18.14. Error Handling
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 whenPostgres 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.conffile 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.
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 (seeSection 45.3 for details).system— information on the OS.module— information on modules loaded to thepostgresprocess.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 regionsinstruction_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.dataextension. 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
stderrsends information about the crash tostderr. If this parameter is set to the empty string'', which is the default, the$PGDATA/crash_infodirectory 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 incrash_info_timer_interval and measures query processing time. When query execution time exceeds the threshold specified incrash_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 toqueries. This setting can be changed only by superusers using theSETcommand in the current session or in the configuration file globally.This parameter can only be set at server start in the
postgresql.conffile. To re-read the parameter value, restart the server or send theSIGHUP 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 theSETcommand in the current session or in the configuration file globally.This parameter can only be set at server start in the
postgresql.conffile. To re-read the parameter value, restart the server or send theSIGHUP 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 theSETcommand in the current session or in the configuration file globally.This parameter can only be set at server start in the
postgresql.conffile. To re-read the parameter value, restart the server or send theSIGHUP signal to the main server process.