Redis Simple Message Queue
A lightweight message queue for Node.js that requires no dedicated queue server. Just a Redis server.
tl;dr: If you run a Redis server and currently use Amazon SQS or a similar message queue you might as well use this fast little replacement. Using a shared Redis server multiple Node.js processes can send / receive messages.
Features
- Lightweight: Just Redis and ~500 lines of javascript.
- Speed: Send and receive 1000+ messages per second on an average machine. It's just Redis.
- Guaranteed delivery of a message to exactly one recipient within a messages visibility timeout.
- Received messages that are not deleted will reappear after the visibility timeout.
- Test coverage
- A message is deleted by the message id. The message id is returned by the
sendMessage
and receiveMessage
method. - Messages stay in the queue unless deleted.
- Optional RESTful interface via rest-rsmq
- Typescript Typings ❤️
Note: RSMQ uses the Redis EVAL command (LUA scripts) so the minimum Redis version is 2.6+.
Usage
- After creating a queue you can send messages to that queue.
- The messages will be handled in a FIFO (first in first out) manner unless specified with a delay.
- Every message has a unique
id
that you can use to delete the message. - The
sendMessage
method will return the id
for a sent message. - The
receiveMessage
method will return an id
along with the message and some stats. - Should you not delete the message it will be eligible to be received again after the visibility timeout is reached.
- Please have a look at the
createQueue
and receiveMessage
methods described below for optional parameters like visibility timeout and delay.
Installation
npm install rsmq
Modules for RSMQ
To keep the core of RSMQ small additional functionality is available as modules:
RSMQ in other languages
The simplicity of RSMQ is useful in other languages. Here is a list of implementations in other languages:
- Java RSMQ for Java. See #48
- PHP RSMQ for PHP (work in progress)
Note: Should you plan to port RSQM to another language please make sure to have tests to insure compatibility with all RSMQ clients. And of course: let me know so i can mention your port here.
Example
Initialize
RedisSMQ = require("rsmq");
rsmq = new RedisSMQ( {host: "127.0.0.1", port: 6379, ns: "rsmq"} );
Parameters for RedisSMQ via an options object:
host
(String): optional (Default: "127.0.0.1") The Redis serverport
(Number): optional (Default: 6379) The Redis portoptions
(Object): optional (Default: {}) The Redis options object.client
(RedisClient): optional A existing redis client instance. host
and server
will be ignored.ns
(String): optional (Default: "rsmq") The namespace prefix used for all keys created by RSMQrealtime
(Boolean): optional (Default: false) Enable realtime PUBLISH of new messages (see the Realtime section)
Create a queue
Please look at the Methods section for optional parameters when creating a queue.
rsmq.createQueue({qname:"myqueue"}, function (err, resp) {
if (resp===1) {
console.log("queue created")
}
});
Send a message
rsmq.sendMessage({qname:"myqueue", message:"Hello World"}, function (err, resp) {
if (resp) {
console.log("Message sent. ID:", resp);
}
});
Receive a message
rsmq.receiveMessage({qname:"myqueue"}, function (err, resp) {
if (resp.id) {
console.log("Message received.", resp)
}
else {
console.log("No messages for me...")
}
});
Delete a message
rsmq.deleteMessage({qname:"myqueue", id:"dhoiwpiirm15ce77305a5c3a3b0f230c6e20f09b55"}, function (err, resp) {
if (resp===1) {
console.log("Message deleted.")
}
else {
console.log("Message not found.")
}
});
List queues
rsmq.listQueues( function (err, queues) {
if( err ){
console.error( err )
return
}
console.log("Active queues: " + queues.join( "," ) )
});
Methods
changeMessageVisibility
Change the visibility timer of a single message.
The time when the message will be visible again is calculated from the current time (now) + vt
.
Parameters:
qname
(String): The Queue name.id
(String): The message id.vt
(Number): The length of time, in seconds, that this message will not be visible. Allowed values: 0-9999999 (around 115 days)
Returns:
1
if successful, 0
if the message was not found.
createQueue
Create a new queue.
Parameters:
qname
(String): The Queue name. Maximum 160 characters; alphanumeric characters, hyphens (-), and underscores (_) are allowed.vt
(Number): optional (Default: 30) The length of time, in seconds, that a message received from a queue will be invisible to other receiving components when they ask to receive messages. Allowed values: 0-9999999 (around 115 days)delay
(Number): optional (Default: 0) The time in seconds that the delivery of all new messages in the queue will be delayed. Allowed values: 0-9999999 (around 115 days)maxsize
(Number): optional (Default: 65536) The maximum message size in bytes. Allowed values: 1024-65536 and -1 (for unlimited size)
Returns:
deleteMessage
Parameters:
qname
(String): The Queue name.id
(String): message id to delete.
Returns:
1
if successful, 0
if the message was not found.
deleteQueue
Deletes a queue and all messages.
Parameters:
qname
(String): The Queue name.
Returns:
getQueueAttributes
Get queue attributes, counter and stats
Parameters:
qname
(String): The Queue name.
Returns an object:
vt
: The visibility timeout for the queue in secondsdelay
: The delay for new messages in secondsmaxsize
: The maximum size of a message in bytestotalrecv
: Total number of messages received from the queuetotalsent
: Total number of messages sent to the queuecreated
: Timestamp (epoch in seconds) when the queue was createdmodified
: Timestamp (epoch in seconds) when the queue was last modified with setQueueAttributes
msgs
: Current number of messages in the queuehiddenmsgs
: Current number of hidden / not visible messages. A message can be hidden while "in flight" due to a vt
parameter or when sent with a delay
listQueues
List all queues
Returns an array:
popMessage
Receive the next message from the queue and delete it.
Important: This method deletes the message it receives right away. There is no way to receive the message again if something goes wrong while working on the message.
Parameters:
qname
(String): The Queue name.
Returns an object:
message
: The message's contents.id
: The internal message id.sent
: Timestamp of when this message was sent / created.fr
: Timestamp of when this message was first received.rc
: Number of times this message was received.
Note: Will return an empty object if no message is there
receiveMessage
Receive the next message from the queue.
Parameters:
qname
(String): The Queue name.vt
(Number): optional (Default: queue settings) The length of time, in seconds, that the received message will be invisible to others. Allowed values: 0-9999999 (around 115 days)
Returns an object:
message
: The message's contents.id
: The internal message id.sent
: Timestamp of when this message was sent / created.fr
: Timestamp of when this message was first received.rc
: Number of times this message was received.
Note: Will return an empty object if no message is there
sendMessage
Sends a new message.
Parameters:
qname
(String)message
(String)delay
(Number): optional (Default: queue settings) The time in seconds that the delivery of the message will be delayed. Allowed values: 0-9999999 (around 115 days)
Returns:
setQueueAttributes
Sets queue parameters.
Parameters:
qname
(String): The Queue name.vt
(Number): optional * The length of time, in seconds, that a message received from a queue will be invisible to other receiving components when they ask to receive messages. Allowed values: 0-9999999 (around 115 days)delay
(Number): optional The time in seconds that the delivery of all new messages in the queue will be delayed. Allowed values: 0-9999999 (around 115 days)maxsize
(Number): optional The maximum message size in bytes. Allowed values: 1024-65536 and -1 (for unlimited size)
Note: At least one attribute (vt, delay, maxsize) must be supplied. Only attributes that are supplied will be modified.
Returns an object:
-
vt
: The visibility timeout for the queue in seconds
-
delay
: The delay for new messages in seconds
-
maxsize
: The maximum size of a message in bytes
-
totalrecv
: Total number of messages received from the queue
-
totalsent
: Total number of messages sent to the queue
-
created
: Timestamp (epoch in seconds) when the queue was created
-
modified
: Timestamp (epoch in seconds) when the queue was last modified with setQueueAttributes
-
msgs
: Current number of messages in the queue
-
hiddenmsgs
: Current number of hidden / not visible messages. A message can be hidden while "in flight" due to a vt
parameter or when sent with a delay
quit
Disconnect the redis client.
This is only useful if you are using rsmq within a script and want node to be able to exit.
Realtime
When initializing RSMQ you can enable the realtime PUBLISH for new messages. On every new message that gets sent to RSQM via sendMessage
a Redis PUBLISH will be issued to {rsmq.ns}:rt:{qname}
.
Example for RSMQ with default settings:
- The queue
testQueue
already contains 5 messages. - A new message is being sent to the queue
testQueue
. - The following Redis command will be issued:
PUBLISH rsmq:rt:testQueue 6
How to use the realtime option
Besides the PUBLISH when a new message is sent to RSMQ nothing else will happen. Your app could use the Redis SUBSCRIBE command to be notified of new messages and issue a receiveMessage
then. However make sure not to listen with multiple workers for new messages with SUBSCRIBE to prevent multiple simultaneous receiveMessage
calls.
Changes
see the CHANGELOG
Other projects
The MIT License
Please see the LICENSE.md file.