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NSQ is a realtime message processing system designed to operate at bitly's scale, handling
billions of messages per day.
It promotes distributed and decentralized topologies without single points of failure,
enabling fault tolerance and high availability coupled with a reliable message delivery
guarantee.
Operationally, NSQ is easy to configure and deploy (all parameters are specified on the command
line and compiled binaries have no runtime dependencies). For maximum flexibility, it is agnostic to
data format (messages can be JSON, MsgPack, Protocol Buffers, or anything
else). Official Go and Python libraries are available out of the box and, if you're interested in
building your own client, there's a protocol spec (see client libraries).
The latest stable release is 0.2.16. We publish binary releases for
linux and darwin.
NOTE: master is our development branch and may not be stable at all times.
Why?
NSQ was built as a successor to simplequeue (part of simplehttp)
and as such was designed to (in no particular order):
- provide easy topology solutions that enable high-availability and eliminate SPOFs
- address the need for stronger message delivery guarantees
- bound the memory footprint of a single process (by persisting some messages to disk)
- greatly simplify configuration requirements for producers and consumers
- provide a straightforward upgrade path
- improve efficiency
If you're interested in more of the design, history, and evolution please read our design
doc or blog post.
Client Libraries
Additional Documentation
NSQ is composed of the following individual components, each with their own README:
- nsqd is the daemon that receives, buffers, and delivers messages to clients.
- nsqlookupd is the daemon that manages topology information
- nsqadmin is the web UI to view message statistics and perform administrative tasks
- nsq is a go package for writing
nsqd
clients
As well as the following documents in the docs directory:
- Design - in-depth overview of how and why
- Patterns - implementation solutions for various use cases
- Protocol Spec - technical details for the
nsqd
protocol
DISCLAIMER: Please keep in mind that NSQ is designed to be used in a distributed fashion. Single
node performance is important, but not the end-all-be-all of what we're looking to achieve. Also,
benchmarks are stupid, but here's a few anyway to ignite the flame:
On a 2012 MacBook Air i7 2ghz (GOMAXPROCS=1
, go tip 8bbc0bdf832e
) single publisher, single consumer:
$ ./nsqd --mem-queue-size=100000
$ ./bench_writer --num=100000
2013/01/06 17:24:38 duration: 310.575793ms - 61.413mb/s - 321982.596ops/s - 3.106us/op
$ ./bench_reader --num=100000
2013/01/06 17:25:47 duration: 672.059087ms - 28.381mb/s - 148796.441ops/s - 6.721us/op
Getting Started
The following steps will run NSQ on your local machine and walk through publishing, consuming,
and archiving messages to disk.
-
follow the instructions in the INSTALLING doc (or download a binary
release).
-
in one shell, start nsqlookupd
:
$ nsqlookupd
-
in another shell, start nsqd
:
$ nsqd --lookupd-tcp-address=127.0.0.1:4160
-
in another shell, start nsqadmin
:
$ nsqadmin --lookupd-http-address=127.0.0.1:4161
-
publish an initial message (creates the topic in the cluster, too):
$ curl -d 'hello world 1' 'http://127.0.0.1:4151/put?topic=test'
-
finally, in another shell, start nsq_to_file
:
$ nsq_to_file --topic=test --output-dir=/tmp --lookupd-http-address=127.0.0.1:4161
-
publish more messages to nsqd
:
$ curl -d 'hello world 2' 'http://127.0.0.1:4151/put?topic=test'
$ curl -d 'hello world 3' 'http://127.0.0.1:4151/put?topic=test'
-
to verify things worked as expected, in a web browser open http://127.0.0.1:4171/
to view
the nsqadmin
UI and see statistics. Also, check the contents of the log files (test.*.log
)
written to /tmp
.
The important lesson here is that nsq_to_file
(the client) is not explicitly told where the test
topic is produced, it retrieves this information from nsqlookupd
and, despite the timing of the
connection, no messages are lost.
Authors
NSQ was designed and developed by Matt Reiferson (@imsnakes) and Jehiah Czebotar
(@jehiah) but wouldn't have been possible without the support of
bitly:
Contributors