Add Redis Ring.

ring_test.go

@@ -0,0 +1,84 @@
+package redis_test
+
+import (
+	"fmt"
+	"time"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"gopkg.in/redis.v3"
+)
+
+var _ = Describe("Redis ring", func() {
+	var ring *redis.Ring
+
+	setRingKeys := func() {
+		for i := 0; i < 100; i++ {
+			err := ring.Set(fmt.Sprintf("key%d", i), "value", 0).Err()
+			Expect(err).NotTo(HaveOccurred())
+		}
+	}
+
+	BeforeEach(func() {
+		ring = redis.NewRing(&redis.RingOptions{
+			Addrs: map[string]string{
+				"ringShard1": ":" + ringShard1Port,
+				"ringShard2": ":" + ringShard2Port,
+			},
+		})
+
+		// Shards should not have any keys.
+		Expect(ringShard1.FlushDb().Err()).NotTo(HaveOccurred())
+		Expect(ringShard1.Info().Val()).NotTo(ContainSubstring("keys="))
+
+		Expect(ringShard2.FlushDb().Err()).NotTo(HaveOccurred())
+		Expect(ringShard2.Info().Val()).NotTo(ContainSubstring("keys="))
+	})
+
+	AfterEach(func() {
+		Expect(ring.Close()).NotTo(HaveOccurred())
+	})
+
+	It("uses both shards", func() {
+		setRingKeys()
+
+		// Both shards should have some keys now.
+		Expect(ringShard1.Info().Val()).To(ContainSubstring("keys=57"))
+		Expect(ringShard2.Info().Val()).To(ContainSubstring("keys=43"))
+	})
+
+	It("uses one shard when other shard is down", func() {
+		// Stop ringShard2.
+		Expect(ringShard2.Close()).NotTo(HaveOccurred())
+
+		// Ring needs 5 * heartbeat time to detect that node is down.
+		// Give it more to be sure.
+		heartbeat := 100 * time.Millisecond
+		time.Sleep(5*heartbeat + heartbeat)
+
+		setRingKeys()
+
+		// RingShard1 should have all keys.
+		Expect(ringShard1.Info().Val()).To(ContainSubstring("keys=100"))
+
+		// Start ringShard2.
+		var err error
+		ringShard2, err = startRedis(ringShard2Port)
+		Expect(err).NotTo(HaveOccurred())
+
+		// Wait for ringShard2 to come up.
+		Eventually(func() error {
+			return ringShard2.Ping().Err()
+		}, "1s").ShouldNot(HaveOccurred())
+
+		// Ring needs heartbeat time to detect that node is up.
+		// Give it more to be sure.
+		time.Sleep(heartbeat + heartbeat)
+
+		setRingKeys()
+
+		// RingShard2 should have its keys.
+		Expect(ringShard2.Info().Val()).To(ContainSubstring("keys=43"))
+	})
+})