Migrate All Tenants Command

python manage.py migratealltenants

Overview

Runs database migrations for all tenants sequentially, ensuring every tenant's database/schema is up-to-date.

Purpose

Automates migration execution across the entire multi-tenant infrastructure: - Run migrations on all tenants in one command - Batch tenant updates - Ensure consistency across all tenants - Simplified deployment process

Usage

Basic Usage

python manage.py migratealltenants

Runs all pending migrations for every tenant in the system.

What Happens

Gets all Tenant objects from master database
For each tenant:
Retrieves tenant backend
Runs migrations for that tenant
Reports success or failure
Continues with next tenant
Summary of results

Output Example

$ python manage.py migratealltenants
Migrating tenant: acme
  users/0001_initial.py ... OK
  users/0002_alter_user_email.py ... OK
✓ Tenant 'acme' migrated successfully.

Migrating tenant: globex
  users/0001_initial.py ... OK
  users/0002_alter_user_email.py ... OK
  products/0001_initial.py ... OK
✓ Tenant 'globex' migrated successfully.

Migrating tenant: dev
  users/0001_initial.py ... OK
✓ Tenant 'dev' migrated successfully.

Migration Summary:
  ✓ acme - migrated successfully
  ✓ globex - migrated successfully
  ✓ dev - migrated successfully
  Total: 3 tenants migrated

Error Handling

Continues with next tenant if one fails:

Migrating tenant: acme
✓ Tenant 'acme' migrated successfully.

Migrating tenant: globex
✗ Migrations failed for tenant 'globex': Conflicting migrations
Continuing with next tenant...

Migrating tenant: dev
✓ Tenant 'dev' migrated successfully.

Migration Summary:
  ✓ acme - successful
  ✗ globex - FAILED
  ✓ dev - successful

Handle Failures

Tenants with failures should be handled separately:

# Identify failed tenant
# Fix migration conflict
# Re-run for specific tenant
python manage.py migratetenant --tenant-id=globex

Sequential Execution

Migrations run sequentially (one tenant at a time):

Start
  ↓
Migrate acme
  ↓
Migrate globex
  ↓
Migrate dev
  ↓
Complete

Benefits: - Lower resource usage - Predictable database locks - Easier debugging - Reduced connection pool pressure

Common Scenarios

Deploy New Feature

# Make migrations
python manage.py makemigrations

# Run migrations on all tenants
python manage.py migratealltenants

# Verify deployment
python manage.py showtenants

Regular Maintenance

# Scheduled cron job
0 2 * * * python manage.py migratealltenants >> /var/log/migrations.log 2>&1

Rolling Deployment

# Option 1: All at once
python manage.py migratealltenants

# Option 2: Staggered
for tenant_id in $(python manage.py showtenants --format=json | jq -r '.[].tenant_id'); do
    python manage.py migratetenant --tenant-id=$tenant_id
    sleep 60  # Wait between tenants
done

Database Isolation

Works correctly with different isolation strategies:

Database-per-Tenant:

acme_db
  django_migrations table
  user table
  product table

globex_db
  django_migrations table
  user table
  product table

$ migratealltenants
# Migrates each database separately
# Each tracks own migration history

Schema-per-Tenant:

shared_db
  public_acme schema
    django_migrations table
    user table
  public_globex schema
    django_migrations table
    user table

$ migratealltenants
# Migrates each schema separately
# Each schema tracks own migrations

Performance Considerations

Large Number of Tenants

For 100+ tenants, consider: - Run during maintenance window - Monitor disk space (each tenant needs space) - Monitor database connections - Use background job queue

Long-Running Migrations

For migrations taking hours: - Test on staging first - Plan maintenance window - Notify users of potential downtime - Monitor progress

Resource Usage

Each migration: - Uses database connection - May lock tables - May use memory - Sequential execution helps manage load

Monitoring

Check Status

python manage.py showtenants
# Lists all tenants and their status

View Migration History

# For specific tenant
python manage.py migratetenant --tenant-id=acme --plan

# All tenants
python manage.py showmigrations

Log Output

# Run with logging
python manage.py migratealltenants 2>&1 | tee migrations.log

# Check for errors
grep ERROR migrations.log

migratetenant - Migrate single tenant
showtenants - List all tenants
createtenant - Create new tenant
makemigrations - Create migration files
migrate - Django's standard migrate command