Magento Infra

Database separation: Always use separate Redis databases:

• DB 0 → application cache
• DB 1 → full page cache
• DB 2 → sessions

Redis CLI Diagnostics

redis-cli -h redis -p 6379

# Key stats: hit rate, keyspace_hits, keyspace_misses — primary cache health indicator
redis-cli info stats | grep -E "keyspace_hits|keyspace_misses|instantaneous_ops"
# A healthy cache has keyspace_hits >> keyspace_misses (hit rate > 80%)

# Memory usage
redis-cli info memory

# Monitor live commands
redis-cli monitor

# List keys for this site (use your id_prefix)
redis-cli keys "site1_*" | head -20

# Count keys per database
redis-cli -n 0 dbsize   # app cache
redis-cli -n 1 dbsize   # FPC
redis-cli -n 2 dbsize   # sessions

# Flush specific database (cache only — not sessions)
redis-cli -n 0 flushdb
redis-cli -n 1 flushdb

# Check key TTL
redis-cli ttl "key_name"

# Flush everything (DANGER — clears sessions too)
redis-cli flushall

Memory Eviction Policies

Self-Hosted redis.conf

maxmemory 2gb
maxmemory-policy volatile-lru

# Persistence for sessions
save 900 1
save 300 10
appendonly yes
appendfsync everysec

tcp-keepalive 300

Cloud Redis (AWS ElastiCache / Azure Cache)

RabbitMQ

Purpose: Async operations, bulk processing, decoupled architecture.

env.php Configuration

'queue' => [
    'amqp' => [
        'host'        => 'rabbitmq',
        'port'        => '5672',
        'user'        => 'magento',
        'password'    => 'magento',
        'virtualhost' => '/',
        'ssl'         => false,
    ],
    'consumers_wait_for_messages' => 1
]

Queue Configuration Files

communication.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:Communication/etc/communication.xsd">
    <topic name="vendor.module.process"
           request="Vendor\Module\Api\Data\MessageInterface">
        <handler name="vendorModuleProcessor"
                 type="Vendor\Module\Model\Consumer"
                 method="process"/>
    </topic>
</config>

queue_topology.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework-message-queue:etc/topology.xsd">
    <exchange name="magento-topic-based-exchange" type="topic" connection="amqp">
        <binding id="vendorProcessBinding"
                 topic="vendor.module.process"
                 destinationType="queue"
                 destination="vendor.module.process.queue"/>
    </exchange>
</config>

queue_consumer.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework-message-queue:etc/consumer.xsd">
    <consumer name="vendor.module.process.consumer"
              queue="vendor.module.process.queue"
              handler="Vendor\Module\Model\Consumer::process"
              consumerInstance="Magento\Framework\MessageQueue\Consumer"
              connection="amqp"
              maxMessages="1000"/>
</config>

Consumer CLI Commands

# List all consumers
bin/magento queue:consumers:list

# Start a consumer
bin/magento queue:consumers:start vendor.module.process.consumer

# Start with message limit (recommended for cron-based consumers)
bin/magento queue:consumers:start vendor.module.process.consumer --max-messages=1000

# RabbitMQ management
rabbitmqctl list_queues name messages consumers
rabbitmqctl list_exchanges
rabbitmqctl list_bindings

env.php Cron-based Consumer Runner

'cron_consumers_runner' => [
    'cron_run'     => true,
    'max_messages' => 1000,
    'consumers'    => [
        'vendor.module.process.consumer'
    ]
]

Built-in Magento Consumers

OpenSearch / Elasticsearch

Purpose: Catalog search, layered navigation, search suggestions. Default: OpenSearch 2.x for Magento 2.4.6+

env.php Configuration

'system' => [
    'default' => [
        'catalog' => [
            'search' => [
                'engine'                          => 'opensearch',
                'opensearch_server_hostname'       => 'opensearch',
                'opensearch_server_port'           => '9200',
                'opensearch_index_prefix'          => 'magento2',
                'opensearch_enable_auth'           => '0',
                'opensearch_username'              => '',
                'opensearch_password'              => '',
                'opensearch_server_timeout'        => '15',
                'opensearch_minimum_should_match'  => '1'
            ]
        ]
    ]
]

CLI Configuration

# Set engine
bin/magento config:set catalog/search/engine opensearch
bin/magento config:set catalog/search/opensearch_server_hostname opensearch
bin/magento config:set catalog/search/opensearch_server_port 9200
bin/magento config:set catalog/search/opensearch_index_prefix magento2

# Reindex after config change
bin/magento indexer:reindex catalogsearch_fulltext
bin/magento cache:flush

Index Structure

magento2_product_1_v1           # Products for store view 1
magento2_product_2_v1           # Products for store view 2
magento2_category_1_v1          # Categories for store view 1
magento2_catalogsearch_fulltext_scope1_v1

OpenSearch REST API Diagnostics

# Cluster health
curl http://opensearch:9200/_cluster/health?pretty

# List all indices
curl http://opensearch:9200/_cat/indices?v

# Get index mapping
curl http://opensearch:9200/magento2_product_1_v1/_mapping?pretty

# Search products manually
curl -X GET http://opensearch:9200/magento2_product_1_v1/_search?pretty \
  -H 'Content-Type: application/json' \
  -d '{"query": {"match": {"name": "shirt"}}}'

# Index stats
curl http://opensearch:9200/magento2_product_1_v1/_stats?pretty

# Rebuild a corrupted or missing index — always go through the Magento indexer CLI
# NEVER delete OpenSearch indices directly via curl — Magento's metadata will be inconsistent
bin/magento indexer:reindex catalogsearch_fulltext
bin/magento cache:flush

opensearch.yml (Self-Hosted)

cluster.name: magento-cluster
node.name: node-1
network.host: 0.0.0.0
discovery.type: single-node

# Performance
indices.query.bool.max_clause_count: 10000
search.max_buckets: 100000
action.auto_create_index: true

# JVM heap: set to 50% of RAM, max 31GB in jvm.options
# -Xms4g -Xmx4g

Troubleshooting

Cloud OpenSearch (AWS OpenSearch Service)

MySQL / MariaDB Database Connections

Purpose: Separate read/write workloads to reduce lock contention on busy stores.

env.php — Multiple DB Connections

'db' => [
    'table_prefix' => '',
    'connection' => [
        // Primary connection — all reads/writes by default
        'default' => [
            'host'     => 'db',
            'dbname'   => 'magento',
            'username' => 'magento',
            'password' => 'magento',
            'active'   => '1',
        ],
        // Indexer connection — isolates indexing load from frontend reads
        'indexer' => [
            'host'     => 'db-replica',  // can be same host or a read replica
            'dbname'   => 'magento',
            'username' => 'magento',
            'password' => 'magento',
            'active'   => '1',
            'model'    => 'mysql4',
        ],
        // Checkout connection — isolates high-concurrency order writes
        'checkout' => [
            'host'     => 'db',
            'dbname'   => 'magento',
            'username' => 'magento',
            'password' => 'magento',
            'active'   => '1',
            'model'    => 'mysql4',
        ],
    ]
]

When to use each connection:

Key rule: The indexer connection is the highest-impact separation — indexing operations acquire table-level locks that block frontend reads on the same connection.

Instructions for LLM

• Redis: always use separate databases for cache (0), FPC (1), and sessions (2) — never share a database
• Redis: id_prefix must be unique per environment — prevents cache collisions between staging and production
• Redis: never flush DB 2 (sessions) in production — it logs out all customers
• RabbitMQ: consumers should be stopped before maintenance mode and restarted after
• RabbitMQ: always set maxMessages in production to prevent consumer memory leaks
• OpenSearch: the index prefix in env.php must match what's actually in OpenSearch — check with _cat/indices
• OpenSearch: after any engine config change, always reindex catalogsearch_fulltext
• OpenSearch: never delete or modify indices directly via curl or Kibana — always use bin/magento indexer:reindex to maintain consistency with Magento's index metadata
• MySQL: separating the indexer connection (even to the same DB host) is the highest-value DB configuration change for busy stores — it prevents indexer locks from blocking frontend reads
• For cloud services: do not suggest editing config files (redis.conf, opensearch.yml) — those are managed by the cloud provider