NAME

       TSHttpTxnMilestoneGet - get a specified milestone timer value for the current transaction

SYNOPSIS

          #include <ts/ts.h>

       TSReturnCode TSHttpTxnMilestoneGet(TSHttpTxn txnp, TSMilestonesType milestone, TSHRTime *time)

DESCRIPTION

       TSHttpTxnMilestoneGet()  will  fetch  a  specific  milestone  timer value for the transaction txnp. These
       timers are calculated during the lifetime of a transaction and  are  measured  in  nanoseconds  from  the
       beginning of the transaction. time is used a pointer to storage to update if the call is successful.

       enum TSMilestonesType
              An enumeration of the valid indices of transaction milestone data.

              enumerator TS_MILESTONE_SM_START
                     Transaction state machine is initialized.

              enumerator TS_MILESTONE_UA_BEGIN
                     The client connection is accepted.

              enumerator TS_MILESTONE_UA_READ_HEADER_DONE
                     The request header from the client has been read and parsed.

              enumerator TS_MILESTONE_CACHE_OPEN_READ_BEGIN
                     Initiate read of the cache.

              enumerator TS_MILESTONE_CACHE_OPEN_READ_END
                     Initial cache read has resolved.

              enumerator TS_MILESTONE_CACHE_OPEN_WRITE_BEGIN
                     Start open for cache write.

              enumerator TS_MILESTONE_CACHE_OPEN_WRITE_END
                     Cache has been opened for write.

              enumerator TS_MILESTONE_DNS_LOOKUP_BEGIN
                     Initiate host resolution in HostDB

              enumerator TS_MILESTONE_DNS_LOOKUP_END
                     Host resolution resolves.

              enumerator TS_MILESTONE_SERVER_FIRST_CONNECT
                     First time origin server connect attempted or shared session attached.

              enumerator TS_MILESTONE_SERVER_CONNECT
                     Most recent time origin server connect attempted or shared session attached.

              enumerator TS_MILESTONE_SERVER_CONNECT_END
                     More recent time a connection attempt was resolved.

              enumerator TS_MILESTONE_SERVER_BEGIN_WRITE
                     First byte is written to the origin server connection.

              enumerator TS_MILESTONE_SERVER_FIRST_READ
                     First byte is read from connection to origin server.

              enumerator TS_MILESTONE_SERVER_READ_HEADER_DONE
                     Origin server response has been read and parsed.

              enumerator TS_MILESTONE_UA_BEGIN_WRITE
                     The response header write to the client starts.

              enumerator TS_MILESTONE_SERVER_CLOSE
                     Last I/O activity on origin server connection.

              enumerator TS_MILESTONE_UA_CLOSE
                     Last I/O activity on the client socket, or connection abort.

              enumerator TS_MILESTONE_SM_FINISH
                     Transaction has finished, state machine final logging has started.

              enumerator TS_MILESTONE_PLUGIN_ACTIVE
                     Amount of time plugins were active (running plugin code).

              enumerator TS_MILESTONE_PLUGIN_TOTAL
                     Amount of time spent in or waiting for plugins.

              enumerator TS_MILESTONE_TLS_HANDSHAKE_START
                     Timestamp  when  the  server  starts  the  TLS  handshake.  0  if no handshake is performed
                     (connection reuse).

              enumerator TS_MILESTONE_TLS_HANDSHAKE_END
                     Timestamp when the server completes the TLS handshake.  0  if  no  handshake  is  performed
                     (connection reuse).

              enumerator TS_MILESTONE_LAST_ENTRY
                     A  pseudo  index  which is set to be one more than the last valid index. This is useful for
                     looping over the data.

       • The server connect times predate the transmission of the SYN packet. That is, before  a  connection  to
         the origin server is completed.

       • A  connection  attempt is resolved when no more connection related activity remains to be done, and the
         connection is either established or has failed.

       • TS_MILESTONE_UA_CLOSE and TS_MILESTONE_SERVER_CLOSE are updated continuously during  the  life  of  the
         transaction,  every time there is I/O activity. The updating stops when the corresponding connection is
         closed, leaving the last I/O time as the final value.

       • The cache OPEN milestones time only the initial setup, the open, not the full read or write.

       • TS_MILESTONE_PLUGIN_ACTIVE and TS_MILESTONE_PLUGIN_TOTAL are different from  the  other  milestones  as
         they  measure  elapsed  time, not event time. The value is the elapsed time plus TS_MILESTONE_SM_START.
         This was decided to be more convenient because then these milestones can be handled / displayed in  the
         same way as the other milestones, as offsets from TS_MILESTONE_SM_START.

         TS_MILESTONE_PLUGIN_ACTIVE  value  is  the  amount  of  time  the plugin was active, that is performing
         computation. TS_MILESTONE_PLUGIN_TOTAL is the wall time which includes any  time  the  transaction  was
         blocked  while  a  plugin was active. For instance if a plugin waits on an external event, that waiting
         time will be in TS_MILESTONE_PLUGIN_TOTAL but not in TS_MILESTONE_PLUGIN_ACTIVE.

RETURN VALUES

       TS_SUCCESS if successful and time was updated, otherwise TS_ERROR.

SEE ALSO

       TSAPI(3ts)

COPYRIGHT

       2025, dev@trafficserver.apache.org

9.2                                               May 22, 2025                        TSHTTPTXNMILESTONEGET(3ts)