From 7fb0c9387d9eb06ddbf9e46431d8af47afb5d7d4 Mon Sep 17 00:00:00 2001
From: Jernej Kos <jernej@kos.mx>
Date: Thu, 2 Apr 2020 11:51:30 +0200
Subject: [PATCH] go/txsource/queries: Introduce a per-iteration timeout

The purpose of this timeout is to prevent the client being stuck and treating
that as an error instead.
---
 .../cmd/debug/txsource/workload/queries.go    | 113 ++++++++++--------
 1 file changed, 65 insertions(+), 48 deletions(-)

diff --git a/go/oasis-node/cmd/debug/txsource/workload/queries.go b/go/oasis-node/cmd/debug/txsource/workload/queries.go
index 31c9e05a3ae..88c3238b562 100644
--- a/go/oasis-node/cmd/debug/txsource/workload/queries.go
+++ b/go/oasis-node/cmd/debug/txsource/workload/queries.go
@@ -39,6 +39,11 @@ const (
 	queriesEarliestHeightRatio = 0.1
 	// Ratio of queries that should query latest available height.
 	queriesLatestHeightRatio = 0.1
+
+	// queriesIterationTimeout is the combined timeout for running all the queries that are executed
+	// in a single iteration. The purpose of this timeout is to prevent the client being stuck and
+	// treating that as an error instead.
+	queriesIterationTimeout = 60 * time.Second
 )
 
 // QueriesFlags are the queries workload flags.
@@ -422,6 +427,61 @@ func (q *queries) doRuntimeQueries(ctx context.Context, rng *rand.Rand) error {
 	return nil
 }
 
+func (q *queries) doQueries(ctx context.Context, rng *rand.Rand) error {
+	block, err := q.consensus.GetBlock(ctx, consensus.HeightLatest)
+	if err != nil {
+		return fmt.Errorf("consensus.GetBlock error: %w", err)
+	}
+
+	// Determine the earliest height that we can query.
+	earliestHeight := int64(1)
+	if numKept := viper.GetInt64(CfgConsensusNumKeptVersions); numKept < block.Height {
+		earliestHeight = block.Height - numKept
+	}
+
+	// Select height at which queries should be done. Earliest and latest
+	// heights are special cased with increased probability to be selected.
+	var height int64
+	p := rng.Float32()
+	switch {
+	case p < queriesEarliestHeightRatio:
+		height = earliestHeight
+	case p < queriesEarliestHeightRatio+queriesLatestHeightRatio:
+		height = block.Height
+	default:
+		// [earliestHeight, block.Height]
+		height = rng.Int63n(block.Height-earliestHeight+1) + earliestHeight
+	}
+
+	q.logger.Debug("Doing queries",
+		"height", height,
+		"height_latest", block.Height,
+	)
+
+	if err := q.doConsensusQueries(ctx, rng, height); err != nil {
+		return fmt.Errorf("consensus queries error: %w", err)
+	}
+	if err := q.doSchedulerQueries(ctx, rng, height); err != nil {
+		return fmt.Errorf("scheduler queries error: %w", err)
+	}
+	if err := q.doRegistryQueries(ctx, rng, height); err != nil {
+		return fmt.Errorf("registry queries error: %w", err)
+	}
+	if err := q.doStakingQueries(ctx, rng, height); err != nil {
+		return fmt.Errorf("staking queries error: %w", err)
+	}
+	if err := q.doRuntimeQueries(ctx, rng); err != nil {
+		return fmt.Errorf("runtime queries error: %w", err)
+	}
+
+	q.logger.Debug("Queries done",
+		"height", height,
+		"height_latest", block.Height,
+	)
+
+	return nil
+}
+
 func (q *queries) Run(gracefulExit context.Context, rng *rand.Rand, conn *grpc.ClientConn, cnsc consensus.ClientBackend, fundingAccount signature.Signer) error {
 	ctx := context.Background()
 
@@ -458,57 +518,14 @@ func (q *queries) Run(gracefulExit context.Context, rng *rand.Rand, conn *grpc.C
 	q.runtimeGenesisRound = resp.Header.Round
 
 	for {
-		block, err := q.consensus.GetBlock(ctx, consensus.HeightLatest)
-		if err != nil {
-			return fmt.Errorf("consensus.GetBlock error: %w", err)
-		}
-
-		// Determine the earliest height that we can query.
-		earliestHeight := int64(1)
-		if numKept := viper.GetInt64(CfgConsensusNumKeptVersions); numKept < block.Height {
-			earliestHeight = block.Height - numKept
-		}
-
-		// Select height at which queries should be done. Earliest and latest
-		// heights are special cased with increased probability to be selected.
-		var height int64
-		p := rng.Float32()
-		switch {
-		case p < queriesEarliestHeightRatio:
-			height = earliestHeight
-		case p < queriesEarliestHeightRatio+queriesLatestHeightRatio:
-			height = block.Height
-		default:
-			// [earliestHeight, block.Height]
-			height = rng.Int63n(block.Height-earliestHeight+1) + earliestHeight
-		}
+		loopCtx, cancel := context.WithTimeout(ctx, queriesIterationTimeout)
 
-		q.logger.Debug("Doing queries",
-			"height", height,
-			"height_latest", block.Height,
-		)
-
-		if err := q.doConsensusQueries(ctx, rng, height); err != nil {
-			return fmt.Errorf("consensus queries error: %w", err)
-		}
-		if err := q.doSchedulerQueries(ctx, rng, height); err != nil {
-			return fmt.Errorf("scheduler queries error: %w", err)
-		}
-		if err := q.doRegistryQueries(ctx, rng, height); err != nil {
-			return fmt.Errorf("registry queries error: %w", err)
-		}
-		if err := q.doStakingQueries(ctx, rng, height); err != nil {
-			return fmt.Errorf("staking queries error: %w", err)
-		}
-		if err := q.doRuntimeQueries(ctx, rng); err != nil {
-			return fmt.Errorf("runtime queries error: %w", err)
+		err := q.doQueries(loopCtx, rng)
+		cancel()
+		if err != nil {
+			return err
 		}
 
-		q.logger.Debug("Queries done",
-			"height", height,
-			"height_latest", block.Height,
-		)
-
 		select {
 		case <-time.After(1 * time.Second):
 		case <-gracefulExit.Done():