components::ManagerControllerComponent Class Reference

#include <userver/components/manager_controller_component.hpp>

Detailed Description

Component that prepares the engine internals and starts all the other components.

Dynamic config

• USERVER_TASK_PROCESSOR_PROFILER_DEBUG
• USERVER_TASK_PROCESSOR_QOS

Static options:

Name	Description	Default value
coro_pool.initial_size	amount of coroutines to preallocate on startup	1000
coro_pool.max_size	max amount of coroutines to keep preallocated	4000
coro_pool.stack_size	size of a single coroutine	256 * 1024
event_thread_pool.threads	number of threads to process low level IO system calls (number of ev loops to start in libev)	2
event_thread_pool.thread_name	set OS thread name to this value	'event-worker'
components	dictionary of "component name": "options"	-
default_task_processor	name of the default task processor to use in components	-
task_processors.*NAME*.*OPTIONS*	dictionary of task processors to create and their options. See description below	-
mlock_debug_info	whether to mlock(2) process debug info to prevent major page faults on unwinding	true
disable_phdr_cache	whether to disable caching of phdr_info objects. Usable if rebuilding with cmake variable USERVER_DISABLE_PHDR_CACHE is off limits, and has the same effect	false
preheat_stacktrace_collector	whether to collect a dummy stacktrace at server start up (usable to avoid loading debug info at random point at runtime)	true

Static task_processor options:

Name	Description	Default value
guess-cpu-limit	guess optimal threads count	false
thread_name	set OS thread name to this value	Part of the task_processor name before the first '-' symbol with '-worker' appended; for example 'fs-worker' or 'main-worker'
worker_threads	threads count for the task processor	-
os-scheduling	OS scheduling mode for the task processor threads. 'idle' sets the lowest priority. 'low-priority' sets the priority below 'normal' but higher than 'idle'.	normal
spinning-iterations	tunes the number of spin-wait iterations in case of an empty task queue before threads go to sleep	1000
task-trace	optional dictionary of tracing options	empty (disabled)
task-trace.every	set N to trace each Nth task	1000
task-trace.max-context-switch-count	set upper limit of context switches to trace for a single task	1000
task-trace.logger	required name of logger to write traces to, should not be the 'default' logger	-

Tips and tricks on task-trace usage are described in Profiling context switches.

Static configuration example:

# yaml
components_manager:
  coro_pool:
    initial_size: 5000
    max_size: 50000
  default_task_processor: main-task-processor
  event_thread_pool:
    threads: 2
  task_processors:
    bg-task-processor:
      thread_name: bg-worker
      worker_threads: 2
      os-scheduling: idle
      task-trace:
        every: 1000
        max-context-switch-count: 1000
        logger: tracer
    fs-task-processor:
      thread_name: fs-worker
      worker_threads: 2
    main-task-processor:
      thread_name: main-worker
      worker_threads: 16
    monitor-task-processor:
      thread_name: monitor
      worker_threads: 2
  components:
    manager-controller:  # Nothing

Definition at line 66 of file manager_controller_component.hpp.

Inheritance diagram for components::ManagerControllerComponent:

Collaboration diagram for components::ManagerControllerComponent:

Public Member Functions
	ManagerControllerComponent (const components::ComponentConfig &config, const components::ComponentContext &context)

Static Public Attributes
static constexpr std::string_view	kName = "manager-controller"
	The default name of components::ManagerControllerComponent.

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The documentation for this class was generated from the following file:

• userver/components/manager_controller_component.hpp