3.0 KiB
go-dqlite 
This repository provides the go-dqlite Go package, containing bindings for the
dqlite C library and a pure-Go
client for the dqlite wire protocol.
Usage
The best way to understand how to use the go-dqlite package is probably by
looking at the source code of the demo
program and
use it as example.
Build
In order to use the go-dqlite package in your application, you'll need to have
the dqlite C library installed on your
system, along with its dependencies. You then need to pass the -tags
argument to the Go tools when building or testing your packages, for example:
go build -tags libsqlite3
go test -tags libsqlite3
Documentation
The documentation for this package can be found on Godoc.
Demo
To see dqlite in action, either install the Debian package from the PPA:
sudo add-apt-repository -y ppa:dqlite/v1
sudo apt install dqlite
or build the dqlite C library and its dependencies from source, as described here, and then run:
go install -tags libsqlite3 ./cmd/dqlite-demo
from the top-level directory of this repository.
Once the dqlite-demo binary is installed, start three nodes of the demo
application, respectively with IDs 1, 2, and 3:
dqlite-demo start 1 &
dqlite-demo start 2 &
dqlite-demo start 3 &
The node with ID 1 automatically becomes the leader of a single node
cluster, while the nodes with IDs 2 and 3 are waiting to be notified
what cluster they belong to. Let's make nodes 2 and 3 join the
cluster:
dqlite-demo add 2
dqlite-demo add 3
Now we can start using the cluster. The demo application is just a simple key/value store that stores data in a SQLite table. Let's insert a key pair:
dqlite-demo update my-key my-value
and then retrive it from the database:
dqlite-demo query my-key
Currently node 1 is the leader. If we stop it and then try to query the
key again we'll notice that the query command hangs for a bit waiting for
the failover to occur and for another node to step up as leader:
kill -TERM %1; sleep 0.1; dqlite-demo query my-key