Class: Anomonitor::Collectors::SchemaDrift

Inherits:
Base
  • Object
show all
Defined in:
lib/anomonitor/collectors/schema_drift.rb

Overview

Detects schema drift across tenant schemas: missing/extra tables and missing/extra columns vs the majority baseline.

Requires Anomonitor.config.tenants to be set. PostgreSQL (information_schema.table_schema as tenant) is supported.

Instance Method Summary collapse

Instance Method Details

#collect ⇒ Object 



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# File 'lib/anomonitor/collectors/schema_drift.rb', line 14

def collect
  tenants = Tenancy.tenant_names
  if tenants.size < 2
    log_skip("need at least 2 tenants for schema drift (configure c.tenants)")
    return []
  end

  tables_by_tenant = load_tables(tenants)
  columns_by_tenant = load_columns(tenants)
  expected_tables = majority_keys(tables_by_tenant)
  expected_columns = majority_keys(columns_by_tenant)

  points = []
  tenants.each do |tenant|
    tenant_tables = tables_by_tenant[tenant] || Set.new
    tenant_columns = columns_by_tenant[tenant] || Set.new

    missing_tables = (expected_tables - tenant_tables).to_a.sort
    extra_tables = (tenant_tables - expected_tables).to_a.sort

    comparable_expected_cols = Set.new(
      expected_columns.select do |key|
        table = key.split(".", 2).first
        tenant_tables.include?(table)
      end
    )
    comparable_tenant_cols = Set.new(
      tenant_columns.select do |key|
        table = key.split(".", 2).first
        expected_tables.include?(table)
      end
    )
    missing_columns = (comparable_expected_cols - tenant_columns).to_a.sort
    extra_columns = (comparable_tenant_cols - expected_columns).to_a.sort

    points.concat(drift_points(tenant, "missing_tables", missing_tables))
    points.concat(drift_points(tenant, "extra_tables", extra_tables))
    points.concat(drift_points(tenant, "missing_columns", missing_columns))
    points.concat(drift_points(tenant, "extra_columns", extra_columns))
  end
  points
rescue StandardError => e
  Anomonitor.logger.warn("[Anomonitor] SchemaDrift collector error: #{e.message}")
  []
end