YQ-3405 fixed endless retries for external error (ydb-platform#6722)

Author: GrigoriyPA

ydb/core/fq/libs/config/protos/control_plane_storage.proto

@@ -24,11 +24,15 @@ message TQueryMapping {
 
 // 1. StatusCode(s) are handled with defined policies, non-unique StatusCode(s) across all policies is UB
 // 2. RetryCount and RetryPeriodMs are used to calculate actual RetryRate, if it exceeds RetryCount, query is aborted
+//    - Number of retries during RetryPeriod time less than 2 * RetryCount due to RetryRate
 // 3. BackoffPeriodMs is factor of RetryRate to delay query execution before next retry
-// 4. There are no default retry policy, all unhandled statuses are fatal
+// 4. RetryLimit is hard limit for amount query retry count, after that query is aborted
+//    - If RetryLimit = 0, query can be abborted only by RetryRate
+// 5. There are no default retry policy, all unhandled statuses are fatal
 
 message TRetryPolicy {
     uint64 RetryCount = 1;
+    uint64 RetryLimit = 4;
     string RetryPeriod = 2;
     string BackoffPeriod = 3;
 }

ydb/core/fq/libs/control_plane_storage/config.cpp

@@ -50,10 +50,11 @@ TControlPlaneStorageConfig::TControlPlaneStorageConfig(const NConfig::TControlPl
     for (const auto& mapping : Proto.GetRetryPolicyMapping()) {
         auto& retryPolicy = mapping.GetPolicy();
         auto retryCount = retryPolicy.GetRetryCount();
+        auto retryLimit = retryPolicy.GetRetryLimit();
         auto retryPeriod = GetDuration(retryPolicy.GetRetryPeriod(), TDuration::Hours(1));
         auto backoffPeriod = GetDuration(retryPolicy.GetBackoffPeriod(), TDuration::Zero());
         for (const auto statusCode: mapping.GetStatusCode()) {
-            RetryPolicies.emplace(statusCode, TRetryPolicyItem(retryCount, retryPeriod, backoffPeriod));
+            RetryPolicies.emplace(statusCode, TRetryPolicyItem(retryCount, retryLimit, retryPeriod, backoffPeriod));
         }
     }
 

ydb/core/fq/libs/control_plane_storage/internal/task_ping.cpp

@@ -156,7 +156,7 @@ TPingTaskParams ConstructHardPingTask(
                 internal.clear_operation_id();
             }
 
-            TRetryPolicyItem policy(0, TDuration::Seconds(1), TDuration::Zero());
+            TRetryPolicyItem policy(0, 0, TDuration::Seconds(1), TDuration::Zero());
             auto it = retryPolicies.find(request.status_code());
             auto policyFound = it != retryPolicies.end();
             if (policyFound) {
@@ -183,7 +183,7 @@ TPingTaskParams ConstructHardPingTask(
                 TStringBuilder builder;
                 builder << "Query failed with code " << NYql::NDqProto::StatusIds_StatusCode_Name(request.status_code());
                 if (policy.RetryCount) {
-                    builder << " (failure rate " << retryLimiter.RetryRate << " exceeds limit of "  << policy.RetryCount << ")";
+                    builder << " (" << retryLimiter.LastError << ")";
                 }
                 builder << " at " << Now();
 

ydb/core/fq/libs/control_plane_storage/util.cpp

@@ -28,7 +28,16 @@ bool TRetryLimiter::UpdateOnRetry(const TInstant& lastSeenAt, const TRetryPolicy
             RetryRate = 0.0;
         }
     }
-    bool shouldRetry = RetryRate < policy.RetryCount;
+
+    bool shouldRetry = true;
+    if (RetryRate >= policy.RetryCount) {
+        shouldRetry = false;
+        LastError = TStringBuilder() << "failure rate " << RetryRate << " exceeds limit of "  << policy.RetryCount;
+    } else if (policy.RetryLimit && RetryCount >= policy.RetryLimit) {
+        shouldRetry = false;
+        LastError = TStringBuilder() << "retry count reached limit of "  << policy.RetryLimit;
+    }
+
     if (shouldRetry) {
         RetryCount++;
         RetryCounterUpdatedAt = now;
@@ -140,6 +149,7 @@ NConfig::TControlPlaneStorageConfig FillDefaultParameters(NConfig::TControlPlane
             policyMapping.AddStatusCode(NYql::NDqProto::StatusIds::EXTERNAL_ERROR);
             auto& policy = *policyMapping.MutablePolicy();
             policy.SetRetryCount(10);
+            policy.SetRetryLimit(40);
             policy.SetRetryPeriod("1m");
             policy.SetBackoffPeriod("1s");
         }

ydb/core/fq/libs/control_plane_storage/util.h

@@ -15,10 +15,11 @@ namespace NFq {
 class TRetryPolicyItem {
 public:
     TRetryPolicyItem() = default;
-    TRetryPolicyItem(ui64 retryCount, const TDuration& retryPeriod, const TDuration& backoffPeriod)
-    : RetryCount(retryCount), RetryPeriod(retryPeriod), BackoffPeriod(backoffPeriod)
+    TRetryPolicyItem(ui64 retryCount, ui64 retryLimit, const TDuration& retryPeriod, const TDuration& backoffPeriod)
+    : RetryCount(retryCount), RetryLimit(retryLimit), RetryPeriod(retryPeriod), BackoffPeriod(backoffPeriod)
     { }
     ui64 RetryCount = 0;
+    ui64 RetryLimit = 0;
     TDuration RetryPeriod = TDuration::Zero();
     TDuration BackoffPeriod = TDuration::Zero();
 };
@@ -32,6 +33,7 @@ class TRetryLimiter {
     ui64 RetryCount = 0;
     TInstant RetryCounterUpdatedAt = TInstant::Zero();
     double RetryRate = 0.0;
+    TString LastError;
 };
 
 bool IsTerminalStatus(FederatedQuery::QueryMeta::ComputeStatus status);