Add data for WAL in pg_stat_io and backend statistics This commit adds WAL IO stats to both pg_stat_io view and per-backend IO statistics (pg_stat_get_backend_io()). This change is possible since f92c854cf406, as WAL IO is not counted in blocks in some code paths where its stats data is measured (like WAL read in xlogreader.c).
IOContext gains IOCONTEXT_INIT and IOObject IOOBJECT_WAL, with the following combinations allowed: - IOOBJECT_WAL/IOCONTEXT_NORMAL is used to track I/O operations done on already-created WAL segments. - IOOBJECT_WAL/IOCONTEXT_INIT is used for tracking I/O operations done when initializing WAL segments. The core changes are done in pg_stat_io.c, backend statistics inherit them. Backend statistics and pg_stat_io are now available for the WAL writer, the WAL receiver and the WAL summarizer processes. I/O timing data is controlled by the GUC track_io_timing, like the existing data of pg_stat_io for consistency. The timings related to IOOBJECT_WAL show up if the GUC is enabled (disabled by default). Bump pgstats file version, due to the additions in IOObject and IOContext, impacting the amount of data written for the fixed-numbered IO stats kind in the pgstats file. Author: Nazir Bilal Yavuz Reviewed-by: Bertrand Drouvot, Nitin Jadhav, Amit Kapila, Michael Paquier, Melanie Plageman, Bharath Rupireddy Discussion: https://postgr.es/m/CAN55FZ3AiQ+ZMxUuXnBpd0Rrh1YhwJ5FudkHg=ju0p+-w8t...@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/a051e71e28a12342a4fb39a3c149a197159f9c46 Modified Files -------------- doc/src/sgml/monitoring.sgml | 19 +++++-- src/backend/access/transam/xlog.c | 44 ++++++++++++---- src/backend/access/transam/xlogreader.c | 10 ++++ src/backend/access/transam/xlogrecovery.c | 12 +++++ src/backend/utils/activity/pgstat_backend.c | 6 +-- src/backend/utils/activity/pgstat_io.c | 79 +++++++++++++++++++++-------- src/include/pgstat.h | 6 ++- src/test/regress/expected/stats.out | 53 +++++++++++++++++++ src/test/regress/sql/stats.sql | 25 +++++++++ 9 files changed, 216 insertions(+), 38 deletions(-)
