Merge pull request #75 from ydb-platform/multiple-databases

v3.7.0: Scripting, connection TTL, replacement of database/token, PreferLocations, refactoring

Author: asmyasnikov

CHANGELOG.md

@@ -1,3 +1,17 @@
+## 3.7.0
+* Replaced `Option` to `CustomOption` on `Connection` interface methods
+* Implements `WithCustom[Token,Database]` options for redefine database and token
+* Removed experimental `balancer.PreferEndpoints[WithFallback][RegEx]` balancers
+* Supported connections `TTL` with `Option` `WithConnectionTTL`
+* Remove unnecessary `WithFastDial` option (lazy connections are always fast inserts into cluster)
+* Added `Scripting` service client with API methods `Execute()`, `StreamExecute()` and `Explain()`
+* Added `String()` method to `table.types.Type` interface
+* Added `With[Custom]UserAgent()` `Option` and `CustomOption` constructors
+* Refactored `log.Logger` interface and internal implementation
+* Added `retry.RetryableError()` for returns user-defined error which must be retryed 
+* Renamed internal type `internal.errors.OperationCompleted` to `internal.errors.OperationStatus`
+* Added `String()` method to `table.KeyRange` and `table.Value` types
+
 ## 3.6.2
 * Refactored table retry helpers
 * Added new `PreferLocations[WithFallback][RegEx]` balancers

balancer/balancer.go

@@ -0,0 +1,114 @@
+package balancer
+
+import (
+	"strings"
+
+	"github.com/ydb-platform/ydb-go-sdk/v3/internal/balancer/ibalancer"
+	"github.com/ydb-platform/ydb-go-sdk/v3/internal/balancer/multi"
+	"github.com/ydb-platform/ydb-go-sdk/v3/internal/balancer/rr"
+	"github.com/ydb-platform/ydb-go-sdk/v3/internal/balancer/single"
+	"github.com/ydb-platform/ydb-go-sdk/v3/internal/conn"
+)
+
+func RoundRobin() ibalancer.Balancer {
+	return rr.RoundRobin()
+}
+
+func RandomChoice() ibalancer.Balancer {
+	return rr.RandomChoice()
+}
+
+func SingleConn() ibalancer.Balancer {
+	return single.Balancer()
+}
+
+// PreferLocalDC creates balancer which use endpoints only in location such as initial endpoint location
+// Balancer "balancer" defines balancing algorithm between endpoints selected with filter by location
+func PreferLocalDC(balancer ibalancer.Balancer) ibalancer.Balancer {
+	return multi.Balancer(
+		multi.WithBalancer(
+			balancer,
+			func(cc conn.Conn) bool {
+				return cc.Endpoint().LocalDC()
+			},
+		),
+	)
+}
+
+// PreferLocalDCWithFallBack creates balancer which use endpoints only in location such as initial endpoint location
+// Balancer "balancer" defines balancing algorithm between endpoints selected with filter by location
+// If filter returned zero endpoints from all discovery endpoints list - used all endpoint instead
+func PreferLocalDCWithFallBack(balancer ibalancer.Balancer) ibalancer.Balancer {
+	return multi.Balancer(
+		multi.WithBalancer(
+			balancer,
+			func(cc conn.Conn) bool {
+				return cc.Endpoint().LocalDC()
+			},
+		),
+		multi.WithBalancer(
+			balancer.(ibalancer.Creator).Create(),
+			func(cc conn.Conn) bool {
+				return !cc.Endpoint().LocalDC()
+			},
+		),
+	)
+}
+
+// PreferLocations creates balancer which use endpoints only in selected locations (such as "MAN", "VLA", etc.)
+// Balancer "balancer" defines balancing algorithm between endpoints selected with filter by location
+func PreferLocations(balancer ibalancer.Balancer, locations ...string) ibalancer.Balancer {
+	if len(locations) == 0 {
+		panic("empty list of locations")
+	}
+	for i := range locations {
+		locations[i] = strings.ToUpper(locations[i])
+	}
+	return multi.Balancer(
+		multi.WithBalancer(balancer, func(cc conn.Conn) bool {
+			location := strings.ToUpper(cc.Endpoint().Location())
+			for _, l := range locations {
+				if location == l {
+					return true
+				}
+			}
+			return false
+		}),
+	)
+}
+
+// PreferLocationsWithFallback creates balancer which use endpoints only in selected locations
+// Balancer "balancer" defines balancing algorithm between endpoints selected with filter by location
+// If filter returned zero endpoints from all discovery endpoints list - used all endpoint instead
+func PreferLocationsWithFallback(balancer ibalancer.Balancer, locations ...string) ibalancer.Balancer {
+	if len(locations) == 0 {
+		panic("empty list of locations")
+	}
+	for i := range locations {
+		locations[i] = strings.ToUpper(locations[i])
+	}
+	return multi.Balancer(
+		multi.WithBalancer(balancer, func(cc conn.Conn) bool {
+			location := strings.ToUpper(cc.Endpoint().Location())
+			for _, l := range locations {
+				if location == l {
+					return true
+				}
+			}
+			return false
+		}),
+		multi.WithBalancer(balancer.(ibalancer.Creator).Create(), func(cc conn.Conn) bool {
+			location := strings.ToUpper(cc.Endpoint().Location())
+			for _, l := range locations {
+				if location == l {
+					return false
+				}
+			}
+			return true
+		}),
+	)
+}
+
+func Default() ibalancer.Balancer {
+	return PreferLocalDCWithFallBack(RandomChoice())
+}