send_abort_for_kill

send_abort_for_kill — Send SIGABRT not SIGKILL to stuck child processes. Observed in PG16–19 Beta 3; its last measured boot default is off in PG19 Beta 3, with sighup context. This is a beta-snapshot fact and can change before PostgreSQL 19 GA.

Note

Fact — official short description: “Send SIGABRT not SIGKILL to stuck child processes.”

Identity

Type , Valuebool: Upstream pg_settings type
Context , Valuesighup: Takes effect after configuration reload
Unit , Value—: Raw unit
Range , Value—: Raw limits in the last observed version
Enum values , Value—: — for non-enum types
Category , ValueDeveloper Options: Upstream classification
Latest boot value , Valueoff: off

Lifecycle

Fact	Value
First observed	PG16
Present in	PG16–19 Beta 3
Removed in	No
Introduction commit	`51b5834cd53f` — Provide options for postmaster to kill child processes with SIGABRT.
Commit date	2022-11-21
Discussion	thread 1

Default history

Measured PG9.0–19 Beta 3 boot defaults
Versions	Raw `boot_val`	Unit	Human value
PG16–19 Beta 3	`off`	—	off

How it works

When a child does not exit after SIGQUIT, the postmaster normally escalates to SIGKILL after five seconds. send_abort_for_kill uses SIGABRT instead so the stuck child normally writes a core dump.

SIGABRT provides forensic state but can take time and disk space, potentially delaying crash recovery. It is not guaranteed to terminate as promptly as SIGKILL in every failure mode.

PostgreSQL does not clean generated cores. OS policy and monitoring must prevent repeated stuck processes from filling storage. Its SIGHUP context allows configuration reload without a server restart.

Tuning advice

Tip

Advice. These are workload-specific starting points and must be validated with measurements.

Workload	Guidance
OLTP	Do not tune production OLTP with send_abort_for_kill. Enable it only for a bounded reproduction with an owner, log/disk budget, rollback condition, and evidence-capture plan; restore the default immediately afterward.
OLAP	Long analytical runs can amplify send_abort_for_kill’s debug overhead and artifacts. Prefer standard EXPLAIN and statistics first, and isolate any developer experiment from normal users.
Small nodes	Keep send_abort_for_kill at its upstream default. A small host has less spare CPU, disk, connection, and log capacity for developer instrumentation.

Pigsty

Values use the fixed 8-vCPU, 32-GiB, 100-GiB SSD fixture and render the current Pigsty templates for PG19 Beta 3; this does not assert current Pigsty support for that historical or beta release.

Template	Effective value	Versus upstream boot	Source expression
OLTP	Unmodified	—	—
OLAP	Unmodified	—	—
CRIT	Unmodified	—	—
TINY	Unmodified	—	—

Caution

Advice — pending human review. Fact from the current Pigsty template projection: OLTP: PG16–19 Beta 3 unmodified; OLAP: PG16–19 Beta 3 unmodified; CRIT: PG16–19 Beta 3 unmodified; TINY: PG16–19 Beta 3 unmodified. No Pigsty-specific rationale is inferred from an absent override.

Common pitfalls

Leaving send_abort_for_kill enabled after the bounded diagnostic or recovery task.
Running the experiment on the only copy of production data.
Underestimating log, core-file, temporary-file, WAL, CPU, or connection-slot amplification.
Treating a server that merely starts or completes a query as proof that data and behavior are correct.

send_abort_for_crash · remove_temp_files_after_crash · log_error_verbosity · data_directory