check-dstate

Overview

Detects processes stuck in uninterruptible sleep (D-state) that exceed a specified age threshold. Identifies processes blocked on I/O operations or kernel calls that may indicate system issues.

D-state processes are typically waiting on disk I/O, network operations, or other kernel resources. Prolonged D-state indicates potential hardware or driver issues.

Dependencies

• strace: System call tracer for process inspection

Package Installation

# RHEL/CentOS
yum install procps-ng strace

# Ubuntu/Debian
apt-get install procps strace

Command-Line Options

Option	Type	Default	Description
--elapsed	Integer	300	Minimum process age (seconds) to trigger failure
--process-name	String	-	Filter by process name (regex supported); can specify multiple
--timeout	Integer	300	Command execution timeout in seconds
--sink	String	do_nothing	Telemetry sink destination
--sink-opts	Multiple	-	Sink-specific configuration
--verbose-out	Flag	False	Display detailed output
--log-level	Choice	INFO	DEBUG, INFO, WARNING, ERROR, CRITICAL
--log-folder	String	/var/log/fb-monitoring	Log directory
--heterogeneous-cluster-v1	Flag	False	Enable heterogeneous cluster support

Exit Conditions

Exit Code	Condition
OK (0)	Feature flag disabled (killswitch active)
OK (0)	No D-state processes exceed age threshold
WARN (1)	Exception during process check execution
CRITICAL (2)	One or more processes stuck in D-state

Usage Examples

Basic Check (Default 5 Minutes)

health_checks check-process check-dstate [CLUSTER] app

Custom Age Threshold (10 Minutes)

health_checks check-process check-dstate \
  --elapsed 600
  [CLUSTER] \
  app

Filter Specific Process

health_checks check-process check-dstate \
  --process-name "nfs.*" \
  --elapsed 180 \
  [CLUSTER] \
  app

Multiple Process Filters

health_checks check-process check-dstate \
  --process-name "nfs.*" \
  --process-name "mount.*" \
  --process-name "umount.*" \
  --elapsed 300 \
  [CLUSTER] \
  app

With Telemetry

health_checks check-process check-dstate \
  --sink otel \
  --sink-opts "log_resource_attributes={'attr_1': 'value1'}" \
  --verbose-out \
  [CLUSTER] \
  prolog

Debug Mode

health_checks -dstate \
  --log-level DEBUG \
  --verbose-out
  [CLUSTER] \
  app