From 16a9da60cdf7b8eaf2f5fed82e4ab79cfdf33a6a Mon Sep 17 00:00:00 2001 From: Craig Ringer Date: Mon, 11 Jan 2021 10:33:10 +0800 Subject: [PATCH 4/4] SDT tracepoints for backend type and postmaster pid on startup For collecting stats on things like LWLock activity it's good to be able to identify a backend reliably, even without debuginfo available. --- src/backend/utils/init/miscinit.c | 5 +++++ src/backend/utils/misc/guc.c | 3 +++ src/backend/utils/misc/ps_status.c | 9 +++++++++ src/backend/utils/probes.d | 5 +++++ 4 files changed, 22 insertions(+) diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c index 8b73850d0d..01b5cccf85 100644 --- a/src/backend/utils/init/miscinit.c +++ b/src/backend/utils/init/miscinit.c @@ -233,6 +233,11 @@ GetBackendTypeDesc(BackendType backendType) { const char *backendDesc = "unknown process type"; + if (MyProcPid == PostmasterPid) + return "postmaster"; + else if (!IsUnderPostmaster) + return "standalone"; + switch (backendType) { case B_INVALID: diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index e337df42cb..b34cfcefdb 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -95,6 +95,7 @@ #include "utils/pg_lsn.h" #include "utils/plancache.h" #include "utils/portal.h" +#include "utils/probes.h" #include "utils/ps_status.h" #include "utils/rls.h" #include "utils/snapmgr.h" @@ -11834,6 +11835,8 @@ assign_application_name(const char *newval, void *extra) { /* Update the pg_stat_activity view */ pgstat_report_appname(newval); + + TRACE_POSTGRESQL_GUC_APPLICATION_NAME_ASSIGNED(newval); } static bool diff --git a/src/backend/utils/misc/ps_status.c b/src/backend/utils/misc/ps_status.c index 5819faaf2d..f6ea64a233 100644 --- a/src/backend/utils/misc/ps_status.c +++ b/src/backend/utils/misc/ps_status.c @@ -31,6 +31,7 @@ #include "pgstat.h" #include "utils/guc.h" #include "utils/ps_status.h" +#include "utils/probes.h" extern char **environ; bool update_process_title = true; @@ -265,6 +266,14 @@ init_ps_display(const char *fixed_part) if (!fixed_part) fixed_part = GetBackendTypeDesc(MyBackendType); + /* + * init_ps_display() is a useful time to report the backend type to + * tracing tools, since otherwise the probe would have to appear in + * many different main loops for different backend types. + */ + TRACE_POSTGRESQL_BACKEND_TYPE(MyBackendType, fixed_part); + TRACE_POSTGRESQL_POSTMASTER_PID(PostmasterPid); + #ifndef PS_USE_NONE /* no ps display for stand-alone backend */ if (!IsUnderPostmaster) diff --git a/src/backend/utils/probes.d b/src/backend/utils/probes.d index 608a89af91..0157c3432f 100644 --- a/src/backend/utils/probes.d +++ b/src/backend/utils/probes.d @@ -101,4 +101,9 @@ provider postgresql { probe wal__switch(); probe wal__buffer__write__dirty__start(); probe wal__buffer__write__dirty__done(); + + /* Useful probes for startup and process info, for when tracing a group of processes */ + probe backend__type(int backend_type, const char * backend_type_description); + probe postmaster__pid(int postmaster_pid); + probe guc__application__name__assigned(const char *newval); }; -- 2.29.2