debian-mirror-gitlab/lib/gitlab/health_checks/fs_shards_check.rb
2017-09-10 17:25:29 +05:30

166 lines
6.2 KiB
Ruby

module Gitlab
module HealthChecks
class FsShardsCheck
extend BaseAbstractCheck
RANDOM_STRING = SecureRandom.hex(1000).freeze
COMMAND_TIMEOUT = '1'.freeze
TIMEOUT_EXECUTABLE = 'timeout'.freeze
class << self
def readiness
repository_storages.map do |storage_name|
begin
if !storage_circuitbreaker_test(storage_name)
HealthChecks::Result.new(false, 'circuitbreaker tripped', shard: storage_name)
elsif !storage_stat_test(storage_name)
HealthChecks::Result.new(false, 'cannot stat storage', shard: storage_name)
else
with_temp_file(storage_name) do |tmp_file_path|
if !storage_write_test(tmp_file_path)
HealthChecks::Result.new(false, 'cannot write to storage', shard: storage_name)
elsif !storage_read_test(tmp_file_path)
HealthChecks::Result.new(false, 'cannot read from storage', shard: storage_name)
else
HealthChecks::Result.new(true, nil, shard: storage_name)
end
end
end
rescue RuntimeError => ex
message = "unexpected error #{ex} when checking storage #{storage_name}"
Rails.logger.error(message)
HealthChecks::Result.new(false, message, shard: storage_name)
end
end
end
def metrics
repository_storages.flat_map do |storage_name|
[
storage_stat_metrics(storage_name),
storage_write_metrics(storage_name),
storage_read_metrics(storage_name),
storage_circuitbreaker_metrics(storage_name)
].flatten
end
end
private
def operation_metrics(ok_metric, latency_metric, **labels)
result, elapsed = yield
[
metric(latency_metric, elapsed, **labels),
metric(ok_metric, result ? 1 : 0, **labels)
]
rescue RuntimeError => ex
Rails.logger.error("unexpected error #{ex} when checking #{ok_metric}")
[metric(ok_metric, 0, **labels)]
end
def repository_storages
@repository_storage ||= Gitlab::CurrentSettings.current_application_settings.repository_storages
end
def storages_paths
@storage_paths ||= Gitlab.config.repositories.storages
end
def exec_with_timeout(cmd_args, *args, &block)
Gitlab::Popen.popen([TIMEOUT_EXECUTABLE, COMMAND_TIMEOUT].concat(cmd_args), *args, &block)
end
def with_temp_file(storage_name)
temp_file_path = Dir::Tmpname.create(%w(fs_shards_check +deleted), storage_path(storage_name)) { |path| path }
yield temp_file_path
ensure
delete_test_file(temp_file_path)
end
def storage_path(storage_name)
storages_paths&.dig(storage_name, 'path')
end
# All below test methods use shell commands to perform actions on storage volumes.
# In case a storage volume have connectivity problems causing pure Ruby IO operation to wait indefinitely,
# we can rely on shell commands to be terminated once `timeout` kills them.
#
# However we also fallback to pure Ruby file operations in case a specific shell command is missing
# so we are still able to perform healthchecks and gather metrics from such system.
def delete_test_file(tmp_path)
_, status = exec_with_timeout(%W{ rm -f #{tmp_path} })
status.zero?
rescue Errno::ENOENT
File.delete(tmp_path) rescue Errno::ENOENT
end
def storage_stat_test(storage_name)
stat_path = File.join(storage_path(storage_name), '.')
begin
_, status = exec_with_timeout(%W{ stat #{stat_path} })
status.zero?
rescue Errno::ENOENT
File.exist?(stat_path) && File::Stat.new(stat_path).readable?
end
end
def storage_write_test(tmp_path)
_, status = exec_with_timeout(%W{ tee #{tmp_path} }) do |stdin|
stdin.write(RANDOM_STRING)
end
status.zero?
rescue Errno::ENOENT
written_bytes = File.write(tmp_path, RANDOM_STRING) rescue Errno::ENOENT
written_bytes == RANDOM_STRING.length
end
def storage_read_test(tmp_path)
_, status = exec_with_timeout(%W{ diff #{tmp_path} - }) do |stdin|
stdin.write(RANDOM_STRING)
end
status.zero?
rescue Errno::ENOENT
file_contents = File.read(tmp_path) rescue Errno::ENOENT
file_contents == RANDOM_STRING
end
def storage_circuitbreaker_test(storage_name)
Gitlab::Git::Storage::CircuitBreaker.new(storage_name).perform { "OK" }
rescue Gitlab::Git::Storage::Inaccessible
nil
end
def storage_stat_metrics(storage_name)
operation_metrics(:filesystem_accessible, :filesystem_access_latency_seconds, shard: storage_name) do
with_timing { storage_stat_test(storage_name) }
end
end
def storage_write_metrics(storage_name)
operation_metrics(:filesystem_writable, :filesystem_write_latency_seconds, shard: storage_name) do
with_temp_file(storage_name) do |tmp_file_path|
with_timing { storage_write_test(tmp_file_path) }
end
end
end
def storage_read_metrics(storage_name)
operation_metrics(:filesystem_readable, :filesystem_read_latency_seconds, shard: storage_name) do
with_temp_file(storage_name) do |tmp_file_path|
storage_write_test(tmp_file_path) # writes data used by read test
with_timing { storage_read_test(tmp_file_path) }
end
end
end
def storage_circuitbreaker_metrics(storage_name)
operation_metrics(:filesystem_circuitbreaker,
:filesystem_circuitbreaker_latency_seconds,
shard: storage_name) do
with_timing { storage_circuitbreaker_test(storage_name) }
end
end
end
end
end
end