Go-Hasql

https://github.com/yandex/go-hasql
Admin
go-hasql provides a simple and reliable way to access high-availability database setups with...
Tokens:795
Snippets:9
Trust Score:10
License:Apache-2.0
Update:1 year ago
Show doc for...
Tokens:
Raw
### Installing hasql Go Package

Source: https://github.com/yandex/go-hasql/blob/master/README.md

Shows the command-line instruction to install the `hasql/v2` package using `go get`. This is an alternative installation method for direct package installation.

```Console
$ go get -u golang.yandex/hasql/v2
```

--------------------------------

### Creating and Using a hasql Cluster

Source: https://github.com/yandex/go-hasql/blob/master/README.md

Illustrates the core usage of `hasql` by setting up a cluster with static node discovery, checking for a primary node, and pinging it. It demonstrates how to integrate `hasql` with standard `database/sql` connections and handle errors.

```Go
dbFoo, _ := sql.Open("pgx", "host=foo")
dbBar, _ := sql.Open("pgx", "host=bar")

discoverer := NewStaticNodeDiscoverer(
    NewNode("foo", dbFoo),
    NewNode("bar", dbBar),
)

cl, err := hasql.NewCluster(discoverer, hasql.PostgreSQLChecker)
if err != nil { ... }

node := cl.Primary()
if node == nil {
    err := cl.Err() // most recent errors for all nodes in the cluster
}

fmt.Printf("got node %s\n", node)

ctx, cancel := context.WithTimeout(context.Background(), time.Second)
defer cancel()

if err = node.DB().PingContext(ctx); err != nil { ... }
```

--------------------------------

### Importing hasql Go Module

Source: https://github.com/yandex/go-hasql/blob/master/README.md

Demonstrates how to import the `hasql/v2` package into a Go project when using Go modules. This allows `go build`, `go run`, or `go test` to automatically fetch necessary dependencies.

```Go
import "golang.yandex/hasql/v2"
```

--------------------------------

### Selecting Any Alive Node

Source: https://github.com/yandex/go-hasql/blob/master/README.md

Demonstrates how to retrieve any alive primary or standby node from the `hasql` cluster using the `hasql.Alive` criterion. Returns `nil` if no such node is available.

```Go
node := c.Node(hasql.Alive)
```

--------------------------------

### Selecting Node Preferring Primary

Source: https://github.com/yandex/go-hasql/blob/master/README.md

Demonstrates how to retrieve an alive primary node, or an alive standby node if no primary is available, from the `hasql` cluster using the `hasql.PreferPrimary` criterion.

```Go
node := c.Node(hasql.PreferPrimary)
```

--------------------------------

### Selecting Node Preferring Standby

Source: https://github.com/yandex/go-hasql/blob/master/README.md

Shows how to retrieve an alive standby node, or an alive primary node if no standby is available, from the `hasql` cluster using the `hasql.PreferStandby` criterion.

```Go
node := c.Node(hasql.PreferStandby)
```

--------------------------------

### Selecting an Alive Primary Node

Source: https://github.com/yandex/go-hasql/blob/master/README.md

Shows how to retrieve an alive primary node from the `hasql` cluster using the `hasql.Primary` criterion. Returns `nil` if no primary node is available.

```Go
node := c.Node(hasql.Primary)
```

--------------------------------

### Selecting an Alive Standby Node

Source: https://github.com/yandex/go-hasql/blob/master/README.md

Illustrates how to retrieve an alive standby node from the `hasql` cluster using the `hasql.Standby` criterion. Returns `nil` if no standby node is available.

```Go
node := c.Node(hasql.Standby)
```

--------------------------------

### Configuring Cluster with Latency Node Picker

Source: https://github.com/yandex/go-hasql/blob/master/README.md

Illustrates how to configure a `hasql` cluster to use a custom node picker, specifically `LatencyNodePicker`, which selects the node with the lowest latency. This overrides the default random node selection behavior.

```Go
cl, err := hasql.NewCluster(
    hasql.NewStaticNodeDiscoverer(hasql.NewNode("foo", dbFoo), hasql.NewNode("bar", dbBar)),
    hasql.PostgreSQLChecker,
    hasql.WithNodePicker(new(hasql.LatencyNodePicker[*sql.DB])),
)
```
Tokens:
Raw