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 re‐
       turned.

       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 trig‐
       ger 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 trig‐
       ger 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_cre‐
       ate() 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 meth‐
       ods.

       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  vari‐
       able 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>