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|
# frozen_string_literal: true
require 'spec_helper'
RSpec.describe Postgresql::ReplicationSlot do
describe '.in_use?' do
it 'returns true when replication slots are present' do
expect(described_class).to receive(:exists?).and_return(true)
expect(described_class.in_use?).to be_truthy
end
it 'returns false when replication slots are not present' do
expect(described_class.in_use?).to be_falsey
end
it 'returns false if the existence check is invalid' do
expect(described_class).to receive(:exists?).and_raise(ActiveRecord::StatementInvalid.new('PG::FeatureNotSupported'))
expect(described_class.in_use?).to be_falsey
end
end
describe '.lag_too_great?' do
before do
expect(described_class).to receive(:in_use?).and_return(true)
end
it 'does not raise an exception' do
expect { described_class.lag_too_great? }.not_to raise_error
end
it 'returns true when replication lag is too great' do
expect(described_class)
.to receive(:pluck)
.and_return([125.megabytes])
expect(described_class.lag_too_great?).to eq(true)
end
it 'returns false when more than one replicas is up to date enough' do
expect(described_class)
.to receive(:pluck)
.and_return([125.megabytes, 0.megabytes, 0.megabytes])
expect(described_class.lag_too_great?).to eq(false)
end
it 'returns false when replication lag is not too great' do
expect(described_class)
.to receive(:pluck)
.and_return([0.megabytes])
expect(described_class.lag_too_great?).to eq(false)
end
it 'returns false when there is a nil replication lag' do
expect(described_class)
.to receive(:pluck)
.and_return([0.megabytes, nil])
expect(described_class.lag_too_great?).to eq(false)
end
end
describe '#max_replication_slots' do
it 'returns the maximum number of replication slots' do
expect(described_class.max_replication_slots).to be >= 0
end
end
context 'with enough slots available' do
skip_examples = described_class.max_replication_slots <= described_class.count
before(:all) do
skip('max_replication_slots too small') if skip_examples
@current_slot_count = ApplicationRecord
.connection
.execute("SELECT COUNT(*) FROM pg_replication_slots;")
.first
.fetch('count')
.to_i
@current_unused_count = ApplicationRecord
.connection
.execute("SELECT COUNT(*) FROM pg_replication_slots WHERE active = 'f';")
.first
.fetch('count')
.to_i
ApplicationRecord
.connection
.execute("SELECT * FROM pg_create_physical_replication_slot('test_slot');")
end
after(:all) do
unless skip_examples
ApplicationRecord
.connection
.execute("SELECT pg_drop_replication_slot('test_slot');")
end
end
describe '#slots_count' do
it 'returns the number of replication slots' do
expect(described_class.count).to eq(@current_slot_count + 1)
end
end
describe '#unused_slots_count' do
it 'returns the number of unused replication slots' do
expect(described_class.unused_slots_count).to eq(@current_unused_count + 1)
end
end
describe '#max_retained_wal' do
it 'returns the retained WAL size' do
expect(described_class.max_retained_wal).not_to be_nil
end
end
describe '#slots_retained_bytes' do
it 'returns the number of retained bytes' do
slot = described_class.slots_retained_bytes.find {|x| x['slot_name'] == 'test_slot' }
expect(slot).not_to be_nil
expect(slot['retained_bytes']).to be_nil
end
end
end
end
|
