View Source Poolex (poolex v1.0.0)
Usage
In the most typical use of Poolex, you only need to start pool of workers as a child of your application.
children = [
{Poolex,
pool_id: :worker_pool,
worker_module: SomeWorker,
workers_count: 5}
]
Supervisor.start_link(children, strategy: :one_for_one)
Then you can execute any code on the workers with run/3
:
Poolex.run(:worker_pool, &(is_pid?(&1)), checkout_timeout: 1_000)
{:ok, true}
Fore more information see Getting Started
Summary
Types
Any valid GenServer's name. It may be an atom like :some_pool
or a tuple {:via, Registry, {MyApp.Registry, "pool"}
if you want to use Registry.
Option | Description | Example | Default value |
---|---|---|---|
pool_id | Identifier by which you will access the pool | :my_pool | option is required |
worker_module | Name of module that implements our worker | MyApp.Worker | option is required |
workers_count | How many workers should be running in the pool | 5 | option is required |
max_overflow | How many workers can be created over the limit | 2 | 0 |
worker_args | List of arguments passed to the start function | [:gg, "wp"] | [] |
worker_start_fun | Name of the function that starts the worker | :run | :start_link |
busy_workers_impl | Module that describes how to work with busy workers | SomeBusyWorkersImpl | Poolex.Workers.Impl.List |
idle_workers_impl | Module that describes how to work with idle workers | SomeIdleWorkersImpl | Poolex.Workers.Impl.List |
waiting_callers_impl | Module that describes how to work with callers queue | WaitingCallersImpl | Poolex.Callers.Impl.ErlangQueue |
pool_size_metrics | Whether to dispatch pool size metrics | true | false |
Option | Description | Example | Default value |
---|---|---|---|
checkout_timeout | How long we can wait for a worker on the call site | 60_000 | 5000 |
Process id of worker
.
Functions
Adds some idle workers to existing pool.
Returns a specification to start this module under a supervisor.
Returns detailed information about started pool.
Returns current state of started pool.
Removes some idle workers from existing pool. If the number of workers to remove is greater than the number of idle workers, all idle workers will be removed.
The main function for working with the pool.
Starts a Poolex process without links (outside of a supervision tree).
Starts a Poolex process linked to the current process.
Types
@type pool_id() :: GenServer.name()
Any valid GenServer's name. It may be an atom like :some_pool
or a tuple {:via, Registry, {MyApp.Registry, "pool"}
if you want to use Registry.
@type poolex_option() :: {:pool_id, pool_id()} | {:worker_module, module()} | {:workers_count, non_neg_integer()} | {:max_overflow, non_neg_integer()} | {:worker_args, [any()]} | {:worker_start_fun, atom()} | {:busy_workers_impl, module()} | {:idle_workers_impl, module()} | {:waiting_callers_impl, module()} | {:pool_size_metrics, boolean()}
Option | Description | Example | Default value |
---|---|---|---|
pool_id | Identifier by which you will access the pool | :my_pool | option is required |
worker_module | Name of module that implements our worker | MyApp.Worker | option is required |
workers_count | How many workers should be running in the pool | 5 | option is required |
max_overflow | How many workers can be created over the limit | 2 | 0 |
worker_args | List of arguments passed to the start function | [:gg, "wp"] | [] |
worker_start_fun | Name of the function that starts the worker | :run | :start_link |
busy_workers_impl | Module that describes how to work with busy workers | SomeBusyWorkersImpl | Poolex.Workers.Impl.List |
idle_workers_impl | Module that describes how to work with idle workers | SomeIdleWorkersImpl | Poolex.Workers.Impl.List |
waiting_callers_impl | Module that describes how to work with callers queue | WaitingCallersImpl | Poolex.Callers.Impl.ErlangQueue |
pool_size_metrics | Whether to dispatch pool size metrics | true | false |
@type run_option() :: {:checkout_timeout, timeout()}
Option | Description | Example | Default value |
---|---|---|---|
checkout_timeout | How long we can wait for a worker on the call site | 60_000 | 5000 |
@type worker() :: pid()
Process id of worker
.
Workers are processes launched in a pool.
Functions
@spec add_idle_workers!(pool_id(), pos_integer()) :: :ok | no_return()
Adds some idle workers to existing pool.
@spec child_spec([poolex_option()]) :: Supervisor.child_spec()
Returns a specification to start this module under a supervisor.
Options
Option | Description | Example | Default value |
---|---|---|---|
pool_id | Identifier by which you will access the pool | :my_pool | option is required |
worker_module | Name of module that implements our worker | MyApp.Worker | option is required |
workers_count | How many workers should be running in the pool | 5 | option is required |
max_overflow | How many workers can be created over the limit | 2 | 0 |
worker_args | List of arguments passed to the start function | [:gg, "wp"] | [] |
worker_start_fun | Name of the function that starts the worker | :run | :start_link |
busy_workers_impl | Module that describes how to work with busy workers | SomeBusyWorkersImpl | Poolex.Workers.Impl.List |
idle_workers_impl | Module that describes how to work with idle workers | SomeIdleWorkersImpl | Poolex.Workers.Impl.List |
waiting_callers_impl | Module that describes how to work with callers queue | WaitingCallersImpl | Poolex.Callers.Impl.ErlangQueue |
pool_size_metrics | Whether to dispatch pool size metrics | true | false |
Examples
children = [
Poolex.child_spec(pool_id: :worker_pool_1, worker_module: SomeWorker, workers_count: 5),
# or in another way
{Poolex, pool_id: :worker_pool_2, worker_module: SomeOtherWorker, workers_count: 5}
]
Supervisor.start_link(children, strategy: :one_for_one)
@spec get_debug_info(pool_id()) :: Poolex.Private.DebugInfo.t()
Returns detailed information about started pool.
Primarily needed to help with debugging. Avoid using this function in production.
Fields
* `busy_workers_count` - how many workers are busy right now.
* `busy_workers_pids` - list of busy workers.
* `idle_workers_count` - how many workers are ready to work.
* `idle_workers_pids` - list of idle workers.
* `max_overflow` - how many workers can be created over the limit.
* `overflow` - current count of workers launched over limit.
* `waiting_caller_pids` - list of callers processes.
* `worker_args` - what parameters are used to start the worker.
* `worker_module` - name of a module that describes a worker.
* `worker_start_fun` - what function is used to start the worker.
Examples
iex> Poolex.start(pool_id: :my_pool_3, worker_module: Agent, worker_args: [fn -> 0 end], workers_count: 5)
iex> debug_info = %Poolex.Private.DebugInfo{} = Poolex.get_debug_info(:my_pool_3)
iex> debug_info.busy_workers_count
0
iex> debug_info.idle_workers_count
5
@spec get_state(pool_id()) :: Poolex.Private.State.t()
Returns current state of started pool.
Primarily needed to help with debugging. Avoid using this function in production.
Examples
iex> Poolex.start(pool_id: :my_pool_2, worker_module: Agent, worker_args: [fn -> 0 end], workers_count: 5)
iex> state = %Poolex.Private.State{} = Poolex.get_state(:my_pool_2)
iex> state.worker_module
Agent
iex> is_pid(state.supervisor)
true
@spec remove_idle_workers!(pool_id(), pos_integer()) :: :ok | no_return()
Removes some idle workers from existing pool. If the number of workers to remove is greater than the number of idle workers, all idle workers will be removed.
@spec run(pool_id(), (worker :: pid() -> any()), [run_option()]) :: {:ok, any()} | {:error, :checkout_timeout}
The main function for working with the pool.
It takes a pool identifier, a function that takes a worker process id as an argument and returns any value.
When executed, an attempt is made to find a free worker with specified timeout (5 seconds by default).
You can set the timeout using the checkout_timeout
option.
Returns:
{:ok, result}
if the worker was found and the function was executed successfully.{:error, :checkout_timeout}
if no free worker was found before the timeout.
Examples
iex> Poolex.start_link(pool_id: :some_pool, worker_module: Agent, worker_args: [fn -> 5 end], workers_count: 1)
iex> Poolex.run(:some_pool, fn pid -> Agent.get(pid, &(&1)) end)
{:ok, 5}
@spec start([poolex_option()]) :: GenServer.on_start()
Starts a Poolex process without links (outside of a supervision tree).
See start_link/1 for more information.
Examples
iex> Poolex.start(pool_id: :my_pool, worker_module: Agent, worker_args: [fn -> 0 end], workers_count: 5)
iex> %Poolex.Private.State{worker_module: worker_module} = Poolex.get_state(:my_pool)
iex> worker_module
Agent
@spec start_link([poolex_option()]) :: GenServer.on_start()
Starts a Poolex process linked to the current process.
This is often used to start the Poolex as part of a supervision tree.
After the process is started, you can access it using the previously specified pool_id
.
Options
Option | Description | Example | Default value |
---|---|---|---|
pool_id | Identifier by which you will access the pool | :my_pool | option is required |
worker_module | Name of module that implements our worker | MyApp.Worker | option is required |
workers_count | How many workers should be running in the pool | 5 | option is required |
max_overflow | How many workers can be created over the limit | 2 | 0 |
worker_args | List of arguments passed to the start function | [:gg, "wp"] | [] |
worker_start_fun | Name of the function that starts the worker | :run | :start_link |
busy_workers_impl | Module that describes how to work with busy workers | SomeBusyWorkersImpl | Poolex.Workers.Impl.List |
idle_workers_impl | Module that describes how to work with idle workers | SomeIdleWorkersImpl | Poolex.Workers.Impl.List |
waiting_callers_impl | Module that describes how to work with callers queue | WaitingCallersImpl | Poolex.Callers.Impl.ErlangQueue |
pool_size_metrics | Whether to dispatch pool size metrics | true | false |
Examples
iex> Poolex.start_link(pool_id: :other_pool, worker_module: Agent, worker_args: [fn -> 0 end], workers_count: 5)
iex> %Poolex.Private.State{worker_module: worker_module} = Poolex.get_state(:other_pool)
iex> worker_module
Agent