// FindWorkerTablet will:
// - find a rdonly instance in the keyspace / shard
// - mark it as worker
// - tag it with our worker process
func FindWorkerTablet(ctx context.Context, wr *wrangler.Wrangler, cleaner *wrangler.Cleaner, cell, keyspace, shard string) (*topodatapb.TabletAlias, error) {
tabletAlias, err := FindHealthyRdonlyEndPoint(ctx, wr, cell, keyspace, shard)
if err != nil {
return nil, err
}
// We add the tag before calling ChangeSlaveType, so the destination
// vttablet reloads the worker URL when it reloads the tablet.
ourURL := servenv.ListeningURL.String()
wr.Logger().Infof("Adding tag[worker]=%v to tablet %v", ourURL, topoproto.TabletAliasString(tabletAlias))
shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
_, err = wr.TopoServer().UpdateTabletFields(shortCtx, tabletAlias, func(tablet *topodatapb.Tablet) error {
if tablet.Tags == nil {
tablet.Tags = make(map[string]string)
}
tablet.Tags["worker"] = ourURL
return nil
})
cancel()
if err != nil {
return nil, err
}
// Using "defer" here because we remove the tag *before* calling
// ChangeSlaveType back, so we need to record this tag change after the change
// slave type change in the cleaner.
defer wrangler.RecordTabletTagAction(cleaner, tabletAlias, "worker", "")
wr.Logger().Infof("Changing tablet %v to '%v'", topoproto.TabletAliasString(tabletAlias), topodatapb.TabletType_WORKER)
shortCtx, cancel = context.WithTimeout(ctx, *remoteActionsTimeout)
err = wr.ChangeSlaveType(shortCtx, tabletAlias, topodatapb.TabletType_WORKER)
cancel()
if err != nil {
return nil, err
}
// Record a clean-up action to take the tablet back to rdonly.
// We will alter this one later on and let the tablet go back to
// 'spare' if we have stopped replication for too long on it.
wrangler.RecordChangeSlaveTypeAction(cleaner, tabletAlias, topodatapb.TabletType_RDONLY)
return tabletAlias, nil
}
// FindWorkerTablet will:
// - find a rdonly instance in the keyspace / shard
// - mark it as worker
// - tag it with our worker process
func FindWorkerTablet(ctx context.Context, wr *wrangler.Wrangler, cleaner *wrangler.Cleaner, tsc *discovery.TabletStatsCache, cell, keyspace, shard string, minHealthyRdonlyTablets int) (*topodatapb.TabletAlias, error) {
tabletAlias, err := FindHealthyRdonlyTablet(ctx, wr, tsc, cell, keyspace, shard, minHealthyRdonlyTablets)
if err != nil {
return nil, err
}
// We add the tag before calling ChangeSlaveType, so the destination
// vttablet reloads the worker URL when it reloads the tablet.
ourURL := servenv.ListeningURL.String()
wr.Logger().Infof("Adding tag[worker]=%v to tablet %v", ourURL, topoproto.TabletAliasString(tabletAlias))
shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
_, err = wr.TopoServer().UpdateTabletFields(shortCtx, tabletAlias, func(tablet *topodatapb.Tablet) error {
if tablet.Tags == nil {
tablet.Tags = make(map[string]string)
}
tablet.Tags["worker"] = ourURL
tablet.Tags["drain_reason"] = "Used by vtworker"
return nil
})
cancel()
if err != nil {
return nil, err
}
// Using "defer" here because we remove the tag *before* calling
// ChangeSlaveType back, so we need to record this tag change after the change
// slave type change in the cleaner.
defer wrangler.RecordTabletTagAction(cleaner, tabletAlias, "worker", "")
defer wrangler.RecordTabletTagAction(cleaner, tabletAlias, "drain_reason", "")
wr.Logger().Infof("Changing tablet %v to '%v'", topoproto.TabletAliasString(tabletAlias), topodatapb.TabletType_DRAINED)
shortCtx, cancel = context.WithTimeout(ctx, *remoteActionsTimeout)
err = wr.ChangeSlaveType(shortCtx, tabletAlias, topodatapb.TabletType_DRAINED)
cancel()
if err != nil {
return nil, err
}
// Record a clean-up action to take the tablet back to rdonly.
wrangler.RecordChangeSlaveTypeAction(cleaner, tabletAlias, topodatapb.TabletType_DRAINED, topodatapb.TabletType_RDONLY)
return tabletAlias, nil
}
