1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
|
# frozen_string_literal: true
module Gitlab
module Database
module LoadBalancing
class SidekiqServerMiddleware
JobReplicaNotUpToDate = Class.new(::Gitlab::SidekiqMiddleware::RetryError)
MINIMUM_DELAY_INTERVAL_SECONDS = 0.8
def call(worker, job, _queue)
worker_class = worker.class
strategy = select_load_balancing_strategy(worker_class, job)
job['load_balancing_strategy'] = strategy.to_s
if use_primary?(strategy)
::Gitlab::Database::LoadBalancing::Session.current.use_primary!
elsif strategy == :retry
raise JobReplicaNotUpToDate, "Sidekiq job #{worker_class} JID-#{job['jid']} couldn't use the replica."\
" Replica was not up to date."
else
# this means we selected an up-to-date replica, but there is nothing to do in this case.
end
yield
ensure
clear
end
private
def clear
::Gitlab::Database::LoadBalancing.release_hosts
::Gitlab::Database::LoadBalancing::Session.clear_session
end
def use_primary?(strategy)
strategy.start_with?('primary')
end
def select_load_balancing_strategy(worker_class, job)
return :primary unless load_balancing_available?(worker_class)
wal_locations = get_wal_locations(job)
return :primary_no_wal if wal_locations.blank?
# Happy case: we can read from a replica.
return replica_strategy(worker_class, job) if databases_in_sync?(wal_locations)
sleep_if_needed(job)
if databases_in_sync?(wal_locations)
replica_strategy(worker_class, job)
elsif can_retry?(worker_class, job)
# Optimistic case: The worker allows retries and we have retries left.
:retry
else
# Sad case: we need to fall back to the primary.
:primary
end
end
def sleep_if_needed(job)
remaining_delay = MINIMUM_DELAY_INTERVAL_SECONDS - (Time.current.to_f - job['created_at'].to_f)
sleep remaining_delay if remaining_delay > 0 && remaining_delay < MINIMUM_DELAY_INTERVAL_SECONDS
end
def get_wal_locations(job)
job['dedup_wal_locations'] || job['wal_locations']
end
def load_balancing_available?(worker_class)
worker_class.include?(::ApplicationWorker) &&
worker_class.utilizes_load_balancing_capabilities? &&
worker_class.get_data_consistency_feature_flag_enabled?
end
def can_retry?(worker_class, job)
worker_class.get_data_consistency == :delayed && not_yet_retried?(job)
end
def replica_strategy(worker_class, job)
retried_before?(worker_class, job) ? :replica_retried : :replica
end
def retried_before?(worker_class, job)
worker_class.get_data_consistency == :delayed && !not_yet_retried?(job)
end
def not_yet_retried?(job)
# if `retry_count` is `nil` it indicates that this job was never retried
# the `0` indicates that this is a first retry
job['retry_count'].nil?
end
def databases_in_sync?(wal_locations)
locations = if Feature.enabled?(:indifferent_wal_location_keys)
wal_locations.with_indifferent_access
else
wal_locations
end
::Gitlab::Database::LoadBalancing.each_load_balancer.all? do |lb|
if (location = locations[lb.name])
lb.select_up_to_date_host(location)
else
# If there's no entry for a load balancer it means the Sidekiq
# job doesn't care for it. In this case we'll treat the load
# balancer as being in sync.
true
end
end
end
end
end
end
end
|
