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DBI::Gofer::Execute(3)User Contributed Perl DocumentatioDBI::Gofer::Execute(3)

NAME
       DBI::Gofer::Execute - Executes Gofer requests and returns Gofer
       responses
SYNOPSIS
         $executor = DBI::Gofer::Execute->new( { ...config... });
         $response = $executor->execute_request( $request );
DESCRIPTION
       Accepts a DBI::Gofer::Request object, executes the requested DBI method
       calls, and returns a DBI::Gofer::Response object.
       Any error, including any internal 'fatal' errors are caught and
       converted into a DBI::Gofer::Response object.
       This module is usually invoked by a 'server-side' Gofer transport
       module.  They usually have names in the ""DBI::Gofer::Transport::*""
       namespace.  Examples include: DBI::Gofer::Transport::stream and
       DBI::Gofer::Transport::mod_perl.
CONFIGURATION
   check_request_sub
       If defined, it must be a reference to a subroutine that will 'check'
       the request.  It is passed the request object and the executor as its
       only arguments.
       The subroutine can either return the original request object or die
       with a suitable error message (which will be turned into a Gofer
       response).
       It can also construct and return a new request that should be executed
       instead of the original request.
   check_response_sub
       If defined, it must be a reference to a subroutine that will 'check'
       the response.  It is passed the response object, the executor, and the
       request object.  The sub may alter the response object and return
       undef, or return a new response object.
       This mechanism can be used to, for example, terminate the service if
       specific database errors are seen.
   forced_connect_dsn
       If set, this DSN is always used instead of the one in the request.
   default_connect_dsn
       If set, this DSN is used if "forced_connect_dsn" is not set and the
       request does not contain a DSN itself.
   forced_connect_attributes
       A reference to a hash of connect() attributes. Individual attributes in
       "forced_connect_attributes" will take precedence over corresponding
       attributes in the request.
   default_connect_attributes
       A reference to a hash of connect() attributes. Individual attributes in
       the request take precedence over corresponding attributes in
       "default_connect_attributes".
   max_cached_dbh_per_drh
       If set, the loaded drivers will be checked to ensure they don't have
       more than this number of cached connections. There is no default value.
       This limit is not enforced for every request.
   max_cached_sth_per_dbh
       If set, all the cached statement handles will be cleared once the
       number of cached statement handles rises above this limit. The default
       is 1000.
   forced_single_resultset
       If true, then only the first result set will be fetched and returned in
       the response.
   forced_response_attributes
       A reference to a data structure that can specify extra attributes to be
       returned in responses.
         forced_response_attributes => {
             DriverName => {
                 dbh => [ qw(dbh_attrib_name) ],
                 sth => [ qw(sth_attrib_name) ],
             },
         },
       This can be useful in cases where the driver has not implemented the
       private_attribute_info() method and DBI::Gofer::Execute's own fallback
       list of private attributes doesn't include the driver or attributes you
       need.
   track_recent
       If set, specifies the number of recent requests and responses that
       should be kept by the update_stats() method for diagnostics. See
       DBI::Gofer::Transport::mod_perl.
       Note that this setting can significantly increase memory use. Use with
       caution.
   forced_gofer_random
       Enable forced random failures and/or delays for testing. See
       "DBI_GOFER_RANDOM" below.
DRIVER-SPECIFIC ISSUES
       Gofer needs to know about any driver-private attributes that should
       have their values sent back to the client.
       If the driver doesn't support private_attribute_info() method, and very
       few do, then the module fallsback to using some hard-coded details, if
       available, for the driver being used. Currently hard-coded details are
       available for the mysql, Pg, Sybase, and SQLite drivers.
TESTING
       DBD::Gofer, DBD::Execute and related packages are well tested by
       executing the DBI test suite with DBI_AUTOPROXY configured to route all
       DBI calls via DBD::Gofer.
       Because Gofer includes timeout and 'retry on error' mechanisms there is
       a need for some way to trigger delays and/or errors. This can be done
       via the "forced_gofer_random" configuration item, or else the
       DBI_GOFER_RANDOM environment variable.
   DBI_GOFER_RANDOM
       The value of the "forced_gofer_random" configuration item (or else the
       DBI_GOFER_RANDOM environment variable) is treated as a series of tokens
       separated by commas.
       The tokens can be one of three types:
       fail=R%
           Set the current failure rate to R where R is a percentage.  The
           value R can be floating point, e.g., "fail=0.05%".  Negative values
           for R have special meaning, see below.
       err=N
           Sets the current failure err value to N (instead of the DBI's
           default 'standard err value' of 2000000000). This is useful when
           you want to simulate a specific error.
       delayN=R%
           Set the current random delay rate to R where R is a percentage, and
           set the current delay duration to N seconds. The values of R and N
           can be floating point, e.g., "delay0.5=0.2%".  Negative values for
           R have special meaning, see below.
           If R is an odd number (R % 2 == 1) then a message is logged via
           warn() which will be returned to, and echoed at, the client.
       methodname
           Applies the current fail, err, and delay values to the named
           method.  If neither a fail nor delay have been set yet then a
           warning is generated.
       For example:
         $executor = DBI::Gofer::Execute->new( {
           forced_gofer_random => "fail=0.01%,do,delay60=1%,execute",
         });
       will cause the do() method to fail for 0.01% of calls, and the
       execute() method to fail 0.01% of calls and be delayed by 60 seconds on
       1% of calls.
       If the percentage value ("R") is negative then instead of the failures
       being triggered randomly (via the rand() function) they are triggered
       via a sequence number. In other words ""fail=-20%"" will mean every
       fifth call will fail.  Each method has a distinct sequence number.
AUTHOR
       Tim Bunce, <http://www.tim.bunce.name>;
LICENCE AND COPYRIGHT
       Copyright (c) 2007, Tim Bunce, Ireland. All rights reserved.
       This module is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself. See perlartistic.

perl v5.16.3                      2013-04-04            DBI::Gofer::Execute(3)