logstash/logstash-core/lib/logstash/pipeline.rb
Andrew Cholakian 86f776fafa Add more node stats + refactor stats internals
Add node stats mem endpoint

Fixes #5381
2016-06-15 14:34:14 -04:00

542 lines
17 KiB
Ruby

# encoding: utf-8
require "thread"
require "stud/interval"
require "concurrent"
require "logstash/namespace"
require "logstash/errors"
require "logstash/event"
require "logstash/config/file"
require "logstash/filters/base"
require "logstash/inputs/base"
require "logstash/outputs/base"
require "logstash/shutdown_watcher"
require "logstash/util/wrapped_synchronous_queue"
require "logstash/pipeline_reporter"
require "logstash/instrument/metric"
require "logstash/instrument/namespaced_metric"
require "logstash/instrument/null_metric"
require "logstash/instrument/collector"
require "logstash/output_delegator"
require "logstash/filter_delegator"
module LogStash; class Pipeline
attr_reader :inputs,
:filters,
:outputs,
:worker_threads,
:events_consumed,
:events_filtered,
:reporter,
:pipeline_id,
:logger,
:started_at,
:thread,
:config_str,
:settings,
:metric
MAX_INFLIGHT_WARN_THRESHOLD = 10_000
RELOAD_INCOMPATIBLE_PLUGINS = [
"LogStash::Inputs::Stdin"
]
def initialize(config_str, settings = LogStash::SETTINGS, namespaced_metric = nil)
@config_str = config_str
@logger = Cabin::Channel.get(LogStash)
@settings = settings
@pipeline_id = @settings.get_value("pipeline.id") || self.object_id
@reporter = LogStash::PipelineReporter.new(@logger, self)
@inputs = nil
@filters = nil
@outputs = nil
@worker_threads = []
# This needs to be configured before we evaluate the code to make
# sure the metric instance is correctly send to the plugins to make the namespace scoping work
@metric = namespaced_metric.nil? ? LogStash::Instrument::NullMetric.new : namespaced_metric
grammar = LogStashConfigParser.new
@config = grammar.parse(config_str)
if @config.nil?
raise LogStash::ConfigurationError, grammar.failure_reason
end
# This will compile the config to ruby and evaluate the resulting code.
# The code will initialize all the plugins and define the
# filter and output methods.
code = @config.compile
@code = code
# The config code is hard to represent as a log message...
# So just print it.
if @settings.get_value("config.debug") && logger.debug?
logger.debug("Compiled pipeline code", :code => code)
end
begin
eval(code)
rescue => e
raise
end
@input_queue = LogStash::Util::WrappedSynchronousQueue.new
@events_filtered = Concurrent::AtomicFixnum.new(0)
@events_consumed = Concurrent::AtomicFixnum.new(0)
# We generally only want one thread at a time able to access pop/take/poll operations
# from this queue. We also depend on this to be able to block consumers while we snapshot
# in-flight buffers
@input_queue_pop_mutex = Mutex.new
@input_threads = []
# @ready requires thread safety since it is typically polled from outside the pipeline thread
@ready = Concurrent::AtomicBoolean.new(false)
@running = Concurrent::AtomicBoolean.new(false)
@flushing = Concurrent::AtomicReference.new(false)
end # def initialize
def ready?
@ready.value
end
def safe_pipeline_worker_count
default = @settings.get_default("pipeline.workers")
pipeline_workers = @settings.get("pipeline.workers") #override from args "-w 8" or config
safe_filters, unsafe_filters = @filters.partition(&:threadsafe?)
plugins = unsafe_filters.collect { |f| f.config_name }
return pipeline_workers if unsafe_filters.empty?
if @settings.set?("pipeline.workers")
if pipeline_workers > 1
@logger.warn("Warning: Manual override - there are filters that might not work with multiple worker threads",
:worker_threads => pipeline_workers, :filters => plugins)
end
else
# user did not specify a worker thread count
# warn if the default is multiple
if default > 1
@logger.warn("Defaulting pipeline worker threads to 1 because there are some filters that might not work with multiple worker threads",
:count_was => default, :filters => plugins)
return 1 # can't allow the default value to propagate if there are unsafe filters
end
end
pipeline_workers
end
def filters?
return @filters.any?
end
def run
@started_at = Time.now
@thread = Thread.current
LogStash::Util.set_thread_name("[#{pipeline_id}]-pipeline-manager")
start_workers
@logger.log("Pipeline #{@pipeline_id} started")
# Block until all inputs have stopped
# Generally this happens if SIGINT is sent and `shutdown` is called from an external thread
transition_to_running
start_flusher # Launches a non-blocking thread for flush events
wait_inputs
transition_to_stopped
@logger.info("Input plugins stopped! Will shutdown filter/output workers.")
shutdown_flusher
shutdown_workers
@logger.log("Pipeline #{@pipeline_id} has been shutdown")
# exit code
return 0
end # def run
def transition_to_running
@running.make_true
end
def transition_to_stopped
@running.make_false
end
def running?
@running.true?
end
def stopped?
@running.false?
end
def start_workers
@inflight_batches = {}
@worker_threads.clear # In case we're restarting the pipeline
begin
start_inputs
@outputs.each {|o| o.register }
@filters.each {|f| f.register }
pipeline_workers = safe_pipeline_worker_count
batch_size = @settings.get("pipeline.batch.size")
batch_delay = @settings.get("pipeline.batch.delay")
max_inflight = batch_size * pipeline_workers
config_metric = metric.namespace([:stats, :pipelines, pipeline_id.to_s.to_sym, :config])
config_metric.gauge(:workers, pipeline_workers)
config_metric.gauge(:batch_size, batch_size)
config_metric.gauge(:batch_delay, batch_delay)
@logger.info("Starting pipeline",
"id" => self.pipeline_id,
"pipeline.workers" => pipeline_workers,
"pipeline.batch.size" => batch_size,
"pipeline.batch.delay" => batch_delay,
"pipeline.max_inflight" => max_inflight)
if max_inflight > MAX_INFLIGHT_WARN_THRESHOLD
@logger.warn "CAUTION: Recommended inflight events max exceeded! Logstash will run with up to #{max_inflight} events in memory in your current configuration. If your message sizes are large this may cause instability with the default heap size. Please consider setting a non-standard heap size, changing the batch size (currently #{batch_size}), or changing the number of pipeline workers (currently #{pipeline_workers})"
end
pipeline_workers.times do |t|
@worker_threads << Thread.new do
LogStash::Util.set_thread_name("[#{pipeline_id}]>worker#{t}")
worker_loop(batch_size, batch_delay)
end
end
ensure
# it is important to garantee @ready to be true after the startup sequence has been completed
# to potentially unblock the shutdown method which may be waiting on @ready to proceed
@ready.make_true
end
end
# Main body of what a worker thread does
# Repeatedly takes batches off the queue, filters, then outputs them
def worker_loop(batch_size, batch_delay)
running = true
namespace_events = metric.namespace([:stats, :events])
namespace_pipeline = metric.namespace([:stats, :pipelines, pipeline_id.to_s.to_sym, :events])
while running
# To understand the purpose behind this synchronize please read the body of take_batch
input_batch, signal = @input_queue_pop_mutex.synchronize { take_batch(batch_size, batch_delay) }
running = false if signal == LogStash::SHUTDOWN
@events_consumed.increment(input_batch.size)
namespace_events.increment(:in, input_batch.size)
namespace_pipeline.increment(:in, input_batch.size)
filtered_batch = filter_batch(input_batch)
if signal # Flush on SHUTDOWN or FLUSH
flush_options = (signal == LogStash::SHUTDOWN) ? {:final => true} : {}
flush_filters_to_batch(filtered_batch, flush_options)
end
@events_filtered.increment(filtered_batch.size)
namespace_events.increment(:filtered, filtered_batch.size)
namespace_pipeline.increment(:filtered, filtered_batch.size)
output_batch(filtered_batch)
namespace_events.increment(:out, filtered_batch.size)
namespace_pipeline.increment(:out, filtered_batch.size)
inflight_batches_synchronize { set_current_thread_inflight_batch(nil) }
end
end
def take_batch(batch_size, batch_delay)
batch = []
# Since this is externally synchronized in `worker_look` wec can guarantee that the visibility of an insight batch
# guaranteed to be a full batch not a partial batch
set_current_thread_inflight_batch(batch)
signal = false
batch_size.times do |t|
event = (t == 0) ? @input_queue.take : @input_queue.poll(batch_delay)
if event.nil?
next
elsif event == LogStash::SHUTDOWN || event == LogStash::FLUSH
# We MUST break here. If a batch consumes two SHUTDOWN events
# then another worker may have its SHUTDOWN 'stolen', thus blocking
# the pipeline. We should stop doing work after flush as well.
signal = event
break
else
batch << event
end
end
[batch, signal]
end
def filter_batch(batch)
batch.reduce([]) do |acc,e|
if e.is_a?(LogStash::Event)
filtered = filter_func(e)
filtered.each {|fe| acc << fe unless fe.cancelled?}
end
acc
end
rescue Exception => e
# Plugins authors should manage their own exceptions in the plugin code
# but if an exception is raised up to the worker thread they are considered
# fatal and logstash will not recover from this situation.
#
# Users need to check their configuration or see if there is a bug in the
# plugin.
@logger.error("Exception in pipelineworker, the pipeline stopped processing new events, please check your filter configuration and restart Logstash.",
"exception" => e, "backtrace" => e.backtrace)
raise
end
# Take an array of events and send them to the correct output
def output_batch(batch)
# Build a mapping of { output_plugin => [events...]}
outputs_events = batch.reduce(Hash.new { |h, k| h[k] = [] }) do |acc, event|
# We ask the AST to tell us which outputs to send each event to
# Then, we stick it in the correct bin
# output_func should never return anything other than an Array but we have lots of legacy specs
# that monkeypatch it and return nil. We can deprecate "|| []" after fixing these specs
outputs_for_event = output_func(event) || []
outputs_for_event.each { |output| acc[output] << event }
acc
end
# Now that we have our output to event mapping we can just invoke each output
# once with its list of events
outputs_events.each { |output, events| output.multi_receive(events) }
end
def set_current_thread_inflight_batch(batch)
@inflight_batches[Thread.current] = batch
end
def inflight_batches_synchronize
@input_queue_pop_mutex.synchronize do
yield(@inflight_batches)
end
end
def wait_inputs
@input_threads.each(&:join)
end
def start_inputs
moreinputs = []
@inputs.each do |input|
if input.threadable && input.threads > 1
(input.threads - 1).times do |i|
moreinputs << input.clone
end
end
end
@inputs += moreinputs
@inputs.each do |input|
input.register
start_input(input)
end
end
def start_input(plugin)
@input_threads << Thread.new { inputworker(plugin) }
end
def inputworker(plugin)
LogStash::Util::set_thread_name("[#{pipeline_id}]<#{plugin.class.config_name}")
begin
plugin.run(@input_queue)
rescue => e
if plugin.stop?
@logger.debug("Input plugin raised exception during shutdown, ignoring it.",
:plugin => plugin.class.config_name, :exception => e,
:backtrace => e.backtrace)
return
end
# otherwise, report error and restart
if @logger.debug?
@logger.error(I18n.t("logstash.pipeline.worker-error-debug",
:plugin => plugin.inspect, :error => e.to_s,
:exception => e.class,
:stacktrace => e.backtrace.join("\n")))
else
@logger.error(I18n.t("logstash.pipeline.worker-error",
:plugin => plugin.inspect, :error => e))
end
# Assuming the failure that caused this exception is transient,
# let's sleep for a bit and execute #run again
sleep(1)
retry
ensure
plugin.do_close
end
end # def inputworker
# initiate the pipeline shutdown sequence
# this method is intended to be called from outside the pipeline thread
# @param before_stop [Proc] code block called before performing stop operation on input plugins
def shutdown(&before_stop)
# shutdown can only start once the pipeline has completed its startup.
# avoid potential race conditoon between the startup sequence and this
# shutdown method which can be called from another thread at any time
sleep(0.1) while !ready?
# TODO: should we also check against calling shutdown multiple times concurently?
before_stop.call if block_given?
@logger.info "Closing inputs"
@inputs.each(&:do_stop)
@logger.info "Closed inputs"
end # def shutdown
# After `shutdown` is called from an external thread this is called from the main thread to
# tell the worker threads to stop and then block until they've fully stopped
# This also stops all filter and output plugins
def shutdown_workers
# Each worker thread will receive this exactly once!
@worker_threads.each do |t|
@logger.debug("Pushing shutdown", :thread => t.inspect)
@input_queue.push(LogStash::SHUTDOWN)
end
@worker_threads.each do |t|
@logger.debug("Shutdown waiting for worker thread #{t}")
t.join
end
@filters.each(&:do_close)
@outputs.each(&:do_close)
end
def plugin(plugin_type, name, *args)
args << {} if args.empty?
pipeline_scoped_metric = metric.namespace([:stats, :pipelines, pipeline_id.to_s.to_sym, :plugins])
klass = LogStash::Plugin.lookup(plugin_type, name)
if plugin_type == "output"
LogStash::OutputDelegator.new(@logger, klass, @settings.get("pipeline.output.workers"), pipeline_scoped_metric.namespace(:outputs), *args)
elsif plugin_type == "filter"
LogStash::FilterDelegator.new(@logger, klass, pipeline_scoped_metric.namespace(:filters), *args)
else
klass.new(*args)
end
end
# for backward compatibility in devutils for the rspec helpers, this method is not used
# in the pipeline anymore.
def filter(event, &block)
# filter_func returns all filtered events, including cancelled ones
filter_func(event).each { |e| block.call(e) }
end
# perform filters flush and yeild flushed event to the passed block
# @param options [Hash]
# @option options [Boolean] :final => true to signal a final shutdown flush
def flush_filters(options = {}, &block)
flushers = options[:final] ? @shutdown_flushers : @periodic_flushers
flushers.each do |flusher|
flusher.call(options, &block)
end
end
def start_flusher
# Invariant to help detect improper initialization
raise "Attempted to start flusher on a stopped pipeline!" if stopped?
@flusher_thread = Thread.new do
while Stud.stoppable_sleep(5, 0.1) { stopped? }
flush
break if stopped?
end
end
end
def shutdown_flusher
@flusher_thread.join
end
def flush
if @flushing.compare_and_set(false, true)
@logger.debug? && @logger.debug("Pushing flush onto pipeline")
@input_queue.push(LogStash::FLUSH)
end
end
# Calculate the uptime in milliseconds
#
# @return [Fixnum] Uptime in milliseconds, 0 if the pipeline is not started
def uptime
return 0 if started_at.nil?
((Time.now.to_f - started_at.to_f) * 1000.0).to_i
end
# perform filters flush into the output queue
# @param options [Hash]
# @option options [Boolean] :final => true to signal a final shutdown flush
def flush_filters_to_batch(batch, options = {})
flush_filters(options) do |event|
unless event.cancelled?
@logger.debug? and @logger.debug("Pushing flushed events", :event => event)
batch << event
end
end
@flushing.set(false)
end # flush_filters_to_output!
def plugin_threads_info
input_threads = @input_threads.select {|t| t.alive? }
worker_threads = @worker_threads.select {|t| t.alive? }
(input_threads + worker_threads).map {|t| LogStash::Util.thread_info(t) }
end
def stalling_threads_info
plugin_threads_info
.reject {|t| t["blocked_on"] } # known benign blocking statuses
.each {|t| t.delete("backtrace") }
.each {|t| t.delete("blocked_on") }
.each {|t| t.delete("status") }
end
def non_reloadable_plugins
(inputs + filters + outputs).select do |plugin|
RELOAD_INCOMPATIBLE_PLUGINS.include?(plugin.class.name)
end
end
# Sometimes we log stuff that will dump the pipeline which may contain
# sensitive information (like the raw syntax tree which can contain passwords)
# We want to hide most of what's in here
def inspect
{
:pipeline_id => @pipeline_id,
:settings => @settings.inspect,
:ready => @ready,
:running => @running,
:flushing => @flushing
}
end
end end