satellite/overlay: add AOST to GetParticipatingNodes method

This method is sometimes ends with transaction error. Most probably
because it's trying to do full table scan on nodes table which is
heavily used. Adding AOST should help with DB contention.

Change-Id: Ibd4358d28dc26922b60c6b30862f20e7c0662cd1

satellite/overlay/config.go

@@ -29,6 +29,7 @@ type Config struct {
 	RepairExcludedCountryCodes      []string      `help:"list of country codes to exclude nodes from target repair selection" default:"" testDefault:"FR,BE"`
 	SendNodeEmails                  bool          `help:"whether to send emails to nodes" default:"false"`
 	MinimumNewNodeIDDifficulty      int           `help:"the minimum node id difficulty required for new nodes. existing nodes remain allowed" devDefault:"0" releaseDefault:"36"`
+	AsOfSystemTime                  time.Duration `help:"default AS OF SYSTEM TIME for service" default:"-10s" testDefault:"0"`
 }
 
 // AsOfSystemTimeConfig is a configuration struct to enable 'AS OF SYSTEM TIME' for CRDB queries.

satellite/overlay/service.go

@@ -506,8 +506,7 @@ func (service *Service) GetNodes(ctx context.Context, nodeIDs storj.NodeIDList)
 func (service *Service) GetParticipatingNodes(ctx context.Context) (records []nodeselection.SelectedNode, err error) {
 	defer mon.Task()(&ctx)(&err)
 
-	// TODO add as of system time.
-	return service.db.GetParticipatingNodes(ctx, service.config.Node.OnlineWindow, 0)
+	return service.db.GetParticipatingNodes(ctx, service.config.Node.OnlineWindow, service.config.AsOfSystemTime)
 }
 
 // UpdateReputation updates the DB columns for any of the reputation fields.

scripts/testdata/satellite-config.yaml.lock

@@ -802,6 +802,9 @@ identity.key-path: /root/.local/share/storj/identity/satellite/identity.key
 # how many concurrent orders to process at once. zero is unlimited
 # orders.orders-semaphore-size: 2
 
+# default AS OF SYSTEM TIME for service
+# overlay.as-of-system-time: -10s
+
 # the location of the maxmind database containing geoip country information
 # overlay.geo-ip.db: ""