Installing a NATS Server
NATS philosophy is simplicity. Installation is just decompressing a zip file and copying the binary to an appropriate directory; you can also use your favorite package manager. Here's a list of different ways you can install or run NATS:
The following table indicates the current supported NATS server build combinations for operating systems and architectures.
Operating System | Architectures |
|---|---|
Darwin (macOS) | amd64, arm64 |
Linux | amd64, 386, arm6, arm7, arm64, mips64le, s390x |
Windows | amd64, 386, arm6, arm7, arm64 |
FreeBSD | amd64 |
Note, not all installation methods below have distributions for all OS and architecture combinations.
The NATS server itself has minimal hardware requirements to support small edge devices, but can take advantage of more resources if available.
CPU should be considered in accepting TLS connections. After a network partition, every disconnected client will attempt to connect to a NATS server in the cluster simultaneously, so CPU on those servers will momentarily spike. When there are many clients this can be mitigated with reconnect jitter settings, and errors can be reduced with longer TLS timeouts, and scaling up cluster sizes.
We highly recommend testing to see if smaller, cheaper machines suffice for your workload - often they do! We suggest starting here and adjusting resources after load testing specific to your environment. When using cloud provider instance types make sure the node has a sufficient NIC to support the required bandwidth for the application needs.
For high throughput use cases, the network interface card (NIC) or the available bandwidth are often the bottleneck, so ensure the hardware or cloud provider instance types are sufficient for your needs.
The table below notes the minimum number of cores and memory with the different combinations of publishers, subscribers, and message rate where the single server or cluster remained stable (not slow nor hitting an out-of-memory). These were tested inside containers with
GOMEMLIMIT set to 90% of the memory allocation and with a 2021-era CPU and SSD for JetStream storage.All message rates are per second.
Cluster Size | CPU cores | Memory | Subscribers | Publishers | Publish Rate | Total Message Rate |
|---|---|---|---|---|---|---|
1 | 1 | 32 MiB | 1 | 100 | 1000 | 100,000 |
1 | 1 | 64 MiB | 1 | 1000 | 100 | 100,000 |
3 | 1 | 32 MiB | 1 | 1000 | 100 | 100,000 |
3 | 1 | 64 MiB | 1 | 1000 | 100 | 100,000 |
This table follows the same pattern as above, however the published messages are being received by a stream using file storage with the one replica or three (for a cluster size of three). The subscriber is relying on a "pull consumer" for fetching messages.
Cluster Size | CPU cores | Memory | Subscribers | Publishers | Publish Rate | Total Message Rate |
|---|---|---|---|---|---|---|
1 | 1 | 32 MiB | 1 | 10 | 100 | 1,000 |
1 | 1 | 32 MiB | 1 | 100 | 10 | 1,000 |
1 | 1 | 64 MiB | 1 | 100 | 100 | 10,000 |
1 | 1 | 64 MiB | 1 | 1000 | 10 | 10,000 |
3 | 1 | 32 MiB | 1 | 100 | 10 | 1,000 |
3 | 1 | 64 MiB | 1 | 100 | 100 | 10,000 |
3 | 1 | 64 MiB | 1 | 1000 | 10 | 10,000 |
3 | 1 | 256 MiB | 1 | 1000 | 100 | 100,000 |
With Docker you can install the server easily without scattering binaries and other artifacts on your system. The only pre-requisite is to install docker.
docker pull nats:latest
To run NATS on Docker:
docker run -p 4222:4222 -ti nats:latest
[1] 2019/05/24 15:42:58.228063 [INF] Starting nats-server version #.#.#
[1] 2019/05/24 15:42:58.228115 [INF] Git commit [#######]
[1] 2019/05/24 15:42:58.228201 [INF] Starting http monitor on 0.0.0.0:8222
[1] 2019/05/24 15:42:58.228740 [INF] Listening for client connections on 0.0.0.0:4222
[1] 2019/05/24 15:42:58.228765 [INF] Server is ready
[1] 2019/05/24 15:42:58.229003 [INF] Listening for route connections on 0.0.0.0:6222
On Windows:
choco install nats-server
On Mac OS:
brew install nats-server
To test your installation (provided the executable is visible to your shell):
Typing
nats-server should output something like[41634] 2019/05/13 09:42:11.745919 [INF] Starting nats-server version 2.*.*
[41634] 2019/05/13 09:42:11.746240 [INF] Listening for client connections on 0.0.0.0:4222
...
[41634] 2019/05/13 09:42:11.746249 [INF] Server id is NBNYNR4ZNTH4N2UQKSAAKBAFLDV3PZO4OUYONSUIQASTQT7BT4ZF6WX7
[41634] 2019/05/13 09:42:11.746252 [INF] Server is ready
On Linux:
yay nats-server
From the releases page, copy the link to the release archive file of your choice and download it using
curl -L.For example, assuming version X.Y.Z of the server and a Linux AMD64:
curl -L https://github.com/nats-io/nats-server/releases/download/vX.Y.Z/nats-server-vX.Y.Z-linux-amd64.zip -o nats-server.zip
unzip nats-server.zip -d nats-server
Archive: nats-server.zip
creating: nats-server-vX.Y.Z-linux-amd64/
...
and finally:
sudo cp nats-server/nats-server-vX.Y.Z-linux-amd64/nats-server /usr/bin
If you have Go installed, installing the binary is easy:
GO111MODULE=on go get github.com/nats-io/nats-server/v2
This mechanism will install a build of master, which almost certainly will not be a released version. If you are a developer and want to play with the latest, this is the easiest way.
To test your installation (provided the $GOPATH/bin is set) by typing
nats-server which should output something like[41634] 2019/05/13 09:42:11.745919 [INF] Starting nats-server version 2.6.2
[41634] 2019/05/13 09:42:11.746240 [INF] Listening for client connections on 0.0.0.0:4222
...
[41634] 2019/05/13 09:42:11.746249 [INF] Server id is NBNYNR4ZNTH4N2UQKSAAKBAFLDV3PZO4OUYONSUIQASTQT7BT4ZF6WX7
[41634] 2019/05/13 09:42:11.746252 [INF] Server is ready
If you are having issues when using the recent versions of NATS and Go modules such as:
go: github.com/nats-io/[email protected]: parsing go.mod: unexpected module path "github.com/nats-io/nats.go"
go: github.com/nats-io/[email protected]: parsing go.mod: unexpected module path "github.com/nats-io/stan.go"
To fix it:
- 1.Update your
go.modusing the latest tags, for example for both NATS and NATS Streaming clients:
module github.com/wallyqs/hello-nats-go-mod
go 1.12
require (
github.com/nats-io/nats.go v1.8.1
github.com/nats-io/stan.go v0.5.0
)
Or if you want to import the NATS Server v2 to embed it, notice the
/v2 after the nats-server module name. If that is not present, then go modules will not fetch it and would accidentally end up with 1.4.1 version of the server.require (
github.com/nats-io/nats-server/v2 v2.0.0
github.com/nats-io/nats.go v1.8.1
)
If embedding both NATS Streaming and NATS Servers:
require (
github.com/nats-io/nats-server/v2 v2.0.0 // indirect
github.com/nats-io/nats-streaming-server v0.15.1
)
- 1.Next, update the imports within the repo:
find ./ -type f -name "*.go" -exec sed -i -e 's/github.com\/nats-io\/go-nats-streaming/github.com\/nats-io\/stan.go/g' {} \;
find ./ -type f -name "*.go" -exec sed -i -e 's/github.com\/nats-io\/go-nats/github.com\/nats-io\/nats.go/g' {} \;
find ./ -type f -name "*.go" -exec sed -i -e 's/github.com\/nats-io\/gnatsd/github.com\/nats-io\/nats-server\/v2/g' {} \;
find ./ -type f -name "*.go" -exec sed -i -e 's/github.com\/nats-io\/nats-server/github.com\/nats-io\/nats-server\/v2/g' {} \;
- 1.(Recommended) Run Go fmt as the rename will affect the proper ordering of the imports
When using
go get to fetch the client, include an extra slash at the end of the repo. For example:GO111MODULE=on go get github.com/nats-io/nats.go/@latest
GO111MODULE=on go get github.com/nats-io/nats.go/@v1.8.1
When trying to fetch the latest version of the server with
go get, you have to add v2 at the end:GO111MODULE=on go get github.com/nats-io/nats-server/[email protected]
Otherwise,
go get will fetch the v1.4.1 version of the server, which is also named (gnatsd), the previous name for nats-server.GO111MODULE=on go get github.com/nats-io/[email protected]
go: finding github.com/nats-io/gnatsd/server latest
go: finding golang.org/x/crypto/bcrypt latest
go: finding golang.org/x/crypto latest
In order to use an older tag, you will have to use the previous name (gnatsd) otherwise it will result in
go mod parsing errors.# OK
GO111MODULE=on go get github.com/nats-io/go-nats/@v1.7.2
# Not OK
GO111MODULE=on go get github.com/nats-io/nats.go/@v1.7.2
go: finding github.com/nats-io/nats.go v1.7.2
go: downloading github.com/nats-io/nats.go v1.7.2
go: extracting github.com/nats-io/nats.go v1.7.2
go: finding github.com/nats-io/go-nats/encoders/builtin latest
go: finding github.com/nats-io/go-nats/util latest
go: finding github.com/nats-io/go-nats/encoders latest
go: finding github.com/nats-io/go-nats v1.8.1
go: downloading github.com/nats-io/go-nats v1.8.1
go: extracting github.com/nats-io/go-nats v1.8.1
go: github.com/nats-io/[email protected]: parsing go.mod: unexpected module path "github.com/nats-io/nats.go"
go: error loading module requirements