fix(mirror): ensure multiple runs (#9899)

1. After second execution, mirror starts to fail because of Primary key
constraints on the events table. Because mirror always took the the
first `system.mirror.succeeded` instead of the newest one
2. Mirror panicked during migration of fields tables

1. Adjusted the database query to order descending and limit 1
2. added missing assignment

- detailed logging if the copy from statement failed.

cmd/mirror/event_store.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"time"
 
+	"github.com/jackc/pgx/v5/pgconn"
 	"github.com/jackc/pgx/v5/stdlib"
 	"github.com/shopspring/decimal"
 	"github.com/spf13/cobra"
@@ -172,6 +173,10 @@ func copyEvents(ctx context.Context, source, dest *db.DB, bulkSize uint32) {
 		tag, err := conn.PgConn().CopyFrom(ctx, reader, "COPY eventstore.events2 FROM STDIN")
 		eventCount = tag.RowsAffected()
 		if err != nil {
+			pgErr := new(pgconn.PgError)
+			errors.As(err, &pgErr)
+
+			logging.WithError(err).WithField("pg_err_details", pgErr.Detail).Error("unable to copy events into destination")
 			return zerrors.ThrowUnknown(err, "MIGRA-DTHi7", "unable to copy events into destination")
 		}
 

cmd/mirror/projections.go

@@ -120,7 +120,10 @@ func projections(
 	logging.OnError(err).Fatal("unable create static storage")
 
 	config.Eventstore.Querier = old_es.NewCRDB(client)
-	config.Eventstore.Pusher = new_es.NewEventstore(client)
+	newES := new_es.NewEventstore(client)
+	config.Eventstore.Pusher = newES
+	config.Eventstore.Searcher = newES
+
 	es := eventstore.NewEventstore(config.Eventstore)
 	esV4 := es_v4.NewEventstoreFromOne(es_v4_pg.New(client, &es_v4_pg.Config{
 		MaxRetries: config.Eventstore.MaxRetries,

internal/v2/readmodel/last_successful_mirror.go

@@ -36,6 +36,7 @@ func (p *LastSuccessfulMirror) Filter() *eventstore.Filter {
 		),
 		eventstore.FilterPagination(
 			eventstore.Descending(),
+			eventstore.Limit(1),
 		),
 	)
 }