plucky (3) pmemlog_ctl_set.3.gz

NAME

       pmemlog_ctl_get()(DEPRECATED),  pmemlog_ctl_set()(DEPRECATED), pmemlog_ctl_exec()(DEPRECATED) - Query and
       modify libpmemlog internal behavior (DEPRECATED)

SYNOPSIS

              #include <libpmemlog.h>

              int pmemlog_ctl_get(PMEMlogpool *plp, const char *name, void *arg); (EXPERIMENTAL)
              int pmemlog_ctl_set(PMEMlogpool *plp, const char *name, void *arg); (EXPERIMENTAL)
              int pmemlog_ctl_exec(PMEMlogpool *plp, const char *name, void *arg); (EXPERIMENTAL)

DESCRIPTION

       The pmemlog_ctl_get(), pmemlog_ctl_set() and pmemlog_ctl_exec() functions provide a uniform interface for
       querying and modifying the internal behavior of libpmemlog(7) through the control (CTL) namespace.

       The  name  argument  specifies  an  entry point as defined in the CTL namespace specification.  The entry
       point description specifies whether the extra arg is required.  Those two parameters  together  create  a
       CTL  query.   The  functions  and  the entry points are thread-safe unless indicated otherwise below.  If
       there are special conditions for calling an entry point, they are explicitly stated in  its  description.
       The  functions  propagate  the  return value of the entry point.  If either name or arg is invalid, -1 is
       returned.

       If the provided ctl query is valid, the CTL functions will always return 0 on success and -1 on  failure,
       unless otherwise specified in the entry point description.

       See more in pmem_ctl(5) man page.

CTL NAMESPACE

       prefault.at_create | rw | global | int | int | - | boolean

       If  set,  every  page  of  the  pool will be touched and written to when the pool is created, in order to
       trigger  page  allocation  and  minimize  the  performance  impact  of  pagefaults.   Affects  only   the
       pmemlog_create() function.

       Always returns 0.

       prefault.at_open | rw | global | int | int | - | boolean

       If  set,  every  page  of  the  pool  will be touched and written to when the pool is opened, in order to
       trigger  page  allocation  and  minimize  the  performance  impact  of  pagefaults.   Affects  only   the
       pmemlog_open() function.

       Always returns 0.

       sds.at_create | rw | global | int | int | - | boolean

       If   set,   force-enables  or  force-disables  SDS  feature  during  pool  creation.   Affects  only  the
       pmemlog_create() function.  See pmempool_feature_query(3)  for  information  about  SDS  (SHUTDOWN_STATE)
       feature.

       Always returns 0.

       copy_on_write.at_open | rw | global | int | int | - | boolean

       If  set,  pool  is  mapped  in such a way that modifications don’t reach the underlying medium.  From the
       user’s perspective this means that when the pool is closed all changes are reverted.  This feature is not
       supported for pools located on Device DAX.

       Always returns 0.

CTL EXTERNAL CONFIGURATION

       In  addition  to  direct  function  call,  each  write  entry point can also be set using two alternative
       methods.

       The first method is to load a configuration directly from the PMEMLOG_CONF environment variable.

       The second method of loading an external  configuration  is  to  set  the  PMEMLOG_CONF_FILE  environment
       variable to point to a file that contains a sequence of ctl queries.

       See more in pmem_ctl(5) man page.

SEE ALSO

       libpmemlog(7), pmem_ctl(5) and <https://pmem.io>