From de3a2ea3b264a5625cda6d8968f75e9bfb4dbdcb Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Wed, 9 Oct 2024 08:07:48 +0900 Subject: [PATCH] Introduce two fields in EState to track parallel worker activity MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit These fields can be set by executor nodes to record how many parallel workers were planned to be launched and how many of them have been actually launched within the number initially planned. This data is able to give an approximation of the parallel worker draught a system is facing, making easier the tuning of related configuration parameters. These fields will be used by some follow-up patches to populate other parts of the system with their data. Author: Guillaume Lelarge, Benoit Lobréau Discussion: https://postgr.es/m/783bc7f7-659a-42fa-99dd-ee0565644e25@dalibo.com Discussion: https://postgr.es/m/CAECtzeWtTGOK0UgKXdDGpfTVSa5bd_VbUt6K6xn8P7X+_dZqKw@mail.gmail.com --- src/backend/executor/execUtils.c | 2 ++ src/backend/executor/nodeGather.c | 7 +++++++ src/backend/executor/nodeGatherMerge.c | 7 +++++++ src/include/nodes/execnodes.h | 5 +++++ 4 files changed, 21 insertions(+) diff --git a/src/backend/executor/execUtils.c b/src/backend/executor/execUtils.c index 5737f9f4ebd..6712302ec8c 100644 --- a/src/backend/executor/execUtils.c +++ b/src/backend/executor/execUtils.c @@ -158,6 +158,8 @@ CreateExecutorState(void) estate->es_sourceText = NULL; estate->es_use_parallel_mode = false; + estate->es_parallel_workers_to_launch = 0; + estate->es_parallel_workers_launched = 0; estate->es_jit_flags = 0; estate->es_jit = NULL; diff --git a/src/backend/executor/nodeGather.c b/src/backend/executor/nodeGather.c index 5d4ffe989cb..7f7edc7f9fc 100644 --- a/src/backend/executor/nodeGather.c +++ b/src/backend/executor/nodeGather.c @@ -182,6 +182,13 @@ ExecGather(PlanState *pstate) /* We save # workers launched for the benefit of EXPLAIN */ node->nworkers_launched = pcxt->nworkers_launched; + /* + * Count number of workers originally wanted and actually + * launched. + */ + estate->es_parallel_workers_to_launch += pcxt->nworkers_to_launch; + estate->es_parallel_workers_launched += pcxt->nworkers_launched; + /* Set up tuple queue readers to read the results. */ if (pcxt->nworkers_launched > 0) { diff --git a/src/backend/executor/nodeGatherMerge.c b/src/backend/executor/nodeGatherMerge.c index 45f6017c29e..bc99c0b4485 100644 --- a/src/backend/executor/nodeGatherMerge.c +++ b/src/backend/executor/nodeGatherMerge.c @@ -223,6 +223,13 @@ ExecGatherMerge(PlanState *pstate) /* We save # workers launched for the benefit of EXPLAIN */ node->nworkers_launched = pcxt->nworkers_launched; + /* + * Count number of workers originally wanted and actually + * launched. + */ + estate->es_parallel_workers_to_launch += pcxt->nworkers_to_launch; + estate->es_parallel_workers_launched += pcxt->nworkers_launched; + /* Set up tuple queue readers to read the results. */ if (pcxt->nworkers_launched > 0) { diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index aab59d681cf..e4698a28c4f 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -708,6 +708,11 @@ typedef struct EState bool es_use_parallel_mode; /* can we use parallel workers? */ + int es_parallel_workers_to_launch; /* number of workers to + * launch. */ + int es_parallel_workers_launched; /* number of workers actually + * launched. */ + /* The per-query shared memory area to use for parallel execution. */ struct dsa_area *es_query_dsa; -- 2.30.2