Use client tools like `mc` to set and listen for event notifications using the [`event` sub-command](https://docs.min.io/docs/minio-client-complete-guide#events). MinIO SDK's [`BucketNotification` APIs](https://docs.min.io/docs/golang-client-api-reference#SetBucketNotification) can also be used. The notification message MinIO sends to publish an event is a JSON message with the following [structure](https://docs.aws.amazon.com/AmazonS3/latest/dev/notification-content-structure.html).
The AMQP configuration is located under the sub-system `notify_amqp` top-level key. Create a configuration key-value pair here for your AMQP instance. The key is a name for your AMQP endpoint, and the value is a collection of key-value parameters described in the table below.
MinIO supports persistent event store. The persistent store will backup events when the AMQP broker goes offline and replays it when the broker comes back online. The event store can be configured by setting the directory path in `queue_dir` field and the maximum limit of events in the queue_dir in `queue_limit` field. For eg, the `queue_dir` can be `/home/events` and `queue_limit` can be `1000`. By default, the `queue_limit` is set to 100000.
Use `mc admin config set` command to update the configuration for the deployment.Restart the MinIO server to put the changes into effect. The server will print a line like `SQS ARNs: arn:minio:sqs::1:amqp` at start-up if there were no errors.
An example configuration for RabbitMQ is shown below:
MinIO also sends with the notifications two headers: `minio-bucket` and `minio-event`. An exchange using the type "headers" can use this information to route the notifications to proper queues.
Note that, you can add as many AMQP server endpoint configurations as needed by providing an identifier (like "1" in the example above) for the AMQP instance and an object of per-server configuration parameters.
We will enable bucket event notification to trigger whenever a JPEG image is uploaded or deleted `images` bucket on `myminio` server. Here ARN value is `arn:minio:sqs::1:amqp`. To understand more about ARN please follow [AWS ARN](http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html) documentation.
The python program below waits on the queue exchange `bucketevents` and prints event notifications on the console. We use [Pika Python Client](https://www.rabbitmq.com/tutorials/tutorial-three-python.html) library to do this.
The MQTT configuration is located as `notify_mqtt` key. Create a configuration key-value pair here for your MQTT instance. The key is a name for your MQTT endpoint, and the value is a collection of key-value parameters described in the table below.
MinIO supports persistent event store. The persistent store will backup events when the MQTT broker goes offline and replays it when the broker comes back online. The event store can be configured by setting the directory path in `queue_dir` field and the maximum limit of events in the queue_dir in `queue_limit` field. For eg, the `queue_dir` can be `/home/events` and `queue_limit` can be `1000`. By default, the `queue_limit` is set to 100000.
Use `mc admin config set` command to update the configuration for the deployment. Restart the MinIO server to put the changes into effect. The server will print a line like `SQS ARNs: arn:minio:sqs::1:mqtt` at start-up if there were no errors.
MinIO supports any MQTT server that supports MQTT 3.1 or 3.1.1 and can connect to them over TCP, TLS, or a Websocket connection using `tcp://`, `tls://`, or `ws://` respectively as the scheme for the broker url. See the [Go Client](http://www.eclipse.org/paho/clients/golang/) documentation for more information.
Note that, you can add as many MQTT server endpoint configurations as needed by providing an identifier (like "1" in the example above) for the MQTT instance and an object of per-server configuration parameters.
We will enable bucket event notification to trigger whenever a JPEG image is uploaded or deleted `images` bucket on `myminio` server. Here ARN value is `arn:minio:sqs::1:mqtt`.
The python program below waits on mqtt topic `/minio` and prints event notifications on the console. We use [paho-mqtt](https://pypi.python.org/pypi/paho-mqtt/) library to do this.
When the _namespace_ format is used, MinIO synchronizes objects in the bucket with documents in the index. For each event in the MinIO, the server creates a document with the bucket and object name from the event as the document ID. Other details of the event are stored in the body of the document. Thus if an existing object is over-written in MinIO, the corresponding document in the Elasticsearch index is updated. If an object is deleted, the corresponding document is deleted from the index.
When the _access_ format is used, MinIO appends events as documents in an Elasticsearch index. For each event, a document with the event details, with the timestamp of document set to the event's timestamp is appended to an index. The ID of the documented is randomly generated by Elasticsearch. No documents are deleted or modified in this format.
MinIO requires a 5.x series version of Elasticsearch. This is the latest major release series. Elasticsearch provides version upgrade migration guidelines [here](https://www.elastic.co/guide/en/elasticsearch/reference/current/setup-upgrade.html).
The Elasticsearch configuration is located in the `notify_elasticsearch` key. Create a configuration key-value pair here for your Elasticsearch instance. The key is a name for your Elasticsearch endpoint, and the value is a collection of key-value parameters described in the table below.
notify_elasticsearch[:name] publish bucket notifications to Elasticsearch endpoints
ARGS:
url* (url) Elasticsearch server's address, with optional authentication info
index* (string) Elasticsearch index to store/update events, index is auto-created
format* (namespace*|access) 'namespace' reflects current bucket/object list and 'access' reflects a journal of object operations, defaults to 'namespace'
queue_dir (path) staging dir for undelivered messages e.g. '/home/events'
MINIO_NOTIFY_ELASTICSEARCH_URL* (url) Elasticsearch server's address, with optional authentication info
MINIO_NOTIFY_ELASTICSEARCH_INDEX* (string) Elasticsearch index to store/update events, index is auto-created
MINIO_NOTIFY_ELASTICSEARCH_FORMAT* (namespace*|access) 'namespace' reflects current bucket/object list and 'access' reflects a journal of object operations, defaults to 'namespace'
MINIO_NOTIFY_ELASTICSEARCH_QUEUE_DIR (path) staging dir for undelivered messages e.g. '/home/events'
MinIO supports persistent event store. The persistent store will backup events when the Elasticsearch broker goes offline and replays it when the broker comes back online. The event store can be configured by setting the directory path in `queue_dir` field and the maximum limit of events in the queue_dir in `queue_limit` field. For eg, the `queue_dir` can be `/home/events` and `queue_limit` can be `1000`. By default, the `queue_limit` is set to 100000.
If Elasticsearch has authentication enabled, the credentials can be supplied to MinIO via the `url` parameter formatted as `PROTO://USERNAME:PASSWORD@ELASTICSEARCH_HOST:PORT`.
Use `mc admin config set` command to update the configuration for the deployment. Restart the MinIO server to put the changes into effect. The server will print a line like `SQS ARNs: arn:minio:sqs::1:elasticsearch` at start-up if there were no errors.
Note that, you can add as many Elasticsearch server endpoint configurations as needed by providing an identifier (like "1" in the example above) for the Elasticsearch instance and an object of per-server configuration parameters.
We will now enable bucket event notifications on a bucket named `images`. Whenever a JPEG image is created/overwritten, a new document is added or an existing document is updated in the Elasticsearch index configured above. When an existing object is deleted, the corresponding document is deleted from the index. Thus, the rows in the Elasticsearch index, reflect the `.jpg` objects in the `images` bucket.
To configure this bucket notification, we need the ARN printed by MinIO in the previous step. Additional information about ARN is available [here](http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html).
With the `mc` tool, the configuration is very simple to add. Let us say that the MinIO server is aliased as `myminio` in our mc configuration. Execute the following:
This output shows that a document has been created for the event in Elasticsearch.
Here we see that the document ID is the bucket and object name. In case `access` format was used, the document ID would be automatically generated by Elasticsearch.
When the _namespace_ format is used, MinIO synchronizes objects in the bucket with entries in a hash. For each entry, the key is formatted as "bucketName/objectName" for an object that exists in the bucket, and the value is the JSON-encoded event data about the operation that created/replaced the object in MinIO. When objects are updated or deleted, the corresponding entry in the hash is also updated or deleted.
When the _access_ format is used, MinIO appends events to a list using [RPUSH](https://redis.io/commands/rpush). Each item in the list is a JSON encoded list with two items, where the first item is a timestamp string, and the second item is a JSON object containing event data about the operation that happened in the bucket. No entries appended to the list are updated or deleted by MinIO in this format.
The MinIO server configuration file is stored on the backend in json format.The Redis configuration is located in the `redis` key under the `notify` top-level key. Create a configuration key-value pair here for your Redis instance. The key is a name for your Redis endpoint, and the value is a collection of key-value parameters described in the table below.
notify_redis[:name] publish bucket notifications to Redis datastores
ARGS:
address* (address) Redis server's address. For example: `localhost:6379`
key* (string) Redis key to store/update events, key is auto-created
format* (namespace*|access) 'namespace' reflects current bucket/object list and 'access' reflects a journal of object operations, defaults to 'namespace'
password (string) Redis server password
queue_dir (path) staging dir for undelivered messages e.g. '/home/events'
MINIO_NOTIFY_REDIS_KEY* (string) Redis key to store/update events, key is auto-created
MINIO_NOTIFY_REDIS_FORMAT* (namespace*|access) 'namespace' reflects current bucket/object list and 'access' reflects a journal of object operations, defaults to 'namespace'
MINIO_NOTIFY_REDIS_PASSWORD (string) Redis server password
MINIO_NOTIFY_REDIS_QUEUE_DIR (path) staging dir for undelivered messages e.g. '/home/events'
MinIO supports persistent event store. The persistent store will backup events when the Redis broker goes offline and replays it when the broker comes back online. The event store can be configured by setting the directory path in `queue_dir` field and the maximum limit of events in the queue_dir in `queue_limit` field. For eg, the `queue_dir` can be `/home/events` and `queue_limit` can be `1000`. By default, the `queue_limit` is set to 100000.
Use `mc admin config set` command to update the configuration for the deployment.Restart the MinIO server to put the changes into effect. The server will print a line like `SQS ARNs: arn:minio:sqs::1:redis` at start-up if there were no errors.
Note that, you can add as many Redis server endpoint configurations as needed by providing an identifier (like "1" in the example above) for the Redis instance and an object of per-server configuration parameters.
We will now enable bucket event notifications on a bucket named `images`. Whenever a JPEG image is created/overwritten, a new key is added or an existing key is updated in the Redis hash configured above. When an existing object is deleted, the corresponding key is deleted from the Redis hash. Thus, the rows in the Redis hash, reflect the `.jpg` objects in the `images` bucket.
To configure this bucket notification, we need the ARN printed by MinIO in the previous step. Additional information about ARN is available [here](http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html).
With the `mc` tool, the configuration is very simple to add. Let us say that the MinIO server is aliased as `myminio` in our mc configuration. Execute the following:
Start the `redis-cli` Redis client program to inspect the contents in Redis. Run the `monitor` Redis command. This prints each operation performed on Redis as it occurs.
In case, `access` format was used, then `minio_events` would be a list, and the MinIO server would have performed an `RPUSH` to append to the list. A consumer of this list would ideally use `BLPOP` to remove list items from the left-end of the list.
MinIO supports persistent event store. The persistent store will backup events when the NATS broker goes offline and replays it when the broker comes back online. The event store can be configured by setting the directory path in `queue_dir` field and the maximum limit of events in the queue_dir in `queue_limit` field. For eg, the `queue_dir` can be `/home/events` and `queue_limit` can be `1000`. By default, the `queue_limit` is set to 100000.
Use `mc admin config set` command to update the configuration for the deployment.Restart MinIO server to reflect config changes. `bucketevents` is the subject used by NATS in this example.
MinIO server also supports [NATS Streaming mode](http://nats.io/documentation/streaming/nats-streaming-intro/) that offers additional functionality like `At-least-once-delivery`, and `Publisher rate limiting`. To configure MinIO server to send notifications to NATS Streaming server, update the MinIO server configuration file as follows:
Read more about sections `cluster_id`, `client_id` on [NATS documentation](https://github.com/nats-io/nats-streaming-server/blob/master/README.md). Section `maxPubAcksInflight` is explained [here](https://github.com/nats-io/stan.go#publisher-rate-limiting).
We will enable bucket event notification to trigger whenever a JPEG image is uploaded or deleted from `images` bucket on `myminio` server. Here ARN value is `arn:minio:sqs::1:nats`. To understand more about ARN please follow [AWS ARN](http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html) documentation.
2016/10/12 06:51:33 Received message '{"EventType":"s3:ObjectCreated:Put","Key":"images/myphoto.jpg","Records":[{"eventVersion":"2.0","eventSource":"aws:s3","awsRegion":"","eventTime":"2016-10-12T13:51:33Z","eventName":"s3:ObjectCreated:Put","userIdentity":{"principalId":"minio"},"requestParameters":{"sourceIPAddress":"[::1]:57106"},"responseElements":{},"s3":{"s3SchemaVersion":"1.0","configurationId":"Config","bucket":{"name":"images","ownerIdentity":{"principalId":"minio"},"arn":"arn:aws:s3:::images"},"object":{"key":"myphoto.jpg","size":56060,"eTag":"1d97bf45ecb37f7a7b699418070df08f","sequencer":"147CCD1AE054BFD0"}}}],"level":"info","msg":"","time":"2016-10-12T06:51:33-07:00"}
Received a message: {"EventType":"s3:ObjectCreated:Put","Key":"images/myphoto.jpg","Records":[{"eventVersion":"2.0","eventSource":"minio:s3","awsRegion":"","eventTime":"2017-07-07T18:46:37Z","eventName":"s3:ObjectCreated:Put","userIdentity":{"principalId":"minio"},"requestParameters":{"sourceIPAddress":"192.168.1.80:55328"},"responseElements":{"x-amz-request-id":"14CF20BD1EFD5B93","x-minio-origin-endpoint":"http://127.0.0.1:9000"},"s3":{"s3SchemaVersion":"1.0","configurationId":"Config","bucket":{"name":"images","ownerIdentity":{"principalId":"minio"},"arn":"arn:aws:s3:::images"},"object":{"key":"myphoto.jpg","size":248682,"eTag":"f1671feacb8bbf7b0397c6e9364e8c92","contentType":"image/jpeg","userDefined":{"content-type":"image/jpeg"},"versionId":"1","sequencer":"14CF20BD1EFD5B93"}},"source":{"host":"192.168.1.80","port":"55328","userAgent":"MinIO (linux; amd64) minio-go/2.0.4 mc/DEVELOPMENT.GOGET"}}],"level":"info","msg":"","time":"2017-07-07T11:46:37-07:00"}
Install [PostgreSQL](https://www.postgresql.org/) database server. For illustrative purposes, we have set the "postgres" user password as `password` and created a database called `minio_events` to store the events.
This notification target supports two formats: _namespace_ and _access_.
When the _namespace_ format is used, MinIO synchronizes objects in the bucket with rows in the table. It creates rows with two columns: key and value. The key is the bucket and object name of an object that exists in MinIO. The value is JSON encoded event data about the operation that created/replaced the object in MinIO. When objects are updated or deleted, the corresponding row from this table is updated or deleted respectively.
When the _access_ format is used, MinIO appends events to a table. It creates rows with two columns: event_time and event_data. The event_time is the time at which the event occurred in the MinIO server. The event_data is the JSON encoded event data about the operation on an object. No rows are deleted or modified in this format.
MinIO requires PostgreSQL version 9.5 or above. MinIO uses the [`INSERT ON CONFLICT`](https://www.postgresql.org/docs/9.5/static/sql-insert.html#SQL-ON-CONFLICT) (aka UPSERT) feature, introduced in version 9.5 and the [JSONB](https://www.postgresql.org/docs/9.4/static/datatype-json.html) data-type introduced in version 9.4.
The PostgreSQL configuration is located in the `notify_postgresql` key. Create a configuration key-value pair here for your PostgreSQL instance. The key is a name for your PostgreSQL endpoint, and the value is a collection of key-value parameters described in the table below.
connection_string* (string) Postgres server connection-string e.g. "host=localhost port=5432 dbname=minio_events user=postgres password=password sslmode=disable"
table* (string) DB table name to store/update events, table is auto-created
format* (namespace*|access) 'namespace' reflects current bucket/object list and 'access' reflects a journal of object operations, defaults to 'namespace'
queue_dir (path) staging dir for undelivered messages e.g. '/home/events'
queue_limit (number) maximum limit for undelivered messages, defaults to '100000'
max_open_connections (number) maximum number of open connections to the database, defaults to '2'
comment (sentence) optionally add a comment to this setting
MINIO_NOTIFY_POSTGRES_ENABLE* (on|off) enable notify_postgres target, default is 'off'
MINIO_NOTIFY_POSTGRES_CONNECTION_STRING* (string) Postgres server connection-string e.g. "host=localhost port=5432 dbname=minio_events user=postgres password=password sslmode=disable"
MINIO_NOTIFY_POSTGRES_TABLE* (string) DB table name to store/update events, table is auto-created
MINIO_NOTIFY_POSTGRES_FORMAT* (namespace*|access) 'namespace' reflects current bucket/object list and 'access' reflects a journal of object operations, defaults to 'namespace'
MINIO_NOTIFY_POSTGRES_QUEUE_DIR (path) staging dir for undelivered messages e.g. '/home/events'
MINIO_NOTIFY_POSTGRES_QUEUE_LIMIT (number) maximum limit for undelivered messages, defaults to '100000'
MINIO_NOTIFY_POSTGRES_COMMENT (sentence) optionally add a comment to this setting
MINIO_NOTIFY_POSTGRES_MAX_OPEN_CONNECTIONS (number) maximum number of open connections to the database, defaults to '2'
> NOTE: If the `max_open_connections` key or the environment variable `MINIO_NOTIFY_POSTGRES_MAX_OPEN_CONNECTIONS` is set to `0`, There will be no limit set on the number of
> open connections to the database. This setting is generally NOT recommended as the behavior may be inconsistent during recursive deletes in `namespace` format.
MinIO supports persistent event store. The persistent store will backup events when the PostgreSQL connection goes offline and replays it when the broker comes back online. The event store can be configured by setting the directory path in `queue_dir` field and the maximum limit of events in the queue_dir in `queue_limit` field. For eg, the `queue_dir` can be `/home/events` and `queue_limit` can be `1000`. By default, the `queue_limit` is set to 100000.
Use `mc admin config set` command to update the configuration for the deployment. Restart the MinIO server to put the changes into effect. The server will print a line like `SQS ARNs: arn:minio:sqs::1:postgresql` at start-up if there were no errors.
Note that, you can add as many PostgreSQL server endpoint configurations as needed by providing an identifier (like "1" in the example above) for the PostgreSQL instance and an object of per-server configuration parameters.
We will now enable bucket event notifications on a bucket named `images`. Whenever a JPEG image is created/overwritten, a new row is added or an existing row is updated in the PostgreSQL configured above. When an existing object is deleted, the corresponding row is deleted from the PostgreSQL table. Thus, the rows in the PostgreSQL table, reflect the `.jpg` objects in the `images` bucket.
To configure this bucket notification, we need the ARN printed by MinIO in the previous step. Additional information about ARN is available [here](http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html).
With the `mc` tool, the configuration is very simple to add. Let us say that the MinIO server is aliased as `myminio` in our mc configuration. Execute the following:
Install MySQL from [here](https://dev.mysql.com/downloads/mysql/). For illustrative purposes, we have set the root password as `password` and created a database called `miniodb` to store the events.
When the _namespace_ format is used, MinIO synchronizes objects in the bucket with rows in the table. It creates rows with two columns: key_name and value. The key_name is the bucket and object name of an object that exists in MinIO. The value is JSON encoded event data about the operation that created/replaced the object in MinIO. When objects are updated or deleted, the corresponding row from this table is updated or deleted respectively.
When the _access_ format is used, MinIO appends events to a table. It creates rows with two columns: event_time and event_data. The event_time is the time at which the event occurred in the MinIO server. The event_data is the JSON encoded event data about the operation on an object. No rows are deleted or modified in this format.
MinIO requires MySQL version 5.7.8 or above. MinIO uses the [JSON](https://dev.mysql.com/doc/refman/5.7/en/json.html) data-type introduced in version 5.7.8. We tested this setup on MySQL 5.7.17.
The MySQL configuration is located in the `notify_mysql` key. Create a configuration key-value pair here for your MySQL instance. The key is a name for your MySQL endpoint, and the value is a collection of key-value parameters described in the table below.
notify_mysql[:name] publish bucket notifications to MySQL databases. When multiple MySQL server endpoints are needed, a user specified "name" can be added for each configuration, (e.g."notify_mysql:myinstance").
dsn_string* (string) MySQL data-source-name connection string e.g. "<user>:<password>@tcp(<host>:<port>)/<database>"
table* (string) DB table name to store/update events, table is auto-created
format* (namespace*|access) 'namespace' reflects current bucket/object list and 'access' reflects a journal of object operations, defaults to 'namespace'
queue_dir (path) staging dir for undelivered messages e.g. '/home/events'
queue_limit (number) maximum limit for undelivered messages, defaults to '100000'
max_open_connections (number) maximum number of open connections to the database, defaults to '2'
comment (sentence) optionally add a comment to this setting
MINIO_NOTIFY_MYSQL_ENABLE* (on|off) enable notify_mysql target, default is 'off'
MINIO_NOTIFY_MYSQL_DSN_STRING* (string) MySQL data-source-name connection string e.g. "<user>:<password>@tcp(<host>:<port>)/<database>"
MINIO_NOTIFY_MYSQL_TABLE* (string) DB table name to store/update events, table is auto-created
MINIO_NOTIFY_MYSQL_FORMAT* (namespace*|access) 'namespace' reflects current bucket/object list and 'access' reflects a journal of object operations, defaults to 'namespace'
MINIO_NOTIFY_MYSQL_QUEUE_DIR (path) staging dir for undelivered messages e.g. '/home/events'
MINIO_NOTIFY_MYSQL_QUEUE_LIMIT (number) maximum limit for undelivered messages, defaults to '100000'
MINIO_NOTIFY_MYSQL_MAX_OPEN_CONNECTIONS (number) maximum number of open connections to the database, defaults to '2'
MINIO_NOTIFY_MYSQL_COMMENT (sentence) optionally add a comment to this setting
```
> NOTE: If the `max_open_connections` key or the environment variable `MINIO_NOTIFY_MYSQL_MAX_OPEN_CONNECTIONS` is set to `0`, There will be no limit set on the number of
> open connections to the database. This setting is generally NOT recommended as the behavior may be inconsistent during recursive deletes in `namespace` format.
MinIO supports persistent event store. The persistent store will backup events if MySQL connection goes offline and then replays the stored events when the broken connection comes back up. The event store can be configured by setting a directory path in `queue_dir` field, and the maximum number of events, which can be stored in a `queue_dir`, in `queue_limit` field. For example, `queue_dir` can be set to `/home/events` and `queue_limit` can be set to `1000`. By default, the `queue_limit` is set to `100000`.
Note that, you can add as many MySQL server endpoint configurations as needed by providing an identifier (like "myinstance" in the example above) for each MySQL instance desired.
Restart the MinIO server to put the changes into effect. The server will print a line like `SQS ARNs: arn:minio:sqs::myinstance:mysql` at start-up, if there are no errors.
We will now setup bucket notifications on a bucket named `images`. Whenever a JPEG image object is created/overwritten, a new row is added or an existing row is updated in the MySQL table configured above. When an existing object is deleted, the corresponding row is deleted from the MySQL table. Thus, the rows in the MySQL table, reflect the `.jpg` objects in the `images` bucket.
To configure this bucket notification, we need the ARN printed by MinIO in the previous step. Additional information about ARN is available [here](http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html).
With the `mc` tool, the configuration is very simple to add. Let us say that the MinIO server is aliased as `myminio` in our mc configuration. Execute the following:
MinIO requires Kafka version 0.10 or 0.9. Internally MinIO uses the [Shopify/sarama](https://github.com/Shopify/sarama/) library and so has the same version compatibility as provided by this library.
MinIO supports persistent event store. The persistent store will backup events when the kafka broker goes offline and replays it when the broker comes back online. The event store can be configured by setting the directory path in `queue_dir` field and the maximum limit of events in the queue_dir in `queue_limit` field. For eg, the `queue_dir` can be `/home/events` and `queue_limit` can be `1000`. By default, the `queue_limit` is set to 100000.
Use `mc admin config set` command to update the configuration for the deployment. Restart the MinIO server to put the changes into effect. The server will print a line like `SQS ARNs: arn:minio:sqs::1:kafka` at start-up if there were no errors.`bucketevents` is the topic used by kafka in this example.
We will enable bucket event notification to trigger whenever a JPEG image is uploaded or deleted from `images` bucket on `myminio` server. Here ARN value is `arn:minio:sqs::1:kafka`. To understand more about ARN please follow [AWS ARN](http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html) documentation.
MinIO supports persistent event store. The persistent store will backup events when the webhook goes offline and replays it when the broker comes back online. The event store can be configured by setting the directory path in `queue_dir` field and the maximum limit of events in the queue_dir in `queue_limit` field. For eg, the `queue_dir` can be `/home/events` and `queue_limit` can be `1000`. By default, the `queue_limit` is set to 100000.
Use `mc admin config set` command to update the configuration for the deployment. Here the endpoint is the server listening for webhook notifications. Save the settings and restart the MinIO server for changes to take effect. Note that the endpoint needs to be live and reachable when you restart your MinIO server.
We will enable bucket event notification to trigger whenever a JPEG image is uploaded to `images` bucket on `myminio` server. Here ARN value is `arn:minio:sqs::1:webhook`. To learn more about ARN please follow [AWS ARN](http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html) documentation.
We used [Thumbnailer](https://github.com/minio/thumbnailer) to listen for MinIO notifications when a new JPEG file is uploaded (HTTP PUT). Triggered by a notification, Thumbnailer uploads a thumbnail of new image to MinIO server. To start with, download and install Thumbnailer.
Thumbnailer starts running at `http://localhost:3000/`. Next, configure the MinIO server to send notifications to this URL (as mentioned in step 1) and use `mc` to set up bucket notifications (as mentioned in step 2). Then upload a JPEG image to MinIO server by
MinIO supports persistent event store. The persistent store will backup events when the NSQ broker goes offline and replays it when the broker comes back online. The event store can be configured by setting the directory path in `queue_dir` field and the maximum limit of events in the queue_dir in `queue_limit` field. For eg, the `queue_dir` can be `/home/events` and `queue_limit` can be `1000`. By default, the `queue_limit` is set to 100000.
Use `mc admin config set` command to update the configuration for the deployment. Restart the MinIO server to put the changes into effect. The server will print a line like `SQS ARNs: arn:minio:sqs::1:nsq` at start-up if there were no errors.
Note that, you can add as many NSQ daemon endpoint configurations as needed by providing an identifier (like "1" in the example above) for the NSQ instance and an object of per-server configuration parameters.
We will enable bucket event notification to trigger whenever a JPEG image is uploaded or deleted `images` bucket on `myminio` server. Here ARN value is `arn:minio:sqs::1:nsq`.
