feat(eventstore): increase parallel write capabilities (#5940)

This implementation increases parallel write capabilities of the eventstore.
Please have a look at the technical advisories: [05](https://zitadel.com/docs/support/advisory/a10005) and  [06](https://zitadel.com/docs/support/advisory/a10006).
The implementation of eventstore.push is rewritten and stored events are migrated to a new table `eventstore.events2`.
If you are using cockroach: make sure that the database user of ZITADEL has `VIEWACTIVITY` grant. This is used to query events.

internal/eventstore/eventstore_bench_test.go

@@ -0,0 +1,162 @@
+package eventstore_test
+
+import (
+	"context"
+	_ "embed"
+	"fmt"
+	"strconv"
+	"testing"
+
+	"github.com/zitadel/zitadel/internal/eventstore"
+)
+
+//go:embed bench_payload.txt
+var text string
+
+func Benchmark_Push_SameAggregate(b *testing.B) {
+	ctx := context.Background()
+
+	smallPayload := struct {
+		Username  string
+		Firstname string
+		Lastname  string
+	}{
+		Username:  "username",
+		Firstname: "firstname",
+		Lastname:  "lastname",
+	}
+
+	bigPayload := struct {
+		Username  string
+		Firstname string
+		Lastname  string
+		Text      string
+	}{
+		Username:  "username",
+		Firstname: "firstname",
+		Lastname:  "lastname",
+		Text:      text,
+	}
+
+	commands := map[string][]eventstore.Command{
+		"no payload one command": {
+			generateCommand(eventstore.AggregateType(b.Name()), "id"),
+		},
+		"small payload one command": {
+			generateCommand(eventstore.AggregateType(b.Name()), "id", withTestData(smallPayload)),
+		},
+		"big payload one command": {
+			generateCommand(eventstore.AggregateType(b.Name()), "id", withTestData(bigPayload)),
+		},
+		"no payload multiple commands": {
+			generateCommand(eventstore.AggregateType(b.Name()), "id"),
+			generateCommand(eventstore.AggregateType(b.Name()), "id"),
+			generateCommand(eventstore.AggregateType(b.Name()), "id"),
+		},
+		"mixed payload multiple command": {
+			generateCommand(eventstore.AggregateType(b.Name()), "id", withTestData(smallPayload)),
+			generateCommand(eventstore.AggregateType(b.Name()), "id", withTestData(bigPayload)),
+			generateCommand(eventstore.AggregateType(b.Name()), "id", withTestData(smallPayload)),
+			generateCommand(eventstore.AggregateType(b.Name()), "id", withTestData(bigPayload)),
+		},
+	}
+
+	for cmdsKey, cmds := range commands {
+		for pusherKey, store := range pushers {
+			b.Run(fmt.Sprintf("Benchmark_Push_SameAggregate-%s-%s", pusherKey, cmdsKey), func(b *testing.B) {
+				b.StopTimer()
+				cleanupEventstore(clients[pusherKey])
+				b.StartTimer()
+
+				for n := 0; n < b.N; n++ {
+					_, err := store.Push(ctx, cmds...)
+					if err != nil {
+						b.Error(err)
+					}
+				}
+			})
+		}
+	}
+}
+
+func Benchmark_Push_MultipleAggregate_Parallel(b *testing.B) {
+	smallPayload := struct {
+		Username  string
+		Firstname string
+		Lastname  string
+	}{
+		Username:  "username",
+		Firstname: "firstname",
+		Lastname:  "lastname",
+	}
+
+	bigPayload := struct {
+		Username  string
+		Firstname string
+		Lastname  string
+		Text      string
+	}{
+		Username:  "username",
+		Firstname: "firstname",
+		Lastname:  "lastname",
+		Text:      text,
+	}
+
+	commandCreators := map[string]func(id string) []eventstore.Command{
+		"no payload one command": func(id string) []eventstore.Command {
+			return []eventstore.Command{
+				generateCommand(eventstore.AggregateType(b.Name()), id),
+			}
+		},
+		"small payload one command": func(id string) []eventstore.Command {
+			return []eventstore.Command{
+				generateCommand(eventstore.AggregateType(b.Name()), id, withTestData(smallPayload)),
+			}
+		},
+		"big payload one command": func(id string) []eventstore.Command {
+			return []eventstore.Command{
+				generateCommand(eventstore.AggregateType(b.Name()), id, withTestData(bigPayload)),
+			}
+		},
+		"no payload multiple commands": func(id string) []eventstore.Command {
+			return []eventstore.Command{
+				generateCommand(eventstore.AggregateType(b.Name()), id),
+				generateCommand(eventstore.AggregateType(b.Name()), id),
+				generateCommand(eventstore.AggregateType(b.Name()), id),
+			}
+		},
+		"mixed payload multiple command": func(id string) []eventstore.Command {
+			return []eventstore.Command{
+				generateCommand(eventstore.AggregateType(b.Name()), id, withTestData(smallPayload)),
+				generateCommand(eventstore.AggregateType(b.Name()), id, withTestData(bigPayload)),
+				generateCommand(eventstore.AggregateType(b.Name()), id, withTestData(smallPayload)),
+				generateCommand(eventstore.AggregateType(b.Name()), id, withTestData(bigPayload)),
+			}
+		},
+	}
+
+	for cmdsKey, commandCreator := range commandCreators {
+		for pusherKey, store := range pushers {
+			b.Run(fmt.Sprintf("Benchmark_Push_DifferentAggregate-%s-%s", cmdsKey, pusherKey), func(b *testing.B) {
+				b.StopTimer()
+				cleanupEventstore(clients[pusherKey])
+
+				ctx, cancel := context.WithCancel(context.Background())
+				b.StartTimer()
+
+				i := 0
+
+				b.RunParallel(func(p *testing.PB) {
+					for p.Next() {
+						i++
+						_, err := store.Push(ctx, commandCreator(strconv.Itoa(i))...)
+						if err != nil {
+							b.Error(err)
+						}
+					}
+				})
+				cancel()
+			})
+		}
+	}
+}