exit_on_error (boolean)
#If on, any error will terminate the current session. By default, this is set to off, so that only FATAL errors will terminate the session.
restart_after_crash (boolean)
#When set to on, which is the default, Postgres Pro will automatically reinitialize after a backend crash. Leaving this value set to on is normally the best way to maximize the availability of the database. However, in some circumstances, such as when Postgres Pro is being invoked by clusterware, it may be useful to disable the restart so that the clusterware can gain control and take any actions it deems appropriate.
This parameter can only be set in the postgresql.conf
file or on the server command line.
data_sync_retry (boolean)
#When set to off, which is the default, Postgres Pro will raise a PANIC-level error on failure to flush modified data files to the file system. This causes the database server to crash. This parameter can only be set at server start.
On some operating systems, the status of data in the kernel's page cache is unknown after a write-back failure. In some cases it might have been entirely forgotten, making it unsafe to retry; the second attempt may be reported as successful, when in fact the data has been lost. In these circumstances, the only way to avoid data loss is to recover from the WAL after any failure is reported, preferably after investigating the root cause of the failure and replacing any faulty hardware.
If set to on, Postgres Pro will instead report an error but continue to run so that the data flushing operation can be retried in a later checkpoint. Only set it to on after investigating the operating system's treatment of buffered data in case of write-back failure.
recovery_init_sync_method (enum)
#
When set to fsync, which is the default,
Postgres Pro will recursively open and
synchronize all files in the data directory before crash recovery
begins. The search for files will follow symbolic links for the WAL
directory and each configured tablespace (but not any other symbolic
links). This is intended to make sure that all WAL and data files are
durably stored on disk before replaying changes. This applies whenever
starting a database cluster that did not shut down cleanly, including
copies created with pg_basebackup.
On Linux, syncfs may be used instead, to ask the
operating system to synchronize the file systems that contain the
data directory, the WAL files and each tablespace (but not any other
file systems that may be reachable through symbolic links). This may
be a lot faster than the fsync setting, because it
doesn't need to open each file one by one. On the other hand, it may
be slower if a file system is shared by other applications that
modify a lot of files, since those files will also be written to disk.
Furthermore, on versions of Linux before 5.8, I/O errors encountered
while writing data to disk may not be reported to
Postgres Pro, and relevant error messages may
appear only in kernel logs.
This parameter can only be set in the
postgresql.conf file or on the server command line.
crash_info (boolean)
#
When set to on, which is the default,
Postgres Pro will write diagnostic
information about a backend crash into a file.
This parameter can only be set at server start.
crash_info_dump (text)
#Specifies a comma-separated list of character strings that contain data sources to provide data for a crash dump. Possible values of the strings are as follows:
queries — query texts.
memory_context — Postgres Pro
memory context (see Section 48.3 for details).
system — information on the OS.
module — information on modules
loaded to the postgres process.
cpuinfo — information on the
processor: number of cores, instruction set, etc.
cpu_context:
Processor context registers.
General information on the error: signal number, signal code information, PID, PID of the parent process, user ID, etc.
virtual_memory — information on
virtual memory regions
instruction_pointer — bytes near RIP (the
return instruction pointer, which points to a memory address
indicating the progress of a program execution in memory).
stack — stack bytes. The stack is dumped
to an individual file in the directory where diagnostic information
about backend crashes is logged (PGDATA/crash_info.data extension.
The addresses of the upper and lower stack bounds are written to
the crash log file.
The default value is
system,module,queries,cpu_context,instruction_pointer.
This parameter can only be set at server start.
crash_info_location (string)
#
Specifies the directory where information
about a backend crash is to be stored. The value of
stderr sends information about the crash
to stderr. If this parameter is set to the
empty string '', which is the default,
the $PGDATA/crash_info directory is used.
If you wish to keep the files elsewhere, create the target directory
in advance and grant appropriate privileges.
This parameter can only be set at server start.
crash_info_timer (boolean)
#
Enables or disables dumping of long-running query state by timer, which
allows profiling such queries. The timer is launched by the interval
specified in crash_info_timer_interval and measures
query processing time. When query execution time exceeds the threshold
specified in crash_info_query_threshold, the query
state is dumped to disk. The default value is off.
For the timer to operate, crash_info_dump must be
set at least to queries.
This setting can be changed only by superusers using the
SET command in the current session or in the
configuration file globally.
This parameter can only be set at server start in the
postgresql.conf file. To re-read the parameter value,
restart the server or send the SIGHUP signal to
the main server process.
crash_info_timer_interval (integer)
#
Sets the time interval to launch the timer, in milliseconds. The default
value is 1000. This setting can be changed only by
superusers using the SET command in the current
session or in the configuration file globally.
This parameter can only be set at server start in the
postgresql.conf file. To re-read the parameter value,
restart the server or send the SIGHUP signal to
the main server process.
crash_info_query_threshold (integer)
#
Sets the threshold value for the query processing time, in milliseconds.
When reached, the query state is dumped to disk. The default value is
3000. This setting can be changed only by superusers
using the SET command in the current session or in the
configuration file globally.
This parameter can only be set at server start in the
postgresql.conf file. To re-read the parameter value,
restart the server or send the SIGHUP signal to
the main server process.