Provided by: varnish_6.6.1-1ubuntu0.2_amd64 bug

NAME

       VCL-Variables - The complete album

DESCRIPTION

       This is a list of all variables in the VCL language.

       Variable names take the form scope.variable[.index], for instance:

          req.url
          beresp.http.date
          client.ip

       Which  operations  are  possible  on  each  variable  is  described  below, often with the
       shorthand "backend" which covers the  vcl_backend_*  {}  subroutines  and  "client"  which
       covers the rest, except vcl_init {} and vcl_fini {}.

   local, server, remote and client
       These variables describe the network connection between the client and varnishd.

       Without PROXY protocol:

               client    server
               remote    local
                 v          v
          CLIENT ------------ VARNISHD

       With PROXY protocol:

               client    server   remote     local
                 v          v       v          v
          CLIENT ------------ PROXY ------------ VARNISHD

       local.ip
          Type: IP

          Readable from: client, backend

          The  IP  address (and port number) of the local end of the TCP connection, for instance
          192.168.1.1:81

          If the connection is a UNIX domain socket, the value will be 0.0.0.0:0

       local.endpoint  VCL >= 4.1
          Type: STRING

          Readable from: client, backend

          The address of the '-a' socket the session was accepted on.

          If the argument was -a foo=:81 this would be ":81"

       local.socket    VCL >= 4.1
          Type: STRING

          Readable from: client, backend

          The name of the '-a' socket the session was accepted on.

          If the argument was -a foo=:81 this would be "foo".

          Note that all '-a' gets a default name on the form a%d if no name is provided.

       remote.ip
          Type: IP

          Readable from: client, backend

          The IP address of the other end of the TCP connection.  This can either be the  clients
          IP, or the outgoing IP of a proxy server.

          If the connection is a UNIX domain socket, the value will be 0.0.0.0:0

       client.ip
          Type: IP

          Readable from: client, backend

          The  client's  IP address, either the same as remote.ip or what the PROXY protocol told
          us.

       client.identity
          Type: STRING

          Readable from: client, backend

          Writable from: client

          Identification of the client, used to load balance in the client director.  Defaults to
          client.ip

          This  variable can be overwritten with more precise information, for instance extracted
          from a Cookie: header.

       server.ip
          Type: IP

          Readable from: client, backend

          The IP address of the socket on which the client connection was  received,  either  the
          same as server.ip or what the PROXY protocol told us.

       server.hostname
          Type: STRING

          Readable from: all

          The host name of the server, as returned by the gethostname(3) system function.

       server.identity
          Type: STRING

          Readable from: all

          The identity of the server, as set by the -i parameter.

          If  an  -i  parameter  is  not passed to varnishd, the return value from gethostname(3)
          system function will be used.

   req and req_top
       These variables describe the present request, and  when  ESI:include  requests  are  being
       processed, req_top points to the request received from the client.

       req
          Type: HTTP

          Readable from: client

          The entire request HTTP data structure.  Mostly useful for passing to VMODs.

       req.method
          Type: STRING

          Readable from: client

          Writable from: client

          The request method (e.g. "GET", "HEAD", ...)

       req.hash
          Type: BLOB

          Readable from: vcl_hit, vcl_miss, vcl_pass, vcl_purge, vcl_deliver

          The  hash  key  of  this  request.  Mostly useful for passing to VMODs, but can also be
          useful for debugging hit/miss status.

       req.url
          Type: STRING

          Readable from: client

          Writable from: client

          The requested URL, for instance "/robots.txt".

       req.proto       VCL <= 4.0
          Type: STRING

          Readable from: client

          Writable from: client

          The HTTP protocol version used by the client, usually "HTTP/1.1" or "HTTP/2.0".

       req.proto       VCL >= 4.1
          Type: STRING

          Readable from: client

          The HTTP protocol version used by the client, usually "HTTP/1.1" or "HTTP/2.0".

       req.http.*
          Type: HEADER

          Readable from: client

          Writable from: client

          Unsetable from: client

          The headers of request, things like req.http.date.

          The RFCs allow multiple headers with the same name, and both set and unset will  remove
          all headers with the name given.

          The  header  name  *  is  a  VCL  symbol  and as such cannot, for example, start with a
          numeral. Custom VMODs exist for handling of such header names.

       req.restarts
          Type: INT

          Readable from: client

          A count of how many times this request has been restarted.

       req.storage
          Type: STEVEDORE

          Readable from: client

          Writable from: client

          The storage backend to use to save this request body.

       req.esi_level
          Type: INT

          Readable from: client

          A count of how many levels of ESI requests we're currently at.

       req.ttl
          Type: DURATION

          Readable from: client

          Writable from: client

          Upper limit on the object age for cache lookups to return hit.

       req.grace
          Type: DURATION

          Readable from: client

          Writable from: client

          Upper limit on the object grace.

          During lookup the minimum of req.grace and the object's stored grace value will be used
          as the object's grace.

       req.xid
          Type: STRING

          Readable from: client

          Unique ID of this request.

       req.esi VCL <= 4.0
          Type: BOOL

          Readable from: client

          Writable from: client

          Set  to  false  to  disable  ESI  processing  regardless of any value in beresp.do_esi.
          Defaults to true. This variable is replaced by resp.do_esi in VCL 4.1.

       req.can_gzip
          Type: BOOL

          Readable from: client

          True if the client provided gzip or x-gzip in the Accept-Encoding header.

       req.backend_hint
          Type: BACKEND

          Readable from: client

          Writable from: client

          Set bereq.backend to this if we attempt to fetch.  When set to a director, reading this
          variable  returns  an  actual  backend if the director has resolved immediately, or the
          director otherwise.  When used in string context, returns the name of the  director  or
          backend, respectively.

       req.hash_ignore_busy
          Type: BOOL

          Readable from: client

          Writable from: client

          Default: false.

          Ignore any busy object during cache lookup.

          You only want to do this when you have two server looking up content sideways from each
          other to avoid deadlocks.

       req.hash_always_miss
          Type: BOOL

          Readable from: client

          Writable from: client

          Default: false.

          Force a cache miss for this request, even if perfectly good matching objects are in the
          cache.

          This  is useful to force-update the cache without invalidating existing entries in case
          the fetch fails.

       req.is_hitmiss
          Type: BOOL

          Readable from: client

          If this request resulted in a hitmiss

       req.is_hitpass
          Type: BOOL

          Readable from: client

          If this request resulted in a hitpass

       req_top.method
          Type: STRING

          Readable from: client

          The request method of the top-level request in a tree of  ESI  requests.  (e.g.  "GET",
          "HEAD").  Identical to req.method in non-ESI requests.

       req_top.url
          Type: STRING

          Readable from: client

          The  requested  URL  of  the top-level request in a tree of ESI requests.  Identical to
          req.url in non-ESI requests.

       req_top.http.*
          Type: HEADER

          Readable from: client

          HTTP headers of the top-level  request  in  a  tree  of  ESI  requests.   Identical  to
          req.http. in non-ESI requests.

          See req.http.* for general notes.

       req_top.proto
          Type: STRING

          Readable from: client

          HTTP protocol version of the top-level request in a tree of ESI requests.  Identical to
          req.proto in non-ESI requests.

   bereq
       This is the request we send to the backend, it is built from the clients req.*  fields  by
       filtering  out  "per-hop" fields which should not be passed along (Connection:, Range: and
       similar).

       Slightly more fields are allowed through for pass` fetches than for  `miss`  fetches,  for
       instance ``Range.

       bereq
          Type: HTTP

          Readable from: backend

          The entire backend request HTTP data structure.  Mostly useful as argument to VMODs.

       bereq.xid
          Type: STRING

          Readable from: vcl_pipe, backend

          Unique ID of this request.

       bereq.retries
          Type: INT

          Readable from: backend

          A count of how many times this request has been retried.

       bereq.backend
          Type: BACKEND

          Readable from: vcl_pipe, backend

          Writable from: vcl_pipe, backend

          This  is  the  backend  or  director we attempt to fetch from.  When set to a director,
          reading  this  variable  returns  an  actual  backend  if  the  director  has  resolved
          immediately,  or the director otherwise.  When used in string context, returns the name
          of the director or backend, respectively.

       bereq.body
          Type: BODY

          Unsetable from: vcl_backend_fetch

          The request body.

          Unset will also remove bereq.http.Content-Length.

       bereq.hash
          Type: BLOB

          Readable from: vcl_pipe, backend

          The hash key of this request, a copy of req.hash.

       bereq.method
          Type: STRING

          Readable from: vcl_pipe, backend

          Writable from: vcl_pipe, backend

          The request type (e.g. "GET", "HEAD").

          Regular (non-pipe, non-pass) fetches are always "GET"

       bereq.url
          Type: STRING

          Readable from: vcl_pipe, backend

          Writable from: vcl_pipe, backend

          The requested URL, copied from req.url

       bereq.proto     VCL <= 4.0
          Type: STRING

          Readable from: vcl_pipe, backend

          Writable from: vcl_pipe, backend

          The HTTP protocol version, "HTTP/1.1" unless a pass or pipe request has  "HTTP/1.0"  in
          req.proto

       bereq.proto     VCL >= 4.1
          Type: STRING

          Readable from: vcl_pipe, backend

          The  HTTP  protocol version, "HTTP/1.1" unless a pass or pipe request has "HTTP/1.0" in
          req.proto

       bereq.http.*
          Type: HEADER

          Readable from: vcl_pipe, backend

          Writable from: vcl_pipe, backend

          Unsetable from: vcl_pipe, backend

          The headers to be sent to the backend.

          See req.http.* for general notes.

       bereq.uncacheable
          Type: BOOL

          Readable from: backend

          Indicates whether this request is uncacheable due to a pass in the client side or a hit
          on an hit-for-pass object.

       bereq.connect_timeout
          Type: DURATION

          Readable from: vcl_pipe, backend

          Writable from: vcl_pipe, backend

          Default:  .connect_timeout attribute from the backend_definition, which defaults to the
          connect_timeout parameter, see varnishd(1).

          The time in seconds to wait for a backend connection to be established.

       bereq.first_byte_timeout
          Type: DURATION

          Readable from: backend

          Writable from: backend

          Default: .first_byte_timeout attribute from the backend_definition, which  defaults  to
          the first_byte_timeout parameter, see varnishd(1).

          The  time  in  seconds  to  wait  getting  the  first  byte back from the backend.  Not
          available in pipe mode.

       bereq.between_bytes_timeout
          Type: DURATION

          Readable from: backend

          Writable from: backend

          Default: .between_bytes_timeout attribute from the backend_definition,  which  defaults
          to the between_bytes_timeout parameter, see varnishd(1).

          The time in seconds to wait between each received byte from the backend.  Not available
          in pipe mode.

       bereq.is_bgfetch
          Type: BOOL

          Readable from: backend

          True for fetches where the client got a hit on an object in grace, and this  fetch  was
          kicked of in the background to get a fresh copy.

       bereq.is_hitmiss
          Type: BOOL

          Readable from: backend

          If this backend request was caused by a hitmiss.

       bereq.is_hitpass
          Type: BOOL

          Readable from: backend

          If this backend request was caused by a hitpass.

   beresp
       The  response  received from the backend, one cache misses, the store object is built from
       beresp.

       beresp
          Type: HTTP

          Readable from: vcl_backend_response, vcl_backend_error

          The entire backend response HTTP data structure, useful as argument to VMOD functions.

       beresp.body
          Type: BODY

          Writable from: vcl_backend_error

          For producing a synthetic body.

       beresp.proto    VCL <= 4.0
          Type: STRING

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          The HTTP protocol version the backend replied with.

       beresp.proto    VCL >= 4.1
          Type: STRING

          Readable from: vcl_backend_response, vcl_backend_error

          The HTTP protocol version the backend replied with.

       beresp.status
          Type: INT

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          The HTTP status code returned by the server.

          More information in the HTTP response status section.

       beresp.reason
          Type: STRING

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          The HTTP status message returned by the server.

       beresp.http.*
          Type: HEADER

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          Unsetable from: vcl_backend_response, vcl_backend_error

          The HTTP headers returned from the server.

          See req.http.* for general notes.

       beresp.do_esi
          Type: BOOL

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          Default: false.

          Set it to true to parse the object for ESI directives.  Will only be honored if req.esi
          is true.

          It is a VCL error to use beresp.do_esi after setting beresp.filters.

       beresp.do_stream
          Type: BOOL

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          Default: true.

          Deliver the object to the client while fetching the whole object into varnish.

          For  uncacheable  objects,  storage  for  parts of the body which have been sent to the
          client may get freed early, depending on the storage engine used.

          This variable has no effect if do_esi is true or when the response body is empty.

       beresp.do_gzip
          Type: BOOL

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          Default: false.

          Set to true to gzip the object while storing it.

          If http_gzip_support is disabled, setting this variable has no effect.

          It is a VCL error to use beresp.do_gzip after setting beresp.filters.

       beresp.do_gunzip
          Type: BOOL

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          Default: false.

          Set to true to gunzip the object while storing it in the cache.

          If http_gzip_support is disabled, setting this variable has no effect.

          It is a VCL error to use beresp.do_gunzip after setting beresp.filters.

       beresp.was_304
          Type: BOOL

          Readable from: vcl_backend_response, vcl_backend_error

          When true this indicates that we got a 304 response to our conditional fetch  from  the
          backend and turned that into beresp.status = 200

       beresp.uncacheable
          Type: BOOL

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          Inherited from bereq.uncacheable, see there.

          Setting this variable makes the object uncacheable.

          This may may produce a hit-for-miss object in the cache.

          Clearing the variable has no effect and will log the warning "Ignoring attempt to reset
          beresp.uncacheable".

       beresp.ttl
          Type: DURATION

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          Default: Cache-Control s-maxage or max-age directives, or a  value  computed  from  the
          Expires header's deadline, or the default_ttl parameter.

          The object's remaining time to live, in seconds.

       beresp.age
          Type: DURATION

          Readable from: vcl_backend_response, vcl_backend_error

          Default: Age header, or zero.

          The age of the object.

       beresp.grace
          Type: DURATION

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          Default: Cache-Control stale-while-revalidate directive, or default_grace parameter.

          Set to a period to enable grace.

       beresp.keep
          Type: DURATION

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          Default: default_keep parameter.

          Set to a period to enable conditional backend requests.

          The keep time is cache lifetime in addition to the ttl.

          Objects  with  ttl  expired  but  with  keep time left may be used to issue conditional
          (If-Modified-Since / If-None-Match) requests to the backend to refresh them.

       beresp.backend
          Type: BACKEND

          Readable from: vcl_backend_response, vcl_backend_error

          This is the backend we fetched from.  If bereq.backend was set to a director, this will
          be  the  backend  selected  by  the director.  When used in string context, returns its
          name.

       beresp.backend.name
          Type: STRING

          Readable from: vcl_backend_response, vcl_backend_error

          Name of the backend this response was fetched from.  Same as beresp.backend.

       beresp.backend.ip       VCL <= 4.0
          Type: IP

          Readable from: vcl_backend_response

          IP of the backend this response was fetched from.

       beresp.storage
          Type: STEVEDORE

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          The storage backend to use to save this object.

       beresp.storage_hint     VCL <= 4.0
          Type: STRING

          Readable from: vcl_backend_response, vcl_backend_error

          Writable from: vcl_backend_response, vcl_backend_error

          Deprecated since varnish  5.1  and  discontinued  since  VCL  4.1  (varnish  6.0).  Use
          beresp.storage instead.

          Hint to Varnish that you want to save this object to a particular storage backend.

       beresp.filters
          Type: STRING

          Readable from: vcl_backend_response

          Writable from: vcl_backend_response

          List  of  Varnish Fetch Processor (VFP) filters the beresp.body will be pulled through.
          The order left to right signifies processing from backend to cache,  iow  the  leftmost
          filter  is  run  first  on  the body as received from the backend after decoding of any
          transfer encodings.

          VFP Filters change the body before going into the cache  and/or  being  handed  to  the
          client side, where it may get processed again by resp.filters.

          The following VFP filters exist in varnish-cache:

          • gzip: compress a body using gzip

          • testgunzip: Test if a body is valid gzip and refuse it otherwise

          • gunzip: Uncompress gzip content

          • esi: ESI-process plain text content

          • esi_gzip: Save gzipped snippets for efficient ESI-processing

            This  filter  enables  stitching  together  ESI  from individually gzipped fragments,
            saving processing power for re-compression on the client side at the expense of  some
            compression efficiency.

          Additional VFP filters are available from VMODs.

          By default, beresp.filters is constructed as follows:

          • gunzip gets added for gzipped content if beresp.do_gunzip or beresp.do_esi are true.

          • esi_gzip  gets added if beresp.do_esi is true together with beresp.do_gzip or content
            is already compressed.

          • esi gets added if beresp.do_esi is true

          • gzip gets added for uncompressed content if beresp.do_gzip is true

          • testgunzip gets added for compressed content if beresp.do_gunzip is false.

          After beresp.filters is set, using any of the beforementioned beresp.do_* switches is a
          VCL error.

   obj
       This is the object we found in cache.  It cannot be modified.

       obj.proto
          Type: STRING

          Readable from: vcl_hit

          The HTTP protocol version stored in the object.

       obj.status
          Type: INT

          Readable from: vcl_hit

          The HTTP status code stored in the object.

          More information in the HTTP response status section.

       obj.reason
          Type: STRING

          Readable from: vcl_hit

          The HTTP reason phrase stored in the object.

       obj.hits
          Type: INT

          Readable from: vcl_hit, vcl_deliver

          The count of cache-hits on this object.

          In vcl_deliver a value of 0 indicates a cache miss.

       obj.http.*
          Type: HEADER

          Readable from: vcl_hit

          The HTTP headers stored in the object.

          See req.http.* for general notes.

       obj.ttl
          Type: DURATION

          Readable from: vcl_hit, vcl_deliver

          The object's remaining time to live, in seconds.

       obj.age
          Type: DURATION

          Readable from: vcl_hit, vcl_deliver

          The age of the object.

       obj.grace
          Type: DURATION

          Readable from: vcl_hit, vcl_deliver

          The object's grace period in seconds.

       obj.keep
          Type: DURATION

          Readable from: vcl_hit, vcl_deliver

          The object's keep period in seconds.

       obj.uncacheable
          Type: BOOL

          Readable from: vcl_deliver

          Whether the object is uncacheable (pass, hit-for-pass or hit-for-miss).

       obj.storage
          Type: STEVEDORE

          Readable from: vcl_hit, vcl_deliver

          The storage backend where this object is stored.

       obj.can_esi
          Type: BOOL

          Readable from: vcl_hit, vcl_deliver

          If  the  object  can  be ESI processed, that is if setting resp.do_esi or adding esi to
          resp.filters in vcl_deliver {} would cause the response body to be ESI processed.

   resp
       This is the response we send to the client, it is built from  either  beresp  (pass/miss),
       obj (hits) or created from whole cloth (synth).

       With  the  exception of resp.body all resp.* variables available in both vcl_deliver{} and
       vcl_synth{} as a matter of symmetry.

       resp
          Type: HTTP

          Readable from: vcl_deliver, vcl_synth

          The entire response HTTP data structure, useful as argument to VMODs.

       resp.body
          Type: BODY

          Writable from: vcl_synth

          To produce a synthetic response body, for instance for errors.

       resp.proto      VCL <= 4.0
          Type: STRING

          Readable from: vcl_deliver, vcl_synth

          Writable from: vcl_deliver, vcl_synth

          The HTTP protocol version to use for the response.

       resp.proto      VCL >= 4.1
          Type: STRING

          Readable from: vcl_deliver, vcl_synth

          The HTTP protocol version to use for the response.

       resp.status
          Type: INT

          Readable from: vcl_deliver, vcl_synth

          Writable from: vcl_deliver, vcl_synth

          The HTTP status code that will be returned.

          More information in the HTTP response status section.

          resp.status 200 will get changed into 304 by core code  after  a  return(deliver)  from
          vcl_deliver for conditional requests to cached content if validation succeeds.

          For the validation, first req.http.If-None-Match is compared against resp.http.Etag. If
          they compare equal according to the rules for weak validation (see RFC7232), a  304  is
          sent.

          Secondly, req.http.If-Modified-Since is compared against resp.http.Last-Modified or, if
          it is unset, against the point in time when the object was last modified based  on  the
          Date  and  Age  headers received with the backend response which created the object. If
          the object has not been modified based on that comparison, a 304 is sent.

       resp.reason
          Type: STRING

          Readable from: vcl_deliver, vcl_synth

          Writable from: vcl_deliver, vcl_synth

          The HTTP status message that will be returned.

       resp.http.*
          Type: HEADER

          Readable from: vcl_deliver, vcl_synth

          Writable from: vcl_deliver, vcl_synth

          Unsetable from: vcl_deliver, vcl_synth

          The HTTP headers that will be returned.

          See req.http.* for general notes.

       resp.do_esi     VCL >= 4.1
          Type: BOOL

          Readable from: vcl_deliver, vcl_synth

          Writable from: vcl_deliver, vcl_synth

          Default: obj.can_esi

          This can be used to  selectively  disable  ESI  processing,  even  though  ESI  parsing
          happened during fetch.  This is useful when Varnish caches peer with each other.

          It is a VCL error to use resp.do_esi after setting resp.filters.

       resp.is_streaming
          Type: BOOL

          Readable from: vcl_deliver, vcl_synth

          Returns true when the response will be streamed while being fetched from the backend.

       resp.filters
          Type: STRING

          Readable from: vcl_deliver, vcl_synth

          Writable from: vcl_deliver, vcl_synth

          List of VDP filters the resp.body will be pushed through.

          Before  resp.filters  is  set,  the  value  read  will  be  the  default filter list as
          determined by varnish based on resp.do_esi and request headers.

          After resp.filters is set, changing any of the conditions which otherwise determine the
          filter  selection will have no effiect. Using resp.do_esi is an error once resp.filters
          is set.

   Special variables
       now
          Type: TIME

          Readable from: all

          The current time, in seconds since the UNIX epoch.

          When converted to STRING in expressions it returns a formatted timestamp like  Tue,  20
          Feb 2018 09:30:31 GMT

   sess
       A  session  corresponds  to  the  "conversation"  that  Varnish  has  with a single client
       connection, over which one or more request/response transactions may take  place.  It  may
       comprise the traffic over an HTTP/1 keep-alive connection, or the multiplexed traffic over
       an HTTP/2 connection.

       sess.xid        VCL >= 4.1
          Type: STRING

          Readable from: client, backend

          Unique ID of this session.

       sess.timeout_idle
          Type: DURATION

          Readable from: client

          Writable from: client

          Idle timeout for this session, defaults to the timeout_idle parameter, see varnishd(1)

       sess.timeout_linger
          Type: DURATION

          Readable from: client

          Writable from: client

          Linger timeout  for  this  session,  defaults  to  the  timeout_linger  parameter,  see
          varnishd(1)

       sess.send_timeout
          Type: DURATION

          Readable from: client

          Writable from: client

          Total timeout for ordinary HTTP1 responses, defaults to the send_timeout parameter, see
          varnishd(1)

       sess.idle_send_timeout
          Type: DURATION

          Readable from: client

          Writable from: client

          Send timeout for individual pieces of data  on  client  connections,  defaults  to  the
          idle_send_timeout parameter, see varnishd(1)

   storage
       storage.<name>.free_space
          Type: BYTES

          Readable from: client, backend

          Free space available in the named stevedore. Only available for the malloc stevedore.

       storage.<name>.used_space
          Type: BYTES

          Readable from: client, backend

          Used space in the named stevedore. Only available for the malloc stevedore.

       storage.<name>.happy
          Type: BOOL

          Readable from: client, backend

          Health status for the named stevedore. Not available in any of the current stevedores.

   HTTP response status
       A HTTP status code has 3 digits XYZ where X must be between 1 and 5 included.  Since it is
       not uncommon to see HTTP clients or servers relying on non-standard or even invalid status
       codes, Varnish can work with any status between 100 and 999.

       Within  VCL  code it is even possible to use status codes in the form VWXYZ as long as the
       overall value is lower than 65536, but only the XYZ part will be sent to  the  client,  by
       which time the X must also have become non-zero.

       The  VWXYZ  form  of  status codes can be communicate extra information in resp.status and
       beresp.status to return(synth(...)) and return(error(...)), to  indicate  which  synthetic
       content to produce:

          sub vcl_recv {
              if ([...]) {
                  return synth(12404);
              }
          }

          sub vcl_synth {
              if (resp.status == 12404) {
                  [...]       // this specific 404
              } else if (resp.status % 1000 == 404) {
                  [...]       // all other 404's
              }
          }

       The  obj.status  variable will inherit the VWXYZ form, but in a ban expresion only the XYZ
       part will be available. The VWXYZ form is strictly limited to VCL execution.

       Assigning an HTTP  standardized  code  to  resp.status  or  beresp.status  will  also  set
       resp.reason or beresp.reason  to the corresponding status message.

SEE ALSO

varnishd(1)vcl(7)

HISTORY

       VCL was developed by Poul-Henning Kamp in cooperation with Verdens Gang AS, Redpill Linpro
       and Varnish Software.  This manual page is written by Per Buer, Poul-Henning Kamp,  Martin
       Blix Grydeland, Kristian Lyngstøl, Lasse Karstensen and others.

COPYRIGHT

       This  document  is  licensed  under  the  same  license as Varnish itself. See LICENSE for
       details.

       • Copyright (c) 2006 Verdens Gang AS

       • Copyright (c) 2006-2021 Varnish Software AS

                                                                                 VCL-VARIABLES(7)