README
¶
[Archived repo] clustersql 
This project is archived, I myself am not using it any more.
Go Clustering SQL Driver - A clustering, implementation-agnostic "meta"-driver for any backend implementing "database/sql/driver".
It does (latency-based) load-balancing and error-recovery over all registered nodes.
It is assumed that database-state is transparently replicated over all nodes by some database-side clustering solution. This driver ONLY handles the client side of such a cluster.
This package simply multiplexes the driver.Open() function of sql/driver to every attached node. The function is called on each node, returning the first successfully opened connection. (Any connections opening subsequently will be closed.) If opening does not succeed for any node, the latest error gets returned. Any other errors will be masked by default. However, any given latest error for any attached node will remain exposed through expvar, as well as some basic counters and timestamps.
To make use of this kind of clustering, use this package with any backend driver implementing "database/sql/driver" like so:
import "database/sql"
import "github.com/go-sql-driver/mysql"
import "github.com/benthor/clustersql"
There is currently no way around instanciating the backend driver explicitly
mysqlDriver := mysql.MySQLDriver{}
You can perform backend-driver specific settings such as
err := mysql.SetLogger(mylogger)
Create a new clustering driver with the backend driver
clusterDriver := clustersql.NewDriver(mysqlDriver)
Add nodes, including driver-specific name format, in this case Go-MySQL DSN. Here, we add three nodes belonging to a galera cluster
clusterDriver.AddNode("galera1", "user:password@tcp(dbhost1:3306)/db")
clusterDriver.AddNode("galera2", "user:password@tcp(dbhost2:3306)/db")
clusterDriver.AddNode("galera3", "user:password@tcp(dbhost3:3306)/db")
Make the clusterDriver available to the go sql interface under an arbitrary name
sql.Register("myCluster", clusterDriver)
Open the registered clusterDriver with an arbitrary DSN string (not used)
db, err := sql.Open("myCluster", "whatever")
Continue to use the sql interface as documented at http://golang.org/pkg/database/sql/
Before using this in production, you should configure your cluster details in config.toml and run
go test -v .
Note however, that non-failure of the above is no guarantee for a correctly set-up cluster.
Documentation
¶
Overview ¶
Package clustersql is an SQL "meta"-Driver - A clustering, implementation- agnostic wrapper for any backend implementing "database/sql/driver".
It does (latency-based) load-balancing and error-recovery over the registered set of nodes.
It is assumed that database-state is transparently replicated over all nodes by some database-side clustering solution. This driver ONLY handles the client side of such a cluster.
This package simply multiplexes the driver.Open() function of sql/driver to every attached node. The function is called on each node, returning the first successfully opened connection. (Any connections opening subsequently will be closed.) If opening does not succeed for any node, the latest error gets returned. Any other errors will be masked by default. However, any given latest error for any attached node will remain exposed through expvar, as well as some basic counters and timestamps.
To make use of this kind of clustering, use this package with any backend driver implementing "database/sql/driver" like so:
import "database/sql" import "github.com/go-sql-driver/mysql" import "github.com/benthor/clustersql"
There is currently no way around instanciating the backend driver explicitly
mysqlDriver := mysql.MySQLDriver{}
You can perform backend-driver specific settings such as
err := mysql.SetLogger(mylogger)
Create a new clustering driver with the backend driver
clusterDriver := clustersql.NewDriver(mysqlDriver)
Add nodes, including driver-specific name format, in this case Go-MySQL DSN. Here, we add three nodes belonging to a galera (https://mariadb.com/kb/en/mariadb/documentation/replication-cluster-multi-master/galera/) cluster
clusterDriver.AddNode("galera1", "user:password@tcp(dbhost1:3306)/db")
clusterDriver.AddNode("galera2", "user:password@tcp(dbhost2:3306)/db")
clusterDriver.AddNode("galera3", "user:password@tcp(dbhost3:3306)/db")
Make the clusterDriver available to the go sql interface under an arbitrary name
sql.Register("myCluster", clusterDriver)
Open the registered clusterDriver with an arbitrary DSN string (not used)
db, err := sql.Open("myCluster", "whatever")
Continue to use the sql interface as documented at http://golang.org/pkg/database/sql/
Before using this in production, you should configure your cluster details in config.toml and run
go test -v .
Note however, that non-failure of the above is no guarantee for a correctly set-up cluster.
Finally, you SHOULD set db.MaxIdleConns and db.MaxOpenConns to a non-zero value. Although the sql driver usually does a good job of doing its own pooling, file descriptors can leak in corner cases (of which this library might constitue an example).
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Driver ¶
type Driver struct {
// contains filtered or unexported fields
}
func (*Driver) DelNode ¶
DelNode unregisters a named Node from the upstream Driver. This SHOULD(TM) be non-invasive, allowing all pending SQL actions on that node to complete as expected
Source Files