- message queue system
- runs stand-alone (download) or embedded
- Amazon SQS-compatible interface
- fully asynchronous implementation, no blocking calls
Created and maintained by
ElasticMQ is a message queue system, offering an actor-based Scala and an SQS-compatible REST (query) interface.
ElasticMQ follows the semantics of SQS. Messages are received by polling the queue. When a message is received, it is blocked for a specified amount of time (the visibility timeout). If the message isn't deleted during that time, it will be again available for delivery. Moreover, queues and messages can be configured to always deliver messages with a delay.
The focus in SQS (and ElasticMQ) is to make sure that the messages are delivered. It may happen, however, that a message is delivered twice (if, for example, a client dies after receiving a message and processing it, but before deleting). That's why clients of ElasticMQ (and Amazon SQS) should be idempotent.
As ElasticMQ implements a subset of the SQS query (REST) interface, it is a great SQS alternative both for testing purposes (ElasticMQ is easily embeddable) and for creating systems which work both within and outside of the Amazon infrastructure.
The future will most probably bring even more exciting features :).
- Blog
- Forum (discussions, help): Google group.
You can download the stand-alone distribution here: https://s3/.../elasticmq-server-0.13.5.jar
Java 8 or above is required for running the server.
Simply run the jar and you should get a working server, which binds to localhost:9324:
java -jar elasticmq-server-0.13.5.jar
ElasticMQ uses Typesafe Config for configuration. To specify custom
configuration values, create a file (e.g. custom.conf), fill it in with the desired values, and pass it to the server:
java -Dconfig.file=custom.conf -jar elasticmq-server-0.13.5.jar
The config file may contain any configuration for Akka and ElasticMQ. Current ElasticMQ configuration values are:
include classpath("application.conf")
// What is the outside visible address of this ElasticMQ node
// Used to create the queue URL (may be different from bind address!)
node-address {
protocol = http
host = localhost
port = 9324
context-path = ""
}
rest-sqs {
enabled = true
bind-port = 9324
bind-hostname = "0.0.0.0"
// Possible values: relaxed, strict
sqs-limits = strict
}
// Should the node-address be generated from the bind port/hostname
// Set this to true e.g. when assigning port automatically by using port 0.
generate-node-address = false
queues {
// See next section
}
You can also provide an alternative Logback configuration file (the default is configured to log INFO logs and above to the console):
java -Dlogback.configurationFile=my_logback.xml -jar elasticmq-server-0.13.5.jar
Some of the responses include a queue URL. By default the urls will use http://localhost:9324 as the base URL.
To customize, you should properly set the protocol/host/port/context in the node-address setting (see above).
You can also set node-address.host to a special value, "*", which will cause any queue URLs created during a request
to use the path of the incoming request. This might be useful e.g. in containerized (Docker) deployments.
Note that changing the bind-port and bind-hostname settings does not affect the queue URLs in any way unless
generate-node-address is true. In that case, the bind host/port are used to create the node address. This is
useful when the port should be automatically assigned (use port 0 in such case, the selected port will be
visible in the logs).
Automatically creating queues on startup
Queues can be automatically created on startup by providing appropriate configuration:
The queues are specified in a custom configuration file. For example, create a custom.conf file with the following:
include classpath("application.conf")
queues {
queue1 {
defaultVisibilityTimeout = 10 seconds
delay = 5 seconds
receiveMessageWait = 0 seconds
deadLettersQueue {
name = "queue1-dead-letters"
maxReceiveCount = 3 // from 1 to 1000
}
}
queue1-dead-letters { }
}
All attributes are optional (except name and maxReceiveCount when a deadLettersQueue is defined).
val server = SQSRestServerBuilder.start()
// ... use ...
server.stopAndWait()
If you need to bind to a different host/port, there are configuration methods on the builder:
val server = SQSRestServerBuilder.withPort(9325).withInterface("localhost").start()
// ... use ...
server.stopAndWait()
You can also set a dynamic port with a port value of 0 or by using the method withDynamicPort. To retrieve the port (and other configuration) when using a dynamic port value you can access the server via waitUntilStarted for example:
val server = SQSRestServerBuilder.withDynamicPort().start()
server.waitUntilStarted().localAddress().getPort()
You can also provide a custom ActorSystem; for details see the javadocs.
Embedded ElasticMQ can be used from any JVM-based language (Java, Scala, etc.).
To use Amazon Java SDK as an interface to an ElasticMQ server you just need to change the endpoint:
client = new AmazonSQSClient(new BasicAWSCredentials("x", "x"))
client.setEndpoint("http://localhost:9324")
The endpoint value should be the same address as the NodeAddress provided as an argument to
SQSRestServerBuilder or in the configuration file.
The rest-sqs-testing-amazon-java-sdk module contains some more usage examples.
To use Amazon boto as an interface to an ElasticMQ server you set up the connection using:
region = boto.sqs.regioninfo.RegionInfo(name='elasticmq',
endpoint=sqs_endpoint)
conn = boto.connect_sqs(aws_access_key_id='x',
aws_secret_access_key='x',
is_secure=False,
port=sqs_port,
region=region)
where sqs_endpoint and sqs_port are the host and port.
The boto3 interface is different:
client = boto3.resource('sqs',
endpoint_url='http://localhost:9324',
region_name='elasticmq',
aws_secret_access_key='x',
aws_access_key_id='x',
use_ssl=False)
queue = client.get_queue_by_name(QueueName='queue1')
// Scala 2.12 and 2.11
val elasticmqSqs = "org.elasticmq" %% "elasticmq-rest-sqs" % "0.13.5"
// Scala 2.10
val elasticmqSqs = "org.elasticmq" %% "elasticmq-rest-sqs" % "0.7.1"
If you don't want the SQS interface, but just use the actors directly, you can add a dependency only to the core
module:
val elasticmqCore = "org.elasticmq" %% "elasticmq-core" % "0.13.5"
If you want to use a snapshot version, you will need to add the https://oss.sonatype.org/content/repositories/snapshots/ repository to your configuration.
Dependencies:
<dependency>
<groupId>org.elasticmq</groupId>
<artifactId>elasticmq-rest-sqs_2.11</artifactId>
<version>0.13.5</version>
</dependency>
If you want to use a snapshot version, you will need to add the https://oss.sonatype.org/content/repositories/snapshots/ repository to your configuration.
Until version 0.7.0, ElasticMQ included optional replication, journaling and an SQL message storage. These modules have been discontinued.
Stable: 0.13.5, 0.8.12
Development: 0.13.5-SNAPSHOT
ElasticMQ uses Slf4j for logging. By default no logger backend is included as a dependency, however Logback is recommended.
Tests done on a 2012 MBP, 2.6GHz, 16GB RAM, no replication. Throughput is in messages per second (messages are small).
Directly accessing the client:
Running test for [in-memory], iterations: 10, msgs in iteration: 100000, thread count: 1.
Overall in-memory throughput: 21326.054040
Running test for [in-memory], iterations: 10, msgs in iteration: 100000, thread count: 2.
Overall in-memory throughput: 26292.956117
Running test for [in-memory], iterations: 10, msgs in iteration: 100000, thread count: 10.
Overall in-memory throughput: 25591.155697
Through the SQS REST interface:
Running test for [rest-sqs + in-memory], iterations: 10, msgs in iteration: 1000, thread count: 20.
Overall rest-sqs + in-memory throughput: 2540.553587
Running test for [rest-sqs + in-memory], iterations: 10, msgs in iteration: 1000, thread count: 40.
Overall rest-sqs + in-memory throughput: 2600.002600
Note that both the client and the server were on the same machine.
Test class: org.elasticmq.performance.LocalPerformanceTest.
To build and run with debug (this will listen for a remote debugger on port 5005):
~/workspace/elasticmq $ sbt -jvm-debug 5005
> project elasticmq-server
> run
To build a jar-with-dependencies:
~/workspace/elasticmq $ sbt
> project elasticmq-server
> assembly
- Core: Scala and Akka.
- Rest server: Akka HTTP, a high-performance, asynchronous, REST/HTTP toolkit.
- Testing the SQS interface: Amazon Java SDK;
see the
rest-sqs-testing-amazon-java-sdkmodule for the testsuite.
- bug fixes
- fix akka dependencies
- properly returned only requrested attributes
- fix queue creation order in presence of DLQs
- update dependencies, akka & akka-http
- bug fix
- add dummy add permission endpoint
- add dead letter queue support (thx @mkorolyov)
- remove TODOs which caused problems with .NET client
- support for dynamic port allocation
- node address is generated from bind address if not specified
- bug fix
- updating dependencies, using Akka HTTP 10, builds for Scala 2.11 and 2.12
- fixing a bug with changing message visibility and long pooling
- updating Akka and other dependencies
- bug fix
- fixes handling of wait time seconds equal to 0 when receiving messages
- fixed bug to allow connecting using Perl client
- replace Spray with Akka
- increase message body size limits
- provide an option to create queues on startup
- add a special node-address setting:
*, which uses the incoming request url to create queue urls
- checking queue length if limits are strict
- downgrading typesafe-config to keep Java6 compatibility
- numeric attributes support (thx @sf-git)
- binary attributes support (thx @brainoutsource)
- dependency updates
- dependency updates, bug fixes
- adding support for the
QueueArnattribute
- supporting
PurgeQueueaction instead of a custom one
- custom action for clearing all messages from a queue
- bug fixes
- updating dependencies
- publishing to Maven Central
- increasing the bind timeout
- initial support for
String-valued message attributes (thx @hayesgm)
- fixing Node.JS compatibility
- fixing a bug when calculating queue attributes
- updating to Scala 2.11.1, Akka 2.3.3
- updating to Scala 2.11, Akka 2.3.2
- updating libraries to latest versions
- bug fixes
- reimplemented using Akka and Spray (actor-based, no blocking)
- long polling support
- bug fixes
- Scala 2.10 support
- Changing the way the stand-alone server is configured
- bug fixes
- properly handling SQS receipt handles - message can be deleted only when passing the most recent receipt handle
- using Sonatype's OSS repositories for releases
- library upgrades
- batch operations in SQS (send, receive, delete, change visibility)
- changed
SQSRestServerFactorytoSQSRestServerBuilder - "strict" and "relaxed" modes when creating an SQS server: the limits enforced by SQS are optionally checked, e.g. for batch operations (max 10 messages), maximum message size (64KB). Strict by default.
- stand-alone distribution (download)
- file log for message storage (journal)
- factoring out
storage-databasemodule, to decrease the dependencies of the core modules
- replication
- in-memory storage
- new native API
- bug fixes
- new SQS functions support
- testing with Amazon Java SDK
- bug fixes
- initial release
- DB storage
- SQS interface support