Golang ShardInfo.SourceShards方法代码示例

func (wr *Wrangler) migrateServedFrom(ki *topo.KeyspaceInfo, si *topo.ShardInfo, servedType topo.TabletType, reverse bool) (err error) {

	// re-read and update keyspace info record
	ki, err = wr.ts.GetKeyspace(ki.KeyspaceName())
	if err != nil {
		return err
	}
	if reverse {
		if _, ok := ki.ServedFrom[servedType]; ok {
			return fmt.Errorf("Destination Keyspace %s is not serving type %v", ki.KeyspaceName(), servedType)
		}
		ki.ServedFrom[servedType] = si.SourceShards[0].Keyspace
	} else {
		if _, ok := ki.ServedFrom[servedType]; !ok {
			return fmt.Errorf("Destination Keyspace %s is already serving type %v", ki.KeyspaceName(), servedType)
		}
		delete(ki.ServedFrom, servedType)
	}

	// re-read and check the destination shard
	si, err = wr.ts.GetShard(si.Keyspace(), si.ShardName())
	if err != nil {
		return err
	}
	if len(si.SourceShards) != 1 {
		return fmt.Errorf("Destination shard %v/%v is not a vertical split target", si.Keyspace(), si.ShardName())
	}
	tables := si.SourceShards[0].Tables

	// read the source shard, we'll need its master
	sourceShard, err := wr.ts.GetShard(si.SourceShards[0].Keyspace, si.SourceShards[0].Shard)
	if err != nil {
		return err
	}

	ev := &events.MigrateServedFrom{
		Keyspace:         *ki,
		SourceShard:      *sourceShard,
		DestinationShard: *si,
		ServedType:       servedType,
		Reverse:          reverse,
	}
	event.DispatchUpdate(ev, "start")
	defer func() {
		if err != nil {
			event.DispatchUpdate(ev, "failed: "+err.Error())
		}
	}()

	// For master type migration, need to:
	// - switch the source shard to read-only
	// - gather the replication point
	// - wait for filtered replication to catch up before we continue
	// - disable filtered replication after the fact
	var sourceMasterTabletInfo *topo.TabletInfo
	if servedType == topo.TYPE_MASTER {
		// set master to read-only
		event.DispatchUpdate(ev, "setting source shard master to read-only")
		actionPath, err := wr.ai.SetReadOnly(sourceShard.MasterAlias)
		if err != nil {
			return err
		}
		if err := wr.WaitForCompletion(actionPath); err != nil {
			return err
		}

		// get the position
		event.DispatchUpdate(ev, "getting master position")
		sourceMasterTabletInfo, err = wr.ts.GetTablet(sourceShard.MasterAlias)
		if err != nil {
			return err
		}
		masterPosition, err := wr.ai.MasterPosition(sourceMasterTabletInfo, wr.ActionTimeout())
		if err != nil {
			return err
		}

		// wait for it
		event.DispatchUpdate(ev, "waiting for destination master to catch up to source master")
		if err := wr.ai.WaitBlpPosition(si.MasterAlias, blproto.BlpPosition{
			Uid:      0,
			Position: masterPosition,
		}, wr.ActionTimeout()); err != nil {
			return err
		}

		// and clear the shard record
		si.SourceShards = nil
	}

	// All is good, we can save the keyspace and shard (if needed) now
	event.DispatchUpdate(ev, "updating keyspace")
	if err = topo.UpdateKeyspace(wr.ts, ki); err != nil {
		return err
	}
	event.DispatchUpdate(ev, "updating destination shard")
	if servedType == topo.TYPE_MASTER {
		if err := topo.UpdateShard(wr.ts, si); err != nil {
			return err
		}
//.........这里部分代码省略.........

// masterMigrateServedFrom handles the master migration. The ordering is
// a bit different than for rdonly / replica to guarantee a smooth transition.
//
// The order is as follows:
// - Add BlacklistedTables on the source shard map for master
// - Refresh the source master, so it stops writing on the tables
// - Get the source master position, wait until destination master reaches it
// - Clear SourceShard on the destination Shard
// - Refresh the destination master, so its stops its filtered
//   replication and starts accepting writes
func (wr *Wrangler) masterMigrateServedFrom(ctx context.Context, ki *topo.KeyspaceInfo, sourceShard *topo.ShardInfo, destinationShard *topo.ShardInfo, tables []string, ev *events.MigrateServedFrom, filteredReplicationWaitTime time.Duration) error {
	// Read the data we need
	sourceMasterTabletInfo, err := wr.ts.GetTablet(ctx, sourceShard.MasterAlias)
	if err != nil {
		return err
	}
	destinationMasterTabletInfo, err := wr.ts.GetTablet(ctx, destinationShard.MasterAlias)
	if err != nil {
		return err
	}

	// Update source shard (more blacklisted tables)
	event.DispatchUpdate(ev, "updating source shard")
	if err := sourceShard.UpdateSourceBlacklistedTables(topodatapb.TabletType_MASTER, nil, false, tables); err != nil {
		return fmt.Errorf("UpdateSourceBlacklistedTables(%v/%v) failed: %v", sourceShard.Keyspace(), sourceShard.ShardName(), err)
	}
	if err := wr.ts.UpdateShard(ctx, sourceShard); err != nil {
		return fmt.Errorf("UpdateShard(%v/%v) failed: %v", sourceShard.Keyspace(), sourceShard.ShardName(), err)
	}

	// Now refresh the blacklisted table list on the source master
	event.DispatchUpdate(ev, "refreshing source master so it updates its blacklisted tables")
	if err := wr.tmc.RefreshState(ctx, sourceMasterTabletInfo); err != nil {
		return err
	}

	// get the position
	event.DispatchUpdate(ev, "getting master position")
	masterPosition, err := wr.tmc.MasterPosition(ctx, sourceMasterTabletInfo)
	if err != nil {
		return err
	}

	// wait for it
	event.DispatchUpdate(ev, "waiting for destination master to catch up to source master")
	if err := wr.tmc.WaitBlpPosition(ctx, destinationMasterTabletInfo, &tabletmanagerdatapb.BlpPosition{
		Uid:      0,
		Position: masterPosition,
	}, filteredReplicationWaitTime); err != nil {
		return err
	}

	// Update the destination keyspace (its ServedFrom has changed)
	event.DispatchUpdate(ev, "updating keyspace")
	if err = wr.ts.UpdateKeyspace(ctx, ki); err != nil {
		return err
	}

	// Update the destination shard (no more source shard)
	event.DispatchUpdate(ev, "updating destination shard")
	destinationShard.SourceShards = nil
	if err := wr.ts.UpdateShard(ctx, destinationShard); err != nil {
		return err
	}

	// Tell the new shards masters they can now be read-write.
	// Invoking a remote action will also make the tablet stop filtered
	// replication.
	event.DispatchUpdate(ev, "setting destination shard masters read-write")
	if err := wr.refreshMasters(ctx, []*topo.ShardInfo{destinationShard}); err != nil {
		return err
	}

	return nil
}

func (wr *Wrangler) migrateServedFrom(ki *topo.KeyspaceInfo, si *topo.ShardInfo, servedType topo.TabletType, reverse bool) error {

	// re-read and update keyspace info record
	var err error
	ki, err = wr.ts.GetKeyspace(ki.KeyspaceName())
	if err != nil {
		return err
	}
	if reverse {
		if _, ok := ki.ServedFrom[servedType]; ok {
			return fmt.Errorf("Destination Keyspace %s is not serving type %v", ki.KeyspaceName(), servedType)
		}
		ki.ServedFrom[servedType] = si.SourceShards[0].Keyspace
	} else {
		if _, ok := ki.ServedFrom[servedType]; !ok {
			return fmt.Errorf("Destination Keyspace %s is already serving type %v", ki.KeyspaceName(), servedType)
		}
		delete(ki.ServedFrom, servedType)
	}

	// re-read and check the destination shard
	si, err = wr.ts.GetShard(si.Keyspace(), si.ShardName())
	if err != nil {
		return err
	}
	if len(si.SourceShards) != 1 {
		return fmt.Errorf("Destination shard %v/%v is not a vertical split target", si.Keyspace(), si.ShardName())
	}
	tables := si.SourceShards[0].Tables

	// read the source shard, we'll need its master
	sourceShard, err := wr.ts.GetShard(si.SourceShards[0].Keyspace, si.SourceShards[0].Shard)
	if err != nil {
		return err
	}

	// For master type migration, need to:
	// - switch the source shard to read-only
	// - gather the replication point
	// - wait for filtered replication to catch up before we continue
	// - disable filtered replication after the fact
	var sourceMasterTabletInfo *topo.TabletInfo
	if servedType == topo.TYPE_MASTER {
		// set master to read-only
		actionPath, err := wr.ai.SetReadOnly(sourceShard.MasterAlias)
		if err != nil {
			return err
		}
		if err := wr.ai.WaitForCompletion(actionPath, wr.actionTimeout()); err != nil {
			return err
		}

		// get the position
		sourceMasterTabletInfo, err = wr.ts.GetTablet(sourceShard.MasterAlias)
		if err != nil {
			return err
		}
		masterPosition, err := wr.ai.MasterPosition(sourceMasterTabletInfo, wr.actionTimeout())
		if err != nil {
			return err
		}

		// wait for it
		if err := wr.ai.WaitBlpPosition(si.MasterAlias, myproto.BlpPosition{
			Uid:     0,
			GroupId: masterPosition.MasterLogGroupId,
		}, wr.actionTimeout()); err != nil {
			return err
		}

		// and clear the shard record
		si.SourceShards = nil
	}

	// All is good, we can save the keyspace and shard (if needed) now
	if err = wr.ts.UpdateKeyspace(ki); err != nil {
		return err
	}
	if servedType == topo.TYPE_MASTER {
		if err := wr.ts.UpdateShard(si); err != nil {
			return err
		}
	}

	// Tell the new shards masters they can now be read-write.
	// Invoking a remote action will also make the tablet stop filtered
	// replication.
	if servedType == topo.TYPE_MASTER {
		if err := wr.makeMastersReadWrite([]*topo.ShardInfo{si}); err != nil {
			return err
		}
	}

	// Now blacklist the table list on the right servers
	if servedType == topo.TYPE_MASTER {
		if err := wr.ai.SetBlacklistedTables(sourceMasterTabletInfo, tables, wr.actionTimeout()); err != nil {
			return err
		}
	} else {
		// We use the list of tables that are replicating
//.........这里部分代码省略.........

// masterMigrateServedFrom handles the master migration. The ordering is
// a bit different than for rdonly / replica to guarantee a smooth transition.
//
// The order is as follows:
// - Add BlacklistedTables on the source shard map for master
// - Refresh the source master, so it stops writing on the tables
// - Get the source master position, wait until destination master reaches it
// - Clear SourceShard on the destination Shard
// - Refresh the destination master, so its stops its filtered
//   replication and starts accepting writes
func (wr *Wrangler) masterMigrateServedFrom(ki *topo.KeyspaceInfo, sourceShard *topo.ShardInfo, destinationShard *topo.ShardInfo, servedType topo.TabletType, tables []string, ev *events.MigrateServedFrom) error {
	// Read the data we need
	sourceMasterTabletInfo, err := wr.ts.GetTablet(sourceShard.MasterAlias)
	if err != nil {
		return err
	}
	destinationMasterTabletInfo, err := wr.ts.GetTablet(destinationShard.MasterAlias)
	if err != nil {
		return err
	}

	// Update source shard (more blacklisted tables)
	event.DispatchUpdate(ev, "updating source shard")
	if sourceShard.BlacklistedTablesMap == nil {
		sourceShard.BlacklistedTablesMap = make(map[topo.TabletType][]string)
	}
	sourceShard.BlacklistedTablesMap[servedType] = tables
	if err := topo.UpdateShard(wr.ts, sourceShard); err != nil {
		return err
	}

	// Now refresh the blacklisted table list on the source master
	event.DispatchUpdate(ev, "refreshing source master so it updates its blacklisted tables")
	if err := wr.tmc.RefreshState(sourceMasterTabletInfo, wr.ActionTimeout()); err != nil {
		return err
	}

	// get the position
	event.DispatchUpdate(ev, "getting master position")
	masterPosition, err := wr.tmc.MasterPosition(sourceMasterTabletInfo, wr.ActionTimeout())
	if err != nil {
		return err
	}

	// wait for it
	event.DispatchUpdate(ev, "waiting for destination master to catch up to source master")
	if err := wr.tmc.WaitBlpPosition(destinationMasterTabletInfo, blproto.BlpPosition{
		Uid:      0,
		Position: masterPosition,
	}, wr.ActionTimeout()); err != nil {
		return err
	}

	// Update the destination keyspace (its ServedFrom has changed)
	event.DispatchUpdate(ev, "updating keyspace")
	if err = topo.UpdateKeyspace(wr.ts, ki); err != nil {
		return err
	}

	// Update the destination shard (no more source shard)
	event.DispatchUpdate(ev, "updating destination shard")
	destinationShard.SourceShards = nil
	if err := topo.UpdateShard(wr.ts, destinationShard); err != nil {
		return err
	}

	// Tell the new shards masters they can now be read-write.
	// Invoking a remote action will also make the tablet stop filtered
	// replication.
	event.DispatchUpdate(ev, "setting destination shard masters read-write")
	if err := wr.refreshMasters([]*topo.ShardInfo{destinationShard}); err != nil {
		return err
	}

	return nil
}