From 676fbaf183639b37c382e784c89558a98ff7af9c Mon Sep 17 00:00:00 2001 From: benoit Date: Tue, 8 Oct 2024 12:39:41 +0200 Subject: [PATCH 1/5] Add a guc for parallel worker logging The new guc log_parallel_workers controls whether a log message is produced to display information on the number of workers spawned when a parallel query or utility is executed. The default value is `none` which disables logging. `all` displays information for all parallel queries, whereas `failures` displays information only when the number of workers launched is lower than the number of planned workers. This new parameter can help database administrators and developers diagnose performance issues related to parallelism and optimize the configuration of the system accordingly. --- doc/src/sgml/config.sgml | 18 ++++++++++++++++++ src/backend/utils/misc/guc_tables.c | 12 ++++++++++++ src/backend/utils/misc/postgresql.conf.sample | 1 + src/include/access/parallel.h | 15 +++++++++++++++ 4 files changed, 46 insertions(+) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 9707d5238d..5c04a27eb6 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -7696,6 +7696,24 @@ log_line_prefix = '%m [%p] %q%u@%d/%a ' + + log_parallel_workers (enum) + + log_parallel_workers configuration parameter + + + + + Controls whether a log message is produced to display information on the number of + workers spawned when a parallel query or utility is executed. The default value is + none which disables logging. all displays + information for all parallel queries, whereas failures displays + information only when the number of workers launched is lower than the number of + planned workers. + + + + log_parameter_max_length (integer) diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c index 686309db58..1f9e2b1a33 100644 --- a/src/backend/utils/misc/guc_tables.c +++ b/src/backend/utils/misc/guc_tables.c @@ -482,6 +482,7 @@ extern const struct config_enum_entry archive_mode_options[]; extern const struct config_enum_entry recovery_target_action_options[]; extern const struct config_enum_entry wal_sync_method_options[]; extern const struct config_enum_entry dynamic_shared_memory_options[]; +extern const struct config_enum_entry log_parallel_workers_options[]; /* * GUC option variables that are exported from this module @@ -526,6 +527,7 @@ int log_min_duration_statement = -1; int log_parameter_max_length = -1; int log_parameter_max_length_on_error = 0; int log_temp_files = -1; +int log_parallel_workers = LOG_PARALLEL_WORKERS_NONE; double log_statement_sample_rate = 1.0; double log_xact_sample_rate = 0; char *backtrace_functions; @@ -5196,6 +5198,16 @@ struct config_enum ConfigureNamesEnum[] = NULL, NULL, NULL }, + { + {"log_parallel_workers", PGC_SUSET, LOGGING_WHAT, + gettext_noop("Log information about parallel worker usage"), + NULL + }, + &log_parallel_workers, + LOG_PARALLEL_WORKERS_NONE, log_parallel_workers_options, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, NULL, NULL, NULL, NULL diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index 667e0dc40a..7cd9c0f3f8 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -619,6 +619,7 @@ #log_temp_files = -1 # log temporary files equal or larger # than the specified size in kilobytes; # -1 disables, 0 logs all temp files +#log_parallel_workers = none # none, all, failure #log_timezone = 'GMT' # - Process Title - diff --git a/src/include/access/parallel.h b/src/include/access/parallel.h index 69ffe5498f..ed33e545d7 100644 --- a/src/include/access/parallel.h +++ b/src/include/access/parallel.h @@ -19,6 +19,20 @@ #include "postmaster/bgworker.h" #include "storage/shm_mq.h" #include "storage/shm_toc.h" +#include "utils/guc.h" + +typedef enum log_parallel_workers_option_list { + LOG_PARALLEL_WORKERS_NONE=0, + LOG_PARALLEL_WORKERS_ALL, + LOG_PARALLEL_WORKERS_FAILURE, +} log_parallel_workers_option_list; + +static const struct config_enum_entry log_parallel_workers_options[] = { + {"none", LOG_PARALLEL_WORKERS_NONE, false}, + {"all", LOG_PARALLEL_WORKERS_ALL, false}, + {"failure", LOG_PARALLEL_WORKERS_FAILURE, false}, + {NULL, 0, false} +}; typedef void (*parallel_worker_main_type) (dsm_segment *seg, shm_toc *toc); @@ -56,6 +70,7 @@ typedef struct ParallelWorkerContext extern PGDLLIMPORT volatile sig_atomic_t ParallelMessagePending; extern PGDLLIMPORT int ParallelWorkerNumber; extern PGDLLIMPORT bool InitializingParallelWorker; +extern PGDLLEXPORT int log_parallel_workers; #define IsParallelWorker() (ParallelWorkerNumber >= 0) -- 2.46.2