 head
732
733 vtc_mode
734 Varnishtest Mode
735
736 witness
737 Emit WITNESS lock records
738
739 vsm_keep
740 Keep the VSM file on restart
741
742 drop_pools
743 Drop thread pools (testing)
744
745 slow_acceptor
746 Slow down Acceptor
747
748 h2_nocheck
749 Disable various H2 checks
750
751 vmod_so_keep
752 Keep copied VMOD libraries
753
754 processors
755 Fetch/Deliver processors
756
757 protocol
758 Protocol debugging
759
760 default_grace
761 · Units: seconds
762
763 · Default: 10.000
764
765 · Minimum: 0.000
766
767 · Flags: obj_sticky
768
769 Default grace period. We will deliver an object this long after it has
770 expired, provided another thread is attempting to get a new copy.
771
772 default_keep
773 · Units: seconds
774
775 · Default: 0.000
776
777 · Minimum: 0.000
778
779 · Flags: obj_sticky
780
781 Default keep period. We will keep a useless object around this long,
782 making it available for conditional backend fetches. That means that
783 the object will be removed from the cache at the end of ttl+grace+keep.
784
785 default_ttl
786 · Units: seconds
787
788 · Default: 120.000
789
790 · Minimum: 0.000
791
792 · Flags: obj_sticky
793
794 The TTL assigned to objects if neither the backend nor the VCL code
795 assigns one.
796
797 esi_iovs
798 · Units: struct iovec
799
800 · Default: 10
801
802 · Minimum: 3
803
804 · Maximum: 1024
805
806 · Flags: wizard
807
808 Number of io vectors to allocate on the thread workspace for ESI
809 requests.
810
811 feature
812 · Default: none
813
814 Enable/Disable various minor features.
815
816 none Disable all features.
817
818 Use +/- prefix to enable/disable individual feature:
819
820 short_panic
821 Short panic message.
822
823 wait_silo
824 Wait for persistent silo.
825
826 no_coredump
827 No coredumps.
828
829 esi_ignore_https
830 Treat HTTPS as HTTP in ESI:includes
831
832 esi_disable_xml_check
833 Don't check of body looks like XML
834
835 esi_ignore_other_elements
836 Ignore non-esi XML-elements
837
838 esi_remove_bom
839 Remove UTF-8 BOM
840
841 https_scheme
842 Also split https URIs
843
844 http2 Support HTTP/2 protocol
845
846 http_date_postel
847 Relax parsing of timestamps in HTTP headers
848
849 fetch_chunksize
850 · Units: bytes
851
852 · Default: 16k
853
854 · Minimum: 4k
855
856 · Flags: experimental
857
858 The default chunksize used by fetcher. This should be bigger than the
859 majority of objects with short TTLs. Internal limits in the stor‐
860 age_file module makes increases above 128kb a dubious idea.
861
862 fetch_maxchunksize
863 · Units: bytes
864
865 · Default: 0.25G
866
867 · Minimum: 64k
868
869 · Flags: experimental
870
871 The maximum chunksize we attempt to allocate from storage. Making this
872 too large may cause delays and storage fragmentation.
873
874 first_byte_timeout
875 · Units: seconds
876
877 · Default: 60.000
878
879 · Minimum: 0.000
880
881 Default timeout for receiving first byte from backend. We only wait for
882 this many seconds for the first byte before giving up. A value of 0
883 means it will never time out. VCL can override this default value for
884 each backend and backend request. This parameter does not apply to
885 pipe.
886
887 gzip_buffer
888 · Units: bytes
889
890 · Default: 32k
891
892 · Minimum: 2k
893
894 · Flags: experimental
895
896 Size of malloc buffer used for gzip processing. These buffers are used
897 for in-transit data, for instance gunzip'ed data being sent to a
898 client.Making this space to small results in more overhead, writes to
899 sockets etc, making it too big is probably just a waste of memory.
900
901 gzip_level
902 · Default: 6
903
904 · Minimum: 0
905
906 · Maximum: 9
907
908 Gzip compression level: 0=debug, 1=fast, 9=best
909
910 gzip_memlevel
911 · Default: 8
912
913 · Minimum: 1
914
915 · Maximum: 9
916
917 Gzip memory level 1=slow/least, 9=fast/most compression. Memory impact
918 is 1=1k, 2=2k, ... 9=256k.
919
920 h2_header_table_size
921 · Units: bytes
922
923 · Default: 4k
924
925 · Minimum: 0b
926
927 HTTP2 header table size. This is the size that will be used for the
928 HPACK dynamic decoding table.
929
930 h2_initial_window_size
931 · Units: bytes
932
933 · Default: 65535b
934
935 · Minimum: 0b
936
937 · Maximum: 2147483647b
938
939 HTTP2 initial flow control window size.
940
941 h2_max_concurrent_streams
942 · Units: streams
943
944 · Default: 100
945
946 · Minimum: 0
947
948 HTTP2 Maximum number of concurrent streams. This is the number of
949 requests that can be active at the same time for a single HTTP2 connec‐
950 tion.
951
952 h2_max_frame_size
953 · Units: bytes
954
955 · Default: 16k
956
957 · Minimum: 16k
958
959 · Maximum: 16777215b
960
961 HTTP2 maximum per frame payload size we are willing to accept.
962
963 h2_max_header_list_size
964 · Units: bytes
965
966 · Default: 2147483647b
967
968 · Minimum: 0b
969
970 HTTP2 maximum size of an uncompressed header list.
971
972 h2_rx_window_increment
973 · Units: bytes
974
975 · Default: 1M
976
977 · Minimum: 1M
978
979 · Maximum: 1G
980
981 · Flags: wizard
982
983 HTTP2 Receive Window Increments. How big credits we send in WIN‐
984 DOW_UPDATE frames Only affects incoming request bodies (ie: POST, PUT
985 etc.)
986
987 h2_rx_window_low_water
988 · Units: bytes
989
990 · Default: 10M
991
992 · Minimum: 65535b
993
994 · Maximum: 1G
995
996 · Flags: wizard
997
998 HTTP2 Receive Window low water mark. We try to keep the window at
999 least this big Only affects incoming request bodies (ie: POST, PUT
1000 etc.)
1001
1002 http_gzip_support
1003 · Units: bool
1004
1005 · Default: on
1006
1007 Enable gzip support. When enabled Varnish request compressed objects
1008 from the backend and store them compressed. If a client does not sup‐
1009 port gzip encoding Varnish will uncompress compressed objects on
1010 demand. Varnish will also rewrite the Accept-Encoding header of clients
1011 indicating support for gzip to:
1012 Accept-Encoding: gzip
1013
1014 Clients that do not support gzip will have their Accept-Encoding header
1015 removed. For more information on how gzip is implemented please see the
1016 chapter on gzip in the Varnish reference.
1017
1018 When gzip support is disabled the variables beresp.do_gzip and
1019 beresp.do_gunzip have no effect in VCL.
1020
1021 http_max_hdr
1022 · Units: header lines
1023
1024 · Default: 64
1025
1026 · Minimum: 32
1027
1028 · Maximum: 65535
1029
1030 Maximum number of HTTP header lines we allow in
1031 {req|resp|bereq|beresp}.http (obj.http is autosized to the exact number
1032 of headers). Cheap, ~20 bytes, in terms of workspace memory. Note
1033 that the first line occupies five header lines.
1034
1035 http_range_support
1036 · Units: bool
1037
1038 · Default: on
1039
1040 Enable support for HTTP Range headers.
1041
1042 http_req_hdr_len
1043 · Units: bytes
1044
1045 · Default: 8k
1046
1047 · Minimum: 40b
1048
1049 Maximum length of any HTTP client request header we will allow. The
1050 limit is inclusive its continuation lines.
1051
1052 http_req_size
1053 · Units: bytes
1054
1055 · Default: 32k
1056
1057 · Minimum: 0.25k
1058
1059 Maximum number of bytes of HTTP client request we will deal with. This
1060 is a limit on all bytes up to the double blank line which ends the HTTP
1061 request. The memory for the request is allocated from the client
1062 workspace (param: workspace_client) and this parameter limits how much
1063 of that the request is allowed to take up.
1064
1065 http_resp_hdr_len
1066 · Units: bytes
1067
1068 · Default: 8k
1069
1070 · Minimum: 40b
1071
1072 Maximum length of any HTTP backend response header we will allow. The
1073 limit is inclusive its continuation lines.
1074
1075 http_resp_size
1076 · Units: bytes
1077
1078 · Default: 32k
1079
1080 · Minimum: 0.25k
1081
1082 Maximum number of bytes of HTTP backend response we will deal with.
1083 This is a limit on all bytes up to the double blank line which ends the
1084 HTTP response. The memory for the response is allocated from the back‐
1085 end workspace (param: workspace_backend) and this parameter limits how
1086 much of that the response is allowed to take up.
1087
1088 idle_send_timeout
1089 · Units: seconds
1090
1091 · Default: 60.000
1092
1093 · Minimum: 0.000
1094
1095 · Flags: delayed
1096
1097 Send timeout for individual pieces of data on client connections. May
1098 get extended if 'send_timeout' applies.
1099
1100 When this timeout is hit, the session is closed.
1101
1102 See the man page for setsockopt(2) under SO_SNDTIMEO for more informa‐
1103 tion.
1104
1105 listen_depth
1106 · Units: connections
1107
1108 · Default: 1024
1109
1110 · Minimum: 0
1111
1112 · Flags: must_restart
1113
1114 Listen queue depth.
1115
1116 lru_interval
1117 · Units: seconds
1118
1119 · Default: 2.000
1120
1121 · Minimum: 0.000
1122
1123 · Flags: experimental
1124
1125 Grace period before object moves on LRU list. Objects are only moved
1126 to the front of the LRU list if they have not been moved there already
1127 inside this timeout period. This reduces the amount of lock operations
1128 necessary for LRU list access.
1129
1130 max_esi_depth
1131 · Units: levels
1132
1133 · Default: 5
1134
1135 · Minimum: 0
1136
1137 Maximum depth of esi:include processing.
1138
1139 max_restarts
1140 · Units: restarts
1141
1142 · Default: 4
1143
1144 · Minimum: 0
1145
1146 Upper limit on how many times a request can restart.
1147
1148 max_retries
1149 · Units: retries
1150
1151 · Default: 4
1152
1153 · Minimum: 0
1154
1155 Upper limit on how many times a backend fetch can retry.
1156
1157 max_vcl
1158 · Default: 100
1159
1160 · Minimum: 0
1161
1162 Threshold of loaded VCL programs. (VCL labels are not counted.)
1163 Parameter max_vcl_handling determines behaviour.
1164
1165 max_vcl_handling
1166 · Default: 1
1167
1168 · Minimum: 0
1169
1170 · Maximum: 2
1171
1172 Behaviour when attempting to exceed max_vcl loaded VCL.
1173
1174 · 0 - Ignore max_vcl parameter.
1175
1176 · 1 - Issue warning.
1177
1178 · 2 - Refuse loading VCLs.
1179
1180 nuke_limit
1181 · Units: allocations
1182
1183 · Default: 50
1184
1185 · Minimum: 0
1186
1187 · Flags: experimental
1188
1189 Maximum number of objects we attempt to nuke in order to make space for
1190 a object body.
1191
1192 pcre_match_limit
1193 · Default: 10000
1194
1195 · Minimum: 1
1196
1197 The limit for the number of calls to the internal match() function in
1198 pcre_exec().
1199
1200 (See: PCRE_EXTRA_MATCH_LIMIT in pcre docs.)
1201
1202 This parameter limits how much CPU time regular expression matching can
1203 soak up.
1204
1205 pcre_match_limit_recursion
1206 · Default: 20
1207
1208 · Minimum: 1
1209
1210 The recursion depth-limit for the internal match() function in a
1211 pcre_exec().
1212
1213 (See: PCRE_EXTRA_MATCH_LIMIT_RECURSION in pcre docs.)
1214
1215 This puts an upper limit on the amount of stack used by PCRE for cer‐
1216 tain classes of regular expressions.
1217
1218 We have set the default value low in order to prevent crashes, at the
1219 cost of possible regexp matching failures.
1220
1221 Matching failures will show up in the log as VCL_Error messages with
1222 regexp errors -27 or -21.
1223
1224 Testcase r01576 can be useful when tuning this parameter.
1225
1226 ping_interval
1227 · Units: seconds
1228
1229 · Default: 3
1230
1231 · Minimum: 0
1232
1233 · Flags: must_restart
1234
1235 Interval between pings from parent to child. Zero will disable pinging
1236 entirely, which makes it possible to attach a debugger to the child.
1237
1238 pipe_timeout
1239 · Units: seconds
1240
1241 · Default: 60.000
1242
1243 · Minimum: 0.000
1244
1245 Idle timeout for PIPE sessions. If nothing have been received in either
1246 direction for this many seconds, the session is closed.
1247
1248 pool_req
1249 · Default: 10,100,10
1250
1251 Parameters for per worker pool request memory pool. The three numbers
1252 are:
1253
1254 min_pool
1255 minimum size of free pool.
1256
1257 max_pool
1258 maximum size of free pool.
1259
1260 max_age
1261 max age of free element.
1262
1263 pool_sess
1264 · Default: 10,100,10
1265
1266 Parameters for per worker pool session memory pool. The three numbers
1267 are:
1268
1269 min_pool
1270 minimum size of free pool.
1271
1272 max_pool
1273 maximum size of free pool.
1274
1275 max_age
1276 max age of free element.
1277
1278 pool_vbo
1279 · Default: 10,100,10
1280
1281 Parameters for backend object fetch memory pool. The three numbers
1282 are:
1283
1284 min_pool
1285 minimum size of free pool.
1286
1287 max_pool
1288 maximum size of free pool.
1289
1290 max_age
1291 max age of free element.
1292
1293 prefer_ipv6
1294 · Units: bool
1295
1296 · Default: off
1297
1298 Prefer IPv6 address when connecting to backends which have both IPv4
1299 and IPv6 addresses.
1300
1301 rush_exponent
1302 · Units: requests per request
1303
1304 · Default: 3
1305
1306 · Minimum: 2
1307
1308 · Flags: experimental
1309
1310 How many parked request we start for each completed request on the
1311 object. NB: Even with the implict delay of delivery, this parameter
1312 controls an exponential increase in number of worker threads.
1313
1314 send_timeout
1315 · Units: seconds
1316
1317 · Default: 600.000
1318
1319 · Minimum: 0.000
1320
1321 · Flags: delayed
1322
1323 Total timeout for ordinary HTTP1 responses. Does not apply to some
1324 internally generated errors and pipe mode.
1325
1326 When 'idle_send_timeout' is hit while sending an HTTP1 response, the
1327 timeout is extended unless the total time already taken for sending the
1328 response in its entirety exceeds this many seconds.
1329
1330 When this timeout is hit, the session is closed
1331
1332 shm_reclen
1333 · Units: bytes
1334
1335 · Default: 255b
1336
1337 · Minimum: 16b
1338
1339 · Maximum: 4084
1340
1341 Old name for vsl_reclen, use that instead.
1342
1343 shortlived
1344 · Units: seconds
1345
1346 · Default: 10.000
1347
1348 · Minimum: 0.000
1349
1350 Objects created with (ttl+grace+keep) shorter than this are always put
1351 in transient storage.
1352
1353 sigsegv_handler
1354 · Units: bool
1355
1356 · Default: on
1357
1358 · Flags: must_restart
1359
1360 Install a signal handler which tries to dump debug information on seg‐
1361 mentation faults, bus errors and abort signals.
1362
1363 syslog_cli_traffic
1364 · Units: bool
1365
1366 · Default: on
1367
1368 Log all CLI traffic to syslog(LOG_INFO).
1369
1370 tcp_fastopen
1371 · Units: bool
1372
1373 · Default: off
1374
1375 · Flags: must_restart
1376
1377 Enable TCP Fast Open extension.
1378
1379 tcp_keepalive_intvl
1380 · Units: seconds
1381
1382 · Default: 75.000
1383
1384 · Minimum: 1.000
1385
1386 · Maximum: 100.000
1387
1388 · Flags: experimental
1389
1390 The number of seconds between TCP keep-alive probes. Ignored for Unix
1391 domain sockets.
1392
1393 tcp_keepalive_probes
1394 · Units: probes
1395
1396 · Default: 9
1397
1398 · Minimum: 1
1399
1400 · Maximum: 100
1401
1402 · Flags: experimental
1403
1404 The maximum number of TCP keep-alive probes to send before giving up
1405 and killing the connection if no response is obtained from the other
1406 end. Ignored for Unix domain sockets.
1407
1408 tcp_keepalive_time
1409 · Units: seconds
1410
1411 · Default: 7200.000
1412
1413 · Minimum: 1.000
1414
1415 · Maximum: 7200.000
1416
1417 · Flags: experimental
1418
1419 The number of seconds a connection needs to be idle before TCP begins
1420 sending out keep-alive probes. Ignored for Unix domain sockets.
1421
1422 thread_pool_add_delay
1423 · Units: seconds
1424
1425 · Default: 0.000
1426
1427 · Minimum: 0.000
1428
1429 · Flags: experimental
1430
1431 Wait at least this long after creating a thread.
1432
1433 Some (buggy) systems may need a short (sub-second) delay between creat‐
1434 ing threads. Set this to a few milliseconds if you see the
1435 'threads_failed' counter grow too much.
1436
1437 Setting this too high results in insufficient worker threads.
1438
1439 thread_pool_destroy_delay
1440 · Units: seconds
1441
1442 · Default: 1.000
1443
1444 · Minimum: 0.010
1445
1446 · Flags: delayed, experimental
1447
1448 Wait this long after destroying a thread.
1449
1450 This controls the decay of thread pools when idle(-ish).
1451
1452 thread_pool_fail_delay
1453 · Units: seconds
1454
1455 · Default: 0.200
1456
1457 · Minimum: 0.010
1458
1459 · Flags: experimental
1460
1461 Wait at least this long after a failed thread creation before trying to
1462 create another thread.
1463
1464 Failure to create a worker thread is often a sign that the end is
1465 near, because the process is running out of some resource. This delay
1466 tries to not rush the end on needlessly.
1467
1468 If thread creation failures are a problem, check that thread_pool_max
1469 is not too high.
1470
1471 It may also help to increase thread_pool_timeout and thread_pool_min,
1472 to reduce the rate at which treads are destroyed and later recreated.
1473
1474 thread_pool_max
1475 · Units: threads
1476
1477 · Default: 5000
1478
1479 · Minimum: 100
1480
1481 · Flags: delayed
1482
1483 The maximum number of worker threads in each pool. The minimum value
1484 depends on thread_pool_min.
1485
1486 Do not set this higher than you have to, since excess worker threads
1487 soak up RAM and CPU and generally just get in the way of getting work
1488 done.
1489
1490 thread_pool_min
1491 · Units: threads
1492
1493 · Default: 100
1494
1495 · Maximum: 5000
1496
1497 · Flags: delayed
1498
1499 The minimum number of worker threads in each pool. The maximum value
1500 depends on thread_pool_max.
1501
1502 Increasing this may help ramp up faster from low load situations or
1503 when threads have expired.
1504
1505 Minimum is 10 threads.
1506
1507 thread_pool_reserve
1508 · Units: threads
1509
1510 · Default: 0
1511
1512 · Maximum: 95
1513
1514 · Flags: delayed
1515
1516 The number of worker threads reserved for vital tasks in each pool.
1517
1518 Tasks may require other tasks to complete (for example, client requests
1519 may require backend requests). This reserve is to ensure that such
1520 tasks still get to run even under high load.
1521
1522 Increasing the reserve may help setups with a high number of backend
1523 requests at the expense of client performance. Setting it too high will
1524 waste resources by keeping threads unused.
1525
1526 Default is 0 to auto-tune (currently 5% of thread_pool_min). Minimum
1527 is 1 otherwise, maximum is 95% of thread_pool_min.
1528
1529 thread_pool_stack
1530 · Units: bytes
1531
1532 · Default: 48k
1533
1534 · Minimum: 16k
1535
1536 · Flags: delayed
1537
1538 Worker thread stack size. This will likely be rounded up to a multiple
1539 of 4k (or whatever the page_size might be) by the kernel.
1540
1541 The required stack size is primarily driven by the depth of the
1542 call-tree. The most common relevant determining factors in varnish core
1543 code are GZIP (un)compression, ESI processing and regular expression
1544 matches. VMODs may also require significant amounts of additional
1545 stack. The nesting depth of VCL subs is another factor, although typi‐
1546 cally not predominant.
1547
1548 The stack size is per thread, so the maximum total memory required for
1549 worker thread stacks is in the order of size = thread_pools x
1550 thread_pool_max x thread_pool_stack.
1551
1552 Thus, in particular for setups with many threads, keeping the stack
1553 size at a minimum helps reduce the amount of memory required by Var‐
1554 nish.
1555
1556 On the other hand, thread_pool_stack must be large enough under all
1557 circumstances, otherwise varnish will crash due to a stack overflow.
1558 Usually, a stack overflow manifests itself as a segmentation fault (aka
1559 segfault / SIGSEGV) with the faulting address being near the stack
1560 pointer (sp).
1561
1562 Unless stack usage can be reduced, thread_pool_stack must be increased
1563 when a stack overflow occurs. Setting it in 150%-200% increments is
1564 recommended until stack overflows cease to occur.
1565
1566 thread_pool_timeout
1567 · Units: seconds
1568
1569 · Default: 300.000
1570
1571 · Minimum: 10.000
1572
1573 · Flags: delayed, experimental
1574
1575 Thread idle threshold.
1576
1577 Threads in excess of thread_pool_min, which have been idle for at least
1578 this long, will be destroyed.
1579
1580 thread_pool_watchdog
1581 · Units: seconds
1582
1583 · Default: 10.000
1584
1585 · Minimum: 0.100
1586
1587 · Flags: experimental
1588
1589 Thread queue stuck watchdog.
1590
1591 If no queued work have been released for this long, the worker process
1592 panics itself.
1593
1594 thread_pools
1595 · Units: pools
1596
1597 · Default: 2
1598
1599 · Minimum: 1
1600
1601 · Maximum: 32
1602
1603 · Flags: delayed, experimental
1604
1605 Number of worker thread pools.
1606
1607 Increasing the number of worker pools decreases lock contention. Each
1608 worker pool also has a thread accepting new connections, so for very
1609 high rates of incoming new connections on systems with many cores,
1610 increasing the worker pools may be required.
1611
1612 Too many pools waste CPU and RAM resources, and more than one pool for
1613 each CPU is most likely detrimental to performance.
1614
1615 Can be increased on the fly, but decreases require a restart to take
1616 effect.
1617
1618 thread_queue_limit
1619 · Default: 20
1620
1621 · Minimum: 0
1622
1623 · Flags: experimental
1624
1625 Permitted request queue length per thread-pool.
1626
1627 This sets the number of requests we will queue, waiting for an avail‐
1628 able thread. Above this limit sessions will be dropped instead of
1629 queued.
1630
1631 thread_stats_rate
1632 · Units: requests
1633
1634 · Default: 10
1635
1636 · Minimum: 0
1637
1638 · Flags: experimental
1639
1640 Worker threads accumulate statistics, and dump these into the global
1641 stats counters if the lock is free when they finish a job
1642 (request/fetch etc.) This parameters defines the maximum number of
1643 jobs a worker thread may handle, before it is forced to dump its accu‐
1644 mulated stats into the global counters.
1645
1646 timeout_idle
1647 · Units: seconds
1648
1649 · Default: 5.000
1650
1651 · Minimum: 0.000
1652
1653 Idle timeout for client connections.
1654
1655 A connection is considered idle until we have received the full request
1656 headers.
1657
1658 This parameter is particularly relevant for HTTP1 keepalive connec‐
1659 tions which are closed unless the next request is received before this
1660 timeout is reached.
1661
1662 timeout_linger
1663 · Units: seconds
1664
1665 · Default: 0.050
1666
1667 · Minimum: 0.000
1668
1669 · Flags: experimental
1670
1671 How long the worker thread lingers on an idle session before handing it
1672 over to the waiter. When sessions are reused, as much as half of all
1673 reuses happen within the first 100 msec of the previous request com‐
1674 pleting. Setting this too high results in worker threads not doing
1675 anything for their keep, setting it too low just means that more ses‐
1676 sions take a detour around the waiter.
1677
1678 vcc_allow_inline_c
1679 · Units: bool
1680
1681 · Default: off
1682
1683 Allow inline C code in VCL.
1684
1685 vcc_err_unref
1686 · Units: bool
1687
1688 · Default: on
1689
1690 Unreferenced VCL objects result in error.
1691
1692 vcc_unsafe_path
1693 · Units: bool
1694
1695 · Default: on
1696
1697 Allow '/' in vmod & include paths. Allow 'import ... from ...'.
1698
1699 vcl_cooldown
1700 · Units: seconds
1701
1702 · Default: 600.000
1703
1704 · Minimum: 0.000
1705
1706 How long a VCL is kept warm after being replaced as the active VCL
1707 (granularity approximately 30 seconds).
1708
1709 vcl_dir
1710 · Default: /opt/varnish/etc/varnish:/opt/varnish/share/varnish/vcl
1711
1712 Old name for vcl_path, use that instead.
1713
1714 vcl_path
1715 · Default: /opt/varnish/etc/varnish:/opt/varnish/share/varnish/vcl
1716
1717 Directory (or colon separated list of directories) from which relative
1718 VCL filenames (vcl.load and include) are to be found. By default Var‐
1719 nish searches VCL files in both the system configuration and shared
1720 data directories to allow packages to drop their VCL files in a stan‐
1721 dard location where relative includes would work.
1722
1723 vmod_dir
1724 · Default: /opt/varnish/lib/varnish/vmods
1725
1726 Old name for vmod_path, use that instead.
1727
1728 vmod_path
1729 · Default: /opt/varnish/lib/varnish/vmods
1730
1731 Directory (or colon separated list of directories) where VMODs are to
1732 be found.
1733
1734 vsl_buffer
1735 · Units: bytes
1736
1737 · Default: 4k
1738
1739 · Minimum: 267
1740
1741 Bytes of (req-/backend-)workspace dedicated to buffering VSL records.
1742 When this parameter is adjusted, most likely workspace_client and
1743 workspace_backend will have to be adjusted by the same amount.
1744
1745 Setting this too high costs memory, setting it too low will cause more
1746 VSL flushes and likely increase lock-contention on the VSL mutex.
1747
1748 The minimum tracks the vsl_reclen parameter + 12 bytes.
1749
1750 vsl_mask
1751 · Default: -ObjProtocol,-ObjStatus,-ObjReason,-Obj‐
1752 Header,-VCL_trace,-Work‐
1753 Thread,-Hash,-VfpAcct,-H2RxHdr,-H2RxBody,-H2TxHdr,-H2TxBody
1754
1755 Mask individual VSL messages from being logged.
1756
1757 default
1758 Set default value
1759
1760 Use +/- prefix in front of VSL tag name, to mask/unmask individual VSL
1761 messages.
1762
1763 vsl_reclen
1764 · Units: bytes
1765
1766 · Default: 255b
1767
1768 · Minimum: 16b
1769
1770 · Maximum: 4084b
1771
1772 Maximum number of bytes in SHM log record.
1773
1774 The maximum tracks the vsl_buffer parameter - 12 bytes.
1775
1776 vsl_space
1777 · Units: bytes
1778
1779 · Default: 80M
1780
1781 · Minimum: 1M
1782
1783 · Maximum: 4G
1784
1785 · Flags: must_restart
1786
1787 The amount of space to allocate for the VSL fifo buffer in the VSM mem‐
1788 ory segment. If you make this too small, varnish{ncsa|log} etc will
1789 not be able to keep up. Making it too large just costs memory
1790 resources.
1791
1792 vsm_free_cooldown
1793 · Units: seconds
1794
1795 · Default: 60.000
1796
1797 · Minimum: 10.000
1798
1799 · Maximum: 600.000
1800
1801 How long VSM memory is kept warm after a deallocation (granularity
1802 approximately 2 seconds).
1803
1804 vsm_space
1805 · Units: bytes
1806
1807 · Default: 1M
1808
1809 · Minimum: 1M
1810
1811 · Maximum: 1G
1812
1813 DEPRECATED: This parameter is ignored. There is no global limit on
1814 amount of shared memory now.
1815
1816 workspace_backend
1817 · Units: bytes
1818
1819 · Default: 64k
1820
1821 · Minimum: 1k
1822
1823 · Flags: delayed
1824
1825 Bytes of HTTP protocol workspace for backend HTTP req/resp. If larger
1826 than 4k, use a multiple of 4k for VM efficiency.
1827
1828 workspace_client
1829 · Units: bytes
1830
1831 · Default: 64k
1832
1833 · Minimum: 9k
1834
1835 · Flags: delayed
1836
1837 Bytes of HTTP protocol workspace for clients HTTP req/resp. Use a mul‐
1838 tiple of 4k for VM efficiency. For HTTP/2 compliance this must be at
1839 least 20k, in order to receive fullsize (=16k) frames from the client.
1840 That usually happens only in POST/PUT bodies. For other traffic-pat‐
1841 terns smaller values work just fine.
1842
1843 workspace_session
1844 · Units: bytes
1845
1846 · Default: 0.50k
1847
1848 · Minimum: 0.25k
1849
1850 · Flags: delayed
1851
1852 Allocation size for session structure and workspace. The workspace
1853 is primarily used for TCP connection addresses. If larger than 4k, use
1854 a multiple of 4k for VM efficiency.
1855
1856 workspace_thread
1857 · Units: bytes
1858
1859 · Default: 2k
1860
1861 · Minimum: 0.25k
1862
1863 · Maximum: 8k
1864
1865 · Flags: delayed
1866
1867 Bytes of auxiliary workspace per thread. This workspace is used for
1868 certain temporary data structures during the operation of a worker
1869 thread. One use is for the IO-vectors used during delivery. Setting
1870 this parameter too low may increase the number of writev() syscalls,
1871 setting it too high just wastes space. ~0.1k + UIO_MAXIOV *
1872 sizeof(struct iovec) (typically = ~16k for 64bit) is considered the
1873 maximum sensible value under any known circumstances (excluding exotic
1874 vmod use).
1875
1877 Varnish and bundled tools will, in most cases, exit with one of the
1878 following codes
1879
1880 · 0 OK
1881
1882 · 1 Some error which could be system-dependent and/or transient
1883
1884 · 2 Serious configuration / parameter error - retrying with the same
1885 configuration / parameters is most likely useless
1886
1887 The varnishd master process may also OR its exit code
1888
1889 · with 0x20 when the varnishd child process died,
1890
1891 · with 0x40 when the varnishd child process was terminated by a signal
1892 and
1893
1894 · with 0x80 when a core was dumped.
1895
1897 · varnishlog(1)
1898
1899 · varnishhist(1)
1900
1901 · varnishncsa(1)
1902
1903 · varnishstat(1)
1904
1905 · varnishtop(1)
1906
1907 · varnish-cli(7)
1908
1909 · vcl(7)
1910
1912 The varnishd daemon was developed by Poul-Henning Kamp in cooperation
1913 with Verdens Gang AS and Varnish Software.
1914
1915 This manual page was written by Dag-Erling Smørgrav with updates by
1916 Stig Sandbeck Mathisen <ssm@debian.org>, Nils Goroll and others.
1917
1919 This document is licensed under the same licence as Varnish itself. See
1920 LICENCE for details.
1921
1922 · Copyright (c) 2007-2015 Varnish Software AS
1923
1924
1925
1926
1927 VARNISHD(1)