vsl

VSL(7)                                                                  VSL(7)



NAME
       VSL - Varnish Shared Memory Logging

OVERVIEW
       This document describes the format and content of all the Varnish
       shared memory logging tags. These tags are used by the varnishlog(1),
       varnishtop(1), etc.  logging tools supplied with Varnish.

   VSL tags
       Backend - Backend selected
              Logged when a connection is selected for handling a backend
              request.

              The format is:

                 %d %s %s
                 |  |  |
                 |  |  +- Backend display name
                 |  +---- VCL name
                 +------- Connection file descriptor

                 NOTE: This tag is currently not in use in the Varnish log.
                 It is mentioned here to document legacy versions of the log,
                 or reserved for possible use in future versions.

       BackendClose - Backend connection closed
              Logged when a backend connection is closed.

              The format is:

                 %d %s [ %s ]
                 |  |    |
                 |  |    +- Optional reason
                 |  +------ Backend display name
                 +--------- Connection file descriptor

       BackendOpen - Backend connection opened
              Logged when a new backend connection is opened.

              The format is:

                 %d %s %s %s %s %s
                 |  |  |  |  |  |
                 |  |  |  |  |  +- Local port
                 |  |  |  |  +---- Local address
                 |  |  |  +------- Remote port
                 |  |  +---------- Remote address
                 |  +------------- Backend display name
                 +---------------- Connection file descriptor

       BackendReuse - Backend connection put up for reuse
              Logged when a backend connection is put up for reuse by a later
              connection.

              The format is:

                 %d %s
                 |  |
                 |  +- Backend display name
                 +---- Connection file descriptor

       BackendStart - Backend request start
              Start of backend processing. Logs the backend IP address and
              port number.

              The format is:

                 %s %s
                 |  |
                 |  +- Backend Port number
                 +---- Backend IP4/6 address

                 NOTE: This tag is currently not in use in the Varnish log.
                 It is mentioned here to document legacy versions of the log,
                 or reserved for possible use in future versions.

       Backend_health - Backend health check
              The result of a backend health probe.

              The format is:

                 %s %s %s %s %u %u %u %f %f %s
                 |  |  |  |  |  |  |  |  |  |
                 |  |  |  |  |  |  |  |  |  +- Probe HTTP response / error information
                 |  |  |  |  |  |  |  |  +---- Average response time
                 |  |  |  |  |  |  |  +------- Response time
                 |  |  |  |  |  |  +---------- Probe window size
                 |  |  |  |  |  +------------- Probe threshold level
                 |  |  |  |  +---------------- Number of good probes in window
                 |  |  |  +------------------- Probe window bits
                 |  |  +---------------------- "healthy" or "sick"
                 |  +------------------------- "Back", "Still" or "Went"
                 +---------------------------- Backend name

              Probe window bits are:

                 '4': Good IPv4
                 '6': Good IPv6
                 'U': Good UNIX
                 'x': Error Xmit
                 'X': Good Xmit
                 'r': Error Recv
                 'R': Good Recv
                 'H': Happy

       Begin - Marks the start of a VXID
              The first record of a VXID transaction.

              The format is:

                 %s %d %s
                 |  |  |
                 |  |  +- Reason
                 |  +---- Parent vxid
                 +------- Type ("sess", "req" or "bereq")

       BereqAcct - Backend request accounting
              Contains byte counters from backend request processing.

              The format is:

                 %d %d %d %d %d %d
                 |  |  |  |  |  |
                 |  |  |  |  |  +- Total bytes received
                 |  |  |  |  +---- Body bytes received
                 |  |  |  +------- Header bytes received
                 |  |  +---------- Total bytes transmitted
                 |  +------------- Body bytes transmitted
                 +---------------- Header bytes transmitted

       BereqHeader - Backend request header
              HTTP header contents.

              The format is:

                 %s: %s
                 |   |
                 |   +- Header value
                 +----- Header name

       BereqMethod - Backend request method
              The HTTP request method used.

       BereqProtocol - Backend request protocol
              The HTTP protocol version information.

       BereqURL - Backend request URL
              The HTTP request URL.

       BerespHeader - Backend response header
              HTTP header contents.

              The format is:

                 %s: %s
                 |   |
                 |   +- Header value
                 +----- Header name

       BerespProtocol - Backend response protocol
              The HTTP protocol version information.

       BerespReason - Backend response response
              The HTTP response string received.

       BerespStatus - Backend response status
              The HTTP status code received.

       BogoHeader - Bogus HTTP received
              Contains the first 20 characters of received HTTP headers we
              could not make sense of.  Applies to both req.http and
              beresp.http.

       CLI - CLI communication
              CLI communication between varnishd master and child process.

       Debug - Debug messages
              Debug messages can normally be ignored, but are sometimes
              helpful during trouble-shooting.  Most debug messages must be
              explicitly enabled with parameters.

              Debug messages may be added, changed or removed without prior
              notice and shouldn't be considered stable.

              NB: This log record is masked by default.

       ESI_xmlerror - ESI parser error or warning message
              An error or warning was generated during parsing of an ESI
              object. The log record describes the problem encountered.

       End - Marks the end of a VXID
              The last record of a VXID transaction.

       Error - Error messages
              Error messages are stuff you probably want to know.

       ExpBan - Object evicted due to ban
              Logs the VXID when an object is banned.

       ExpKill - Object expiry event
              Logs events related to object expiry. The events are:

              EXP_Rearm
                     Logged when the expiry time of an object changes.

              EXP_Inbox
                     Logged when the expiry thread picks an object from the
                     inbox for processing.

              EXP_Kill
                     Logged when the expiry thread kills an object from the
                     inbox.

              EXP_When
                     Logged when the expiry thread moves an object on the
                     binheap.

              EXP_Expired
                     Logged when the expiry thread expires an object.

              LRU_Cand
                     Logged when an object is evaluated for LRU force expiry.

              LRU    Logged when an object is force expired due to LRU.

              LRU_Fail
                     Logged when no suitable candidate object is found for LRU
                     force expiry.

              The format is:

                 EXP_Rearm p=%p E=%f e=%f f=0x%x
                 EXP_Inbox p=%p e=%f f=0x%x
                 EXP_Kill p=%p e=%f f=0x%x
                 EXP_When p=%p e=%f f=0x%x
                 EXP_Expired x=%u t=%f
                 LRU_Cand p=%p f=0x%x r=%d
                 LRU x=%u
                 LRU_Fail

                 Legend:
                 p=%p         Objcore pointer
                 t=%f         Remaining TTL (s)
                 e=%f         Expiry time (unix epoch)
                 E=%f         Old expiry time (unix epoch)
                 f=0x%x       Objcore flags
                 r=%d         Objcore refcount
                 x=%u         Object VXID

       FetchError - Error while fetching object
              Logs the error message of a failed fetch operation.

              Error messages should be self-explanatory, yet the http
              connection(HTC) class of errors is reported with these symbols:

                 • junk (-5): Received unexpected data

                 • close (-4): Connection closed

                 • timeout (-3): Timed out

                 • overflow (-2): Buffer/workspace too small

                 • eof (-1): Unexpected end of input

                 • empty (0): Empty response

                 • more (1): More data required

                 • complete (2): Data complete (no error)

                 • idle (3): Connection was closed while idle

              Notice that some HTC errors are never emitted.

       Fetch_Body - Body fetched from backend
              Ready to fetch body from backend.

              The format is:

                 %d (%s) %s
                 |   |    |
                 |   |    +---- 'stream' or '-'
                 |   +--------- Text description of body fetch mode
                 +------------- Body fetch mode

       Filters - Body filters
              List of filters applied to the body

       Gzip - G(un)zip performed on object
              A Gzip record is emitted for each instance of gzip or gunzip
              work performed. Worst case, an ESI transaction stored in gzip'ed
              objects but delivered gunziped, will run into many of these.

              The format is:

                 %c %c %c %d %d %d %d %d
                 |  |  |  |  |  |  |  |
                 |  |  |  |  |  |  |  +- Bit length of compressed data
                 |  |  |  |  |  |  +---- Bit location of 'last' bit
                 |  |  |  |  |  +------- Bit location of first deflate block
                 |  |  |  |  +---------- Bytes output
                 |  |  |  +------------- Bytes input
                 |  |  +---------------- 'E': ESI, '-': Plain object
                 |  +------------------- 'F': Fetch, 'D': Deliver
                 +---------------------- 'G': Gzip, 'U': Gunzip, 'u': Gunzip-test

              Examples:

                 U F E 182 159 80 80 1392
                 G F E 159 173 80 1304 1314

       H2RxBody - Received HTTP2 frame body
              Binary data

       H2RxHdr - Received HTTP2 frame header
              Binary data

       H2TxBody - Transmitted HTTP2 frame body
              Binary data

       H2TxHdr - Transmitted HTTP2 frame header
              Binary data

       Hash - Value added to hash
              This value was added to the object lookup hash.

              NB: This log record is masked by default.

       Hit - Hit object in cache
              Object looked up in cache.

              The format is:

                 %u %f %f %f
                 |  |  |  |
                 |  |  |  +- Keep period
                 |  |  +---- Grace period
                 |  +------- Remaining TTL
                 +---------- VXID of the object

       HitMiss - Hit for miss object in cache.
              Hit-for-miss object looked up in cache.

              The format is:

                 %u %f
                 |  |
                 |  +- Remaining TTL
                 +---- VXID of the object

       HitPass - Hit for pass object in cache.
              Hit-for-pass object looked up in cache.

              The format is:

                 %u %f
                 |  |
                 |  +- Remaining TTL
                 +---- VXID of the object

       HttpGarbage - Unparseable HTTP request
              Logs the content of unparseable HTTP requests.

       Length - Size of object body
              Logs the size of a fetch object body.

       Link - Links to a child VXID
              Links this VXID to any child VXID it initiates.

              The format is:

                 %s %d %s
                 |  |  |
                 |  |  +- Reason
                 |  +---- Child vxid
                 +------- Child type ("req" or "bereq")

       LostHeader - Failed attempt to set HTTP header
              Logs the header name of a failed HTTP header operation due to
              resource exhaustion or configured limits.

       ObjHeader - Object header
              HTTP header contents.

              The format is:

                 %s: %s
                 |   |
                 |   +- Header value
                 +----- Header name

       ObjProtocol - Object protocol
              The HTTP protocol version information.

       ObjReason - Object response
              The HTTP response string received.

       ObjStatus - Object status
              The HTTP status code received.

       PipeAcct - Pipe byte counts
              Contains byte counters for pipe sessions.

              The format is:

                 %d %d %d %d
                 |  |  |  |
                 |  |  |  +------- Piped bytes to client
                 |  |  +---------- Piped bytes from client
                 |  +------------- Backend request headers
                 +---------------- Client request headers

       Proxy - PROXY protocol information
              PROXY protocol information.

              The format is:

                 %d %s %d %s %d
                 |  |  |  |  |
                 |  |  |  |  +- server port
                 |  |  |  +---- server ip
                 |  |  +------- client port
                 |  +---------- client ip
                 +------------- PROXY protocol version

                 All fields are "local" for PROXY local connections (command 0x0)

       ProxyGarbage - Unparseable PROXY request
              A PROXY protocol header was unparseable.

       ReqAcct - Request handling byte counts
              Contains byte counts for the request handling.  The body bytes
              count includes transmission overhead (ie: chunked encoding).
              ESI sub-requests show the body bytes this ESI fragment including
              any subfragments contributed to the top level request.  The
              format is:

                 %d %d %d %d %d %d
                 |  |  |  |  |  |
                 |  |  |  |  |  +- Total bytes transmitted
                 |  |  |  |  +---- Body bytes transmitted
                 |  |  |  +------- Header bytes transmitted
                 |  |  +---------- Total bytes received
                 |  +------------- Body bytes received
                 +---------------- Header bytes received

       ReqHeader - Client request header
              HTTP header contents.

              The format is:

                 %s: %s
                 |   |
                 |   +- Header value
                 +----- Header name

       ReqMethod - Client request method
              The HTTP request method used.

       ReqProtocol - Client request protocol
              The HTTP protocol version information.

       ReqStart - Client request start
              Start of request processing. Logs the client address, port
              number  and listener endpoint name (from the -a command-line
              argument).

              The format is:

                 %s %s %s
                 |  |  |
                 |  |  +-- Listener name (from -a)
                 |  +----- Client Port number (0 for Unix domain sockets)
                 +-------- Client IP4/6 address (0.0.0.0 for UDS)

       ReqURL - Client request URL
              The HTTP request URL.

       RespHeader - Client response header
              HTTP header contents.

              The format is:

                 %s: %s
                 |   |
                 |   +- Header value
                 +----- Header name

       RespProtocol - Client response protocol
              The HTTP protocol version information.

       RespReason - Client response response
              The HTTP response string received.

       RespStatus - Client response status
              The HTTP status code received.

       SessClose - Client connection closed
              SessClose is the last record for any client connection.

              The format is:

                 %s %f
                 |  |
                 |  +- How long the session was open
                 +---- Why the connection closed

       SessError - Client connection accept failed
              Accepting a client connection has failed.

              The format is:

                 %s %s %s %d %d %s
                 |  |  |  |  |  |
                 |  |  |  |  |  +- Detailed error message
                 |  |  |  |  +---- Error Number (errno) from accept(2)
                 |  |  |  +------- File descriptor number
                 |  |  +---------- Local TCP port / 0 for UDS
                 |  +------------- Local IPv4/6 address / 0.0.0.0 for UDS
                 +---------------- Socket name (from -a argument)

       SessOpen - Client connection opened
              The first record for a client connection, with the
              socket-endpoints of the connection.

              The format is:

                 %s %d %s %s %s %d
                 |  |  |  |  |  |
                 |  |  |  |  |  +- File descriptor number
                 |  |  |  |  +---- Local TCP port / 0 for UDS
                 |  |  |  +------- Local IPv4/6 address / 0.0.0.0 for UDS
                 |  |  +---------- Socket name (from -a argument)
                 |  +------------- Remote TCP port / 0 for UDS
                 +---------------- Remote IPv4/6 address / 0.0.0.0 for UDS

       Storage - Where object is stored
              Type and name of the storage backend the object is stored in.

              The format is:

                 %s %s
                 |  |
                 |  +- Name of storage backend
                 +---- Type ("malloc", "file", "persistent" etc.)

       TTL - TTL set on object
              A TTL record is emitted whenever the ttl, grace or keep values
              for an object is set as well as whether the object is  cacheable
              or not.

              The format is:

                 %s %d %d %d %d [ %d %d %u %u ] %s
                 |  |  |  |  |    |  |  |  |    |
                 |  |  |  |  |    |  |  |  |    +- "cacheable" or "uncacheable"
                 |  |  |  |  |    |  |  |  +------ Max-Age from Cache-Control header
                 |  |  |  |  |    |  |  +--------- Expires header
                 |  |  |  |  |    |  +------------ Date header
                 |  |  |  |  |    +--------------- Age (incl Age: header value)
                 |  |  |  |  +-------------------- Reference time for TTL
                 |  |  |  +----------------------- Keep
                 |  |  +-------------------------- Grace
                 |  +----------------------------- TTL
                 +-------------------------------- "RFC", "VCL" or "HFP"

              The four optional fields are only present in "RFC" headers.

              Examples:

                 RFC 60 10 -1 1312966109 1312966109 1312966109 0 60 cacheable
                 VCL 120 10 0 1312966111 uncacheable
                 HFP 2 0 0 1312966113 uncacheable

       Timestamp - Timing information
              Contains timing information for the Varnish worker threads.

              Time stamps are issued by Varnish on certain events, and show
              the absolute time of the event, the time spent since the start
              of the work unit, and the time spent since the last timestamp
              was logged. See the TIMESTAMPS section below for information
              about the individual time stamps.

              The format is:

                 %s: %f %f %f
                 |   |  |  |
                 |   |  |  +- Time since last timestamp
                 |   |  +---- Time since start of work unit
                 |   +------- Absolute time of event
                 +----------- Event label

       VCL_Error - VCL execution error message
              Logs error messages generated during VCL execution.

       VCL_Log - Log statement from VCL
              User generated log messages insert from VCL through std.log()

       VCL_acl - VCL ACL check results
              Logs VCL ACL evaluation results.

       VCL_call - VCL method called
              Logs the VCL method name when a VCL method is called.

       VCL_return - VCL method return value
              Logs the VCL method terminating statement.

       VCL_trace - VCL trace data
              Logs VCL execution trace data.

              The format is:

                 %s %u %u.%u.%u
                 |  |  |  |  |
                 |  |  |  |  +- VCL program line position
                 |  |  |  +---- VCL program line number
                 |  |  +------- VCL program source index
                 |  +---------- VCL trace point index
                 +------------- VCL configname

              NB: This log record is masked by default.

       VCL_use - VCL in use
              Records the name of the VCL being used.

              The format is:

                 %s [ %s %s ]
                 |    |  |
                 |    |  +- Name of label used to find it
                 |    +---- "via"
                 +--------- Name of VCL put in use

       VSL - VSL API warnings and error message
              Warnings and error messages generated by the VSL API while
              reading the shared memory log.

       VfpAcct - Fetch filter accounting
              Contains name of VFP and statistics.

              The format is:

                 %s %d %d
                 |  |  |
                 |  |  +- Total bytes produced
                 |  +---- Number of calls made
                 +------- Name of filter

              NB: This log record is masked by default.

       Witness - Lock order witness records
              Diagnostic recording of locking order.

       WorkThread - Logs thread start/stop events
              Logs worker thread creation and termination events.

              The format is:

                 %p %s
                 |  |
                 |  +- [start|end]
                 +---- Worker struct pointer

              NB: This log record is masked by default.

TIMESTAMPS
       Timestamps are inserted in the log on completing certain events during
       the worker thread's task handling. The timestamps has a label showing
       which event was completed. The reported fields show the absolute time
       of the event, the time spent since the start of the task and the time
       spent since the last timestamp was logged.

       The timestamps logged automatically by Varnish are inserted after
       completing events that are expected to have delays (e.g. network IO or
       spending time on a waitinglist). Timestamps can also be inserted from
       VCL using the std.timestamp() method. If one is doing time consuming
       tasks in the VCL configuration, it's a good idea to log a timestamp
       after completing that task. This keeps the timing information in
       subsequent timestamps from including the time spent on the VCL event.

   Request handling timestamps
       Start  The start of request processing (first byte received or
              restart).

       Req    Complete client request received.

       ReqBody
              Client request body processed (discarded, cached or passed to
              the backend).

       Waitinglist
              Came off waitinglist.

       Fetch  Fetch processing finished (completely fetched or ready for
              streaming).

       Process
              Processing finished, ready to deliver the client response.

       Resp   Delivery of response to the client finished.

       Restart
              Client request is being restarted.

   Pipe handling timestamps
       Pipe   Opened a pipe to the backend and forwarded the request.

       PipeSess
              The pipe session has finished.

   Backend fetch timestamps
       Start  Start of the backend fetch processing.

       Bereq  Backend request sent.

       Beresp Backend response headers received.

       BerespBody
              Backend response body received.

       Retry  Backend request is being retried.

       Error  Backend request failed to vcl_backend_error.

HISTORY
       This document was initially written by Poul-Henning Kamp, and later
       updated by Martin Blix Grydeland.

SEE ALSOvarnishhist(1)varnishlog(1)varnishncsa(1)varnishtop(1)

COPYRIGHT
       This document is licensed under the same licence as Varnish itself. See
       LICENCE for details.

       • Copyright (c) 2006 Verdens Gang AS

       • Copyright (c) 2006-2015 Varnish Software AS



                                                                        VSL(7)